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'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
===Hardware longevity===<br />
<br />
All digital devices are susceptible to two problems which cause the majority of failures; overheating and [http://en.wikipedia.org/wiki/Voltage_spike voltage spikes]. A [http://en.wikipedia.org/wiki/Underwriters_Labs UL] approved [http://en.wikipedia.org/wiki/Surge_protector surge protector] with a low clamping voltage can divert surges to ground if your house or office wiring has a good ground. Ground testers are available from hardware stores to tell if your outlets are well grounded, but it's guaranteed that a surge protector cannot work if attached to an ungrounded outlet.<br />
<br />
Voltage spikes, also called power surges, can travel over power lines, phone lines, [http://en.wikipedia.org/wiki/DSL DSL] lines and [http://en.wikipedia.org/wiki/Cable_Internet_access cable] lines. <br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://upload.wikimedia.org/wikipedia/commons/1/1f/File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)].<br />
<br />
All three have common elements; a Menu button at upper or lower left, a bar at top or bottom which shows running programs, and on the right side of that bar in Windows and Linux there's an area showing the time and icons for programs which are always running. Linux and Mac OS X have a 'dock' which allows you to quickly pick the programs you run the most.<br />
<br />
It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft OneDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=70638Computer Basics2014-06-12T20:43:44Z<p>K7aay: /* Data */ remove reference to Ubuntu One</p>
<hr />
<div>{{migrate}}<br />
'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
===Hardware longevity===<br />
<br />
All digital devices are susceptible to two problems which cause the majority of failures; overheating and [http://en.wikipedia.org/wiki/Voltage_spike voltage spikes]. A [http://en.wikipedia.org/wiki/Underwriters_Labs UL] approved [http://en.wikipedia.org/wiki/Surge_protector surge protector] with a low clamping voltage can divert surges to ground if your house or office wiring has a good ground. Ground testers are available from hardware stores to tell if your outlets are well grounded, but it's guaranteed that a surge protector cannot work if attached to an ungrounded outlet.<br />
<br />
Voltage spikes, also called power surges, can travel over power lines, phone lines, [http://en.wikipedia.org/wiki/DSL DSL] lines and [http://en.wikipedia.org/wiki/Cable_Internet_access cable] lines. <br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://upload.wikimedia.org/wikipedia/commons/1/1f/File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)].<br />
<br />
All three have common elements; a Menu button at upper or lower left, a bar at top or bottom which shows running programs, and on the right side of that bar in Windows and Linux there's an area showing the time and icons for programs which are always running. Linux and Mac OS X have a 'dock' which allows you to quickly pick the programs you run the most.<br />
<br />
It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Store_Prices&diff=70525Store Prices2014-05-16T00:46:09Z<p>K7aay: /* Drives (other than hard drives) */ spelling fix - no change to prices</p>
<hr />
<div>{{RightTOC}}<br />
'''N.B.''' This page is a tool to assist store staff in pricing items. Prices found here are not to be considered quotes or advertisements in any way. The actual price is what store staff says it is; don't lose sight of this important distinction.<br />
<br />
Note: ECP = "Ebay Completed Price"<br />
<br />
==A/C Adapters==<br />
* Behind the counter wall warts - $5<br />
* Bin of broken dreams wall warts - $3<br />
* Cell phone - $3<br />
* Car chargers - $3<br />
* Printers - $5<br />
* Behind the counter laptop adapters - See [http://wiki.freegeek.org/index.php/Store_Prices#Laptops_and_Accessories Laptops and Accessories]<br />
* Bin of broken dreams laptop adapters - $8<br />
<br />
==Audio/Video==<br />
* '''DVD Players''' - $10 with remote stashed in RRR bin<br />
* '''iPods''' Priced by style, generation, and size<br />
** Classic - $15-$50<br />
** Mini - $10-$15<br />
** Nano - $10-$35<br />
** Shuffle - $5-$20<br />
** Touch - $24-$45<br />
<br />
==Cables==<br />
* '''Audio/Video'''<br />
** RCA - $2, Long As Marked<br />
** S-Video - $2<br />
** Coax - $2<br />
** Monster, AR, Phoenix Gold, Fancy - $3-$5 or priced as marked.<br />
* '''Cat5'''<br />
** Short - $2<br />
** Long - $0.30/ft<br />
** Custom $5 service fee + $0.30/ft when available<br />
* '''Monitor''' <br />
** VGA, DVI - $2<br />
** Monitor extensions - $2<br />
** DVI to VGA adapters - $3<br />
** HDMI Cables - $8<br />
** DisplayPort - $5<br />
** MiniDP adapters - $5-$8 depending on other end<br />
** Mac video adapters - $3-$8<br />
* '''Interface Cables'''<br />
** IDE - $2<br />
** Floppy - $2<br />
** SATA - $2<br />
** SCSI - $2<br />
* '''USB'''<br />
** USB A to B (printer) - $2<br />
** USB A to mini - $2<br />
** USB Extension - $2<br />
** USB to misc. proprietary thingy - $2<br />
** USB A to micro - $5<br />
*'''Firewire'''<br />
** Firewire 400, 800, or mini - $2<br />
** Firewire 400 to 800 - $5<br />
* '''Miscellaneous Cables'''<br />
** Game Cables - $3-$5<br />
** KVM cable sets - $3<br />
** Misc. adapters - $2<br />
** PS/2 - $2<br />
** Parallel (including printer) - $1<br />
** Phone - $0.50<br />
** Power cord - $2 or free with devices that require one<br />
** Power strip - $3 or as marked<br />
<br />
==Cards==<br />
* '''Controller cards'''<br />
** IDE - $5<br />
** SCSI - $5<br />
** SATA - $5<br />
** SAS - check online<br />
* '''NIC'''<br />
** 10/100 PCI - $5<br />
** Gigabit - $10<br />
** Modem cards - $5<br />
* '''Sound'''<br />
** PCI - $5<br />
** PCIe - look up<br />
* '''USB/Firewire''' - $5<br />
* '''TV Tuner Cards''' - $5<br />
* '''Video Cards''' - See [[Media:store_pricing_cheat.ods|Store Pricing Sheet]]. For cards <b>not</b> on the pricing sheet:<br />
** Low end $5<br />
** 256mb+ price as marked<br />
**TV Tuner Cards - analog $5 digital as marked<br />
<br />
==ATX Cases==<br />
* $8 and up!<br />
* Nicer cases are priced as marked<br />
<br />
== Computer Systems ==<br />
* System pricing is variable, based on the specifications of the computer and can range from $100-$650 or thereabouts<br />
<br />
==Drives (other than hard drives)==<br />
* '''CD-RW''' - $5<br />
* '''DVD-ROM''' - $5<br />
* '''DVD-ROM + CD-RW''' Combo drives - $5<br />
* '''DVD-RW''' - $15<br />
* '''External DVD-RW''' - $20 - $25<br />
* '''External Drive Enclosures'''<br />
** IDE - $10<br />
** SATA - $15, <br />
** $5 extra per feature (ie. eSATA, USB 3.0, etc.)<br />
* '''3.5" Floppy''' - $10<br />
* '''Zip Disk''' - $20<br />
<br />
==Hard Drives==<br />
===Desktop (3.5")===<br />
<br />
*'''IDE'''<br />
** 40 GB and under - no longer sold<br />
** 80 GB - $10 2 for $15<br />
** 100 GB - $12<br />
** 120 GB - $15<br />
** 160 GB - $20<br />
** 200 GB - $25<br />
** 250 GB - $30<br />
** 320 GB - $35<br />
** 400 GB - $40<br />
** 500 GB - $50<br />
<br />
*'''SATA'''<br />
** 80 GB - $15<br />
** 120 GB - $20<br />
** 160 GB - $25<br />
** 200 GB - $30<br />
** 250 GB - $35<br />
** 320 GB - $40<br />
** 400 GB - $45<br />
** 500 GB - $50<br />
** 750 GB - $55<br />
** 1 TB - $65<br />
** 2 TB - $90<br />
<br />
*'''SCSI''' <br />
<br />
** 72 GB - $5<br />
** 146 GB - $10<br />
<br />
===Laptop (2.5")===<br />
*'''IDE'''<br />
** Below 20GB - $0.50 per GB<br />
** 20 GB - $10<br />
** 30 GB - $15<br />
** 40 GB - $20<br />
** 60 GB - $25 (typically unavailable)<br />
** 80 GB - $30 (typically unavailable)<br />
** 100 GB - $35 (typically unavailable)<br />
** 120 GB - $40 (typically unavailable)<br />
** 160 GB - $45<br />
** 200 GB - $50<br />
** 250 GB - $55<br />
** 300/320 GB - $55<br />
<br />
*'''SATA'''<br />
** Below 20GB - $0.50 per GB<br />
** 20 GB - $15<br />
** 30 GB - $15<br />
** 40 GB - $15<br />
** 60 GB - $20 (typically unavailable)<br />
** 80 GB - $25 (typically unavailable)<br />
** 100 GB - $30 (typically unavailable)<br />
** 120 GB - $35 (typically unavailable)<br />
** 160 GB - $40<br />
** 200 GB - $45<br />
** 250 GB - $50<br />
** 300/320 GB - $55<br />
** 500 GB - $60<br />
<br />
==Keyboards==<br />
* PS2 - $4 or as marked<br />
* usb - $6 or as marked<br />
* Fancy - as marked<br />
<br />
==Mice==<br />
* PS2 - $2 or as marked<br />
* usb - $5 or as marked<br />
* either with rolley ball - $2<br />
<br />
==Wireless Keyboard and Mice==<br />
Priced by quality<br />
* Just mouse - as marked<br />
* Just keyboard - as marked<br />
* Mouse/Keyboard - as marked<br />
* Bluetooth - priced as marked<br />
<br />
==KVM==<br />
* Cables - $3<br />
* Switches - $5-$10<br />
<br />
==Laptops and Accessories==<br />
* System pricing is variable, based on the specifications, condition and battery life of the computer and can range from $100-$650 or thereabouts<br />
* '''Laptop Bags''' - $5 or priced as marked<br />
<br />
* '''Laptop Power Supplies'''<br />
** < 3.5 Amps - $10<br />
** &ge; 3.5 Amps or more - $20 or priced as marked<br />
** Mac Laptop Chargers - $15<br />
<br />
* '''PCMCIA Cards'''<br />
** Misc. Cards - $4 or priced as marked<br />
** Wireless cards - $8<br />
<br />
==Memory==<br />
<br />
===SDRAM===<br />
* PC133<br />
** 128 MB - $3<br />
** 256 MB - $5<br />
** 512 MB - $10<br />
<br />
===DDR===<br />
<br />
* 128 MB - $1<br />
* 256 MB - $3<br />
* 512 MB - $5<br />
* 1 GB - $15<br />
<br />
===DDR 2===<br />
<br />
* 256 - $3<br />
* 512 - $5<br />
* 1GB - $10<br />
* 2GB - $20<br />
<br />
===DDR 3===<br />
<br />
* 1GB - $5<br />
* 2GB - $10<br />
* 4GB - $15<br />
* 8GB - as marked<br />
<br />
===RAMBUS===<br />
Limited Availability!<br />
* 2x64 mb - $10<br />
* 2x128 mb - $20<br />
* 2x256 mb - $25<br />
* 2x512 mb (rare!) - $45<br />
<br />
Laptop Memory<br />
<br />
* same as desktop ram<br />
<br />
==Monitors==<br />
* LCD<br />
** 19" - $50 Base Price<br />
** 20" - $55 Base Price<br />
** 21" - $60 Base Price<br />
** 22" - $65 Base Price<br />
<br />
Add $5 for Widescreen format, speakers, rotating screen, and general fanciness.<br />
Dead pixels, beige color, scratches, janky power subtract $5 from this base.<br />
If it's really, really fancy, double check the model details online. <br />
<br />
* Larger monitors are priced as marked.<br />
<br />
==Motherboards==<br />
Depending on the capabilities - as marked<br />
* Sold without processors<br />
<br />
==Networking Devices==<br />
* '''DSL and Cable Modems''' - $5.00 untested<br />
* '''Wired Switches and Routers'''<br />
** 4 port - $5<br />
** 8 port - $10<br />
** 16 port - $15<br />
** Rackmount/enterprise - eBay<br />
* '''Gigabit Switches'''<br />
** 4 Port - $10<br />
** 8 Port - $15<br />
** 16 Port - $20<br />
* '''Wireless Routers'''<br />
** 802.11 B - $8<br />
** 802.11 G - $15<br />
** 802.11 N - $25<br />
* '''Wireless Adaptors'''<br />
** B - $10<br />
** G - $15<br />
** N - $20<br />
** Airport - $15<br />
** Airport Extreme - $25<br />
** Wireless Range extenders - $10<br />
<br />
==Power Supplies==<br />
GENERIC<br />
* 250 watt and under - $5.00<br />
* 300 to 399 watt - $10.00<br />
* 400 to 499 watt - $15.00<br />
* 500 to 599 watt - $20.00<br />
* 600 to 699 watt - $25.00<br />
* 700 watts and up - priced as marked<br />
<br />
FANCY<br />
Priced as marked<br />
<br />
==Printers and Scanners==<br />
* Printers - $20-$40<br />
* Scanners - $10<br />
<br />
==Processors==<br />
* '''Fans/Heatsinks'''<br />
** Case Fans - $1-$3<br />
** Heatsink/Fan combo - $3-$10 or priced as marked<br />
<br />
* '''Processors'''<br />
* Pentium 4s - all speeds $5<br />
* Pentium D - $10<br />
* Athlon 64 - 939 or AM2 - As marked<br />
* Athlon 64x2 - Socket 939 - As marked<br />
* Athlon 64x2 - Socket AM2 - As marked<br />
** Ex: Up to 4000+ - As marked<br />
** Ex: 4200+ and above - As marked<br />
----<br />
* Pentium Dual-cores - $15<br />
* Intel Core 2 - priced as marked.<br />
<br />
==Shwag==<br />
* Shirts - $12<br />
* Tote bags - $8<br />
* Stickers - $0.50<br />
* Pins - $1.00<br />
* 'Ubuntu for Non-Geeks' book - $25 (volunteers: $20)<br />
<br />
==Speakers==<br />
* PC case speakers - $1<br />
* Unpowered (external) - $5<br />
* Powered - As marked by quality<br />
* Subwoofer Systems - as marked by quality<br />
* 5.1 systems and home audio - as marked (use eBay)<br />
<br />
==Thumb/Flash Drives==<br />
*512 MB - $1<br />
*1 GB- $2<br />
*2 GB - $3<br />
*4 GB - $4<br />
*8 GB - $6<br />
*16 GB - $8<br />
*32 GB - $15<br />
*64 GB - $25<br />
*128 GB - Online<br />
*256 GB - Online<br />
+extra for special features (size, fingerprint reader, hard case, etc.)<br />
<br />
==Miscellaneous==<br />
* Free Table Stuff - Free, but the table is not for sale<br />
* '''Distro CDs''' - $1.00<br />
* '''Old Media'''<br />
** Floppies - $.25<br />
** Most others - $1-$2<br />
<br />
Items of unknown value may be price checked on eBay, and will not exceed 60% ECP.<br />
<br />
[[Category: Thrift Store]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Tech_Support&diff=70454Tech Support2014-04-30T18:15:02Z<p>K7aay: Revised price of post warranty support, current OS version & removed Mac OS X from Stuff We Don't Support</p>
<hr />
<div>{{migrate}}<br />
Free Geek tech support is offered free of charge to:<br />
<br />
* Adopters and hardware grant recipients for one year<br />
* Thrift store customers for six months after original purchase<br />
* We will provide tech support for one year after the warranty period at $15 per issue plus the cost of any parts, we do not replace machines that are out of warranty<br />
*support beyond this period is entirely at our discretion<br />
<br />
This support includes replacement of defective parts if necessary, but does not include any guarantee that programs or hardware added by the user will function. We will repair or replace defective hardware and ensure that the system and its components function under current, Long Term Support releases of the Ubuntu operating system, currently 12.04. Changes to the original system hardware may void this warranty.<br />
<br />
{|cellspacing="1px" style="background-color:#f8fcff"<br />
<br />
| width="70%" style="border: 1px solid #6688AA; background-color:#FFFFFF; padding:1em;" valign="top"|<br />
<br />
== Contact Info and Hours ==<br />
{{Template:Tech Support Hours}}<br />
* '''By phone''' - call the main Free Geek number during support hours - {{phone}} option 6. If you call outside of our regular hours, please leave a message with your name, phone number and a description of your problem. We will call you back as quickly as we can.<br />
* '''Walk in''' - Come to the reception area during tech support hours and they will direct you back to the tech support area. Please fill out an intake form clearly and completely<br />
* '''Email''' - send an email to support AT freegeek.org<br />
<br />
|width="30%" align="left" style="border: 1px solid #6688AA; background-color:#efefef;padding:1em;" valign="top" |<br />
==Pages related to Tech Support==<br />
; [http://todo.freegeek.org/ RT]<br />
: Our ticket tracking system. See the Tech Support queue.<br />
; [https://help.ubuntu.com/ Official Ubuntu Documentation]<br />
: A great repository of how-tos and support topics<br />
; [http://ubuntuforums.org/ http://ubuntuforums.org/]<br />
: User forums<br />
; [http://wiki.freegeek.org/index.php/Category:Tech_support Tech Support Category]<br />
: Internally created documentation<br />
; [[Multimedia and DVDs in Ubuntu]]<br />
: How to get Flash & DVD's working on your system<br />
; [[Tech Support Orientation]]<br />
; [[Tech Support Howto]]<br />
: For learning how to work in tech support<br />
; [[Tech Support Intake Guidelines]]<br />
: Procedures and policies for how work orders and donations are handled<br />
|}<br />
{|cellspacing="1px" style="background-color:#f8fcff"<br />
<br />
| width="100%" style="border: 1px solid #6688AA; background-color:#FFFFFF; padding:1em;" valign="top"|<br />
<br />
== Services ==<br />
Many services covered under warranty we can provide for free, but we occasionally need to charge a fee for difficult or non-standard support. When we cannot support an issue, we can refer interested parties to outside agencies.<br />
=== Stuff We Support ===<br />
==== Software ====<br />
* Ubuntu<br />
* Restoring the original configuration of a system <br />
* Updating to later versions of Ubuntu<br />
* Driver installation (subject to availability)<br />
* Software to make media work<br />
* Data transfer to a Free Geek system<br />
* Data backup/recovery from a Free Geek system or system being donated<br />
* Wireless devices without native driver (we'll try!)<br />
<br />
====Hardware====<br />
* Easy to install hardware from the store<br />
* Printers from the store<br />
* 3G/WiMax configuration<br />
* Your computer<br />
<br />
=== Stuff We Don't Support ===<br />
* Windows <br />
* WINE ('''[http://wiki.freegeek.org/index.php/Games_Under_Linux Click here for more information on how to run games in WINE]'''). If you'd like to know more about WINE, look for some [http://www.freegeek.org/about/education/ Free Geek classes here].<br />
* Home networking<br />
* Consultation<br />
* Anything you broke<br />
* Systems not from Free Geek<br />
* Hardware without available drivers<br />
* Aesthetic concerns (loud, ugly, smells)<br />
* Parts not from the thrift store<br />
* Gross negligence on your part<br />
<br />
|}<br />
<br />
[[Category:Structure]]<br />
[[Category:Programs]]<br />
[[Category:Tech support]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Where_Is_Everything_Notes&diff=70272Where Is Everything Notes2014-04-04T22:48:19Z<p>K7aay: </p>
<hr />
<div>{{migrate}}<br />
<br />
== Filesystem Hierarchy: ==<br />
*root filesystem:<br />
:Refers to '/', the top level of the directory structure (aka base). Use family tree as metaphor.<br />
*home/:<br />
:Where individuals store their personal files and settings.<br />
*root/:<br />
:Where the root user stores its personal files and settings. Explain some about what the root user is.<br />
*boot/:<br />
:A folder containing the kernel, its related files, and the bootloader's related files -- this is what is essential to begin the bootstrap<br />
*etc/:<br />
:Where all system level config files and setting should go (passwd, network/interfaces, X11 stuff), as well as the system startup scripts (init.d, rc?.d).<br />
*dev/:<br />
:Contains files that coorespond to physical or virtual hardware that the kernel is aware of or of the potential of (like hda for the primary master drive, or ttyS0 for the COM1 serial port (as well as a bunch more tty*s for virtual terminals), as well as resonably named aliases (like modem and cdrom).<br />
*mnt/:<br />
:Where temporary filesystem mountings should happen, such as over nfs, or drives you just put in. Often takes the role of media. History of physically mounting tape reels.<br />
*floppy/:<br />
:Where debian mounts the floppy drive.<br />
*cdrom/:<br />
:Where debian mounts the cdrom drive.<br />
*bin/:<br />
:A folder that holds all the vitally necessary executable programs for users on running a linux system (like 'ls' and 'rm').<br />
*sbin/:<br />
:A folder that holds programs vitally necessary for running linux, but which should only be run by the super user and system tools (like 'ifconfig').<br />
*lib/:<br />
:Where all the vital commands keep their needed libraries. (like dlls) <br />
*lib/modules/:<br />
:Where kernel modules go.<br />
*usr/:<br />
:This has a deep structure which to some part mirrors the root filesystem, and is meant to be the install location for programs and libraries which are not vitally necessary for the system to minimally boot up (like X/gui progs, aumix, &c.).<br />
*usr/local/:<br />
:This mirrors the root filesystem yet again, and is used for when the system administrator installs something from scratch as opposed to installing via the package management system.<br />
*tmp/:<br />
:A folder for holding temporary files that will be deleted after they've been there for too long.<br />
*var/:<br />
:A folder for extra files, like log files, databases, web pages or undelivered mail. Throw in history of files with unknown size.<br />
*opt/:<br />
:A folder some applications use to store files, but without as much structure as to what to keep here or how.<br />
*proc/:<br />
:A folder with pretend files for all the running processes, providing information about what is currently happening, as well as a few files for information about the running hardware (cpuinfo, pci, interupts). proc does not exist on all unices -- the files are dependent on the mounting of proc, a special device. This will be its own class on a later day.<br />
<br />
== Searching: ==<br />
*locate/updatedb:<br />
:`locate word` will find all places where 'word' is, but it takes having run `updatedb` recently, usually once a day as a cron job. "updatedb" can only be run as root.<br />
*find:<br />
:Find is really powerful and complicated, but doing `find / -iname \*word\*` is the same as `locate word`, only it takes a lot longer. better is to do `find /a/sub/directory -iname word`, as that will take less time.<br />
*which/whereis:<br />
:`which command` will tell me where the command is (so like `which ls`)<br />
:`whereis command` will tell me the same, as well as where all of the command's man pages are.<br />
*cd:<br />
:There are special directory names that are always around. '.' is whatever directory you're in right now (so `cd .` does absolutely nothing). '..' is one directory above your current location (and '../../..' is three higher). '~' means the home directory of whoever you currently are. The 'cd' command also has some special behavior: `cd` by itself is like `cd ~`. `cd -` will take you to the last place you were before the last time you changed directories.<br />
*$PATH:<br />
:This is a list of directories (so '/bin:/usr/bin' is '/bin' and '/usr/bin') that the command line and which and whereis (and tab competion) look to find programs i can run without filling in their whole name (so i can run `ls` instead of `/bin/ls`). To see this, you have to type echo $PATH<br />
== Help: ==<br />
*man:<br />
:`man command` usually gives a manual page for a command on how to use it and who wrote it and stuff.There should be a class on how to read man pages.<br />
*help options:<br />
:`command --help` usually give a little description of how to use the command. Also, -H and -h sometimes. --help is the standard for all GNU commands, which are frequently not used on BSD systems so commands like tar will frequently not give you much info when you run tar --help on a bsd system.<br />
*help:<br />
:`help command` will give little description of how to use the builtin shell functions (for, alias, &c.).<br />
*info:<br />
:Some commands use info instead of man. It's weird to use, but has the same basic information.<br />
*apropos:<br />
:`apropos word` searches through all the man pages' one line descriptions for 'word'. Useful if i know what i want to do, but forget exactly how to do it.<br />
*/usr/share/doc:<br />
:Some programs put extra documentation and manuals in this directory.On debian, all packages are required to have documentation here.<br />
== howtos / Links: ==<br />
*http://linuxdoc.org has a huge manual on how to do things in linux (so like "how do i use a modem" or "how do i compile a kernel"), also known as 'the linux documentation project' or 'the howtos'.<br />
*[http://www.unix.org/single_unix_specification/onlinepubs/000095399/basedefs/xbd_chap10.html POSIX 1003.1 Directory Structure and Devices]- defines only /, /dev, /tmp, /dev/console, /dev/null, and /dev/tty.<br />
*[http://www.pathname.com/fhs/pub/fhs-2.3.html Filesystem Heirarcy Standard (FHS) 2.3] is more complete.<br />
*[http://www.debian.org/doc/packaging-manuals/fhs/ FHS Debian copy] should (always?) contain the version relevant to Debian (currently 2.1)<br />
== Software: ==<br />
*apt-cache search:<br />
:`apt-cache search word` searches through the on disk database of software packages i can install onto my system with 'word' in its name or description.<br />
*packages.debian.org:<br />
:This website searches through an online database of all possible packages to be installed (useful for knowing which debian system to use to get a certain package).<br />
*freshmeat.net:<br />
:For software that isn't in a debian package, this is a good place to look, as searches are ordered in terms of recent updates.<br />
*sourceforge.net:<br />
:For a more thorough compilation, sourceforge.net has most open source projects.<br />
*Other distros:<br />
:Most other linux distributions offer similar ways to search for software. Check with each one to find out how.<br />
== Other: ==<br />
*dpkg -L/-S:<br />
:`dpkg -L package` will list out all the files that were installed when the package was installed. `dpkg -S /absolute/path/to/filename` searches for the package that installed that particular file.<br />
*w/finger/who:<br />
:`who` shows who's logged in. Many servers do not have this installed.<br />
:`finger` is another useful command where it is installed, and is remote-capable. The remote version of finger is considered a security hole because it allows an attacker to determine who uses a computer. <br />
:`w` show who's logged in and what they're doing.<br />
*lsof:<br />
:This gives a list of all 'open files' - files that somebody or program has opened and is either reading from or writing to it.`lsof -i` lists only those 'files' that are related to the IP network.<br />
*lsmod:<br />
:This lists all modules loaded by the kernel (like device drivers).<br />
*lspci:<br />
:This lists all the known pci cards and devices. Use `lspci -v` to learn more than i want to know.<br />
*dmesg:<br />
:This lists all the messages that happened at boot. Grep'ing this for isa is useful.<br />
<br />
[[Category:Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=70271Leaving no trace in a digital world2014-04-04T22:45:58Z<p>K7aay: </p>
<hr />
<div>{{migrate}}<br />
<br />
==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus solely on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government - M$/NSA makes it easier to hack you [http://j.mp/MSeasiertheft] “Purposeful backdoors in security products - another revelation from leaked security agency documents - benefit all hackers. If firms have allowed for weaknesses in their product sets, they don’t just open up holes for agents to exploit, but criminals too. Organised crime groups are pumping money into hunting for such vulnerabilities, placing the everyday user at ever greater risk.”<br />
<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It is far safer than just TOR or the Tor Browser Bundle. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* [http://j.mp/borderinspection Going through customs] – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Anatomy_of_a_Hack&diff=70270Anatomy of a Hack2014-04-04T22:44:36Z<p>K7aay: </p>
<hr />
<div>{{migrate}}<br />
<br />
== Anatomy of a Hack: ==<br />
<br />
'''Purpose:''' This is a class on basic security principles highlighted by real-life events and the consequences of what can happen when you do not attend to the basics of protection. <br />
<br />
'''Hypothetical situations:'''<br />
* An email arrives from iTunes. It says they found that your credit card number is bad. The email links to a website to go to, to fill out the correct credit card information. It reads in part:<br />
<br />
Please click the following link to update your credit card information<br />
and prevent disruption to your service. [http://sxserver.ru/credit.php www.itunes.com]<br />
<br />
* You receive a phone call: Sam, the head of IT, calls to ask for your password so that he can fix your computer.<br />
<br />
* An instant message comes in from a long lost cousin you don't recall, asking for your siblings' email and address.<br />
<br />
<br />
<br />
=== HBGary ===<br />
<br />
The players:<br />
<br />
[http://en.wikipedia.org/wiki/Anonymous_%28group%29 Anonymous] is a group of hacktivists who are responsible for actions that could be considered either good, bad or both. Some of their actions are illegal. <br />
<br />
[http://en.wikipedia.org/wiki/HBGary HBGary] was a technology security company which sold its products to the US Government (including the Defense Department), information assurance companies (Equifax, et al.), computer emergency response teams and computer forensic investigators. The CEO, Aaron Barr, developed a technique which he thought would unmask the leaders of Anonymous by comparing the timing of Anonymous IRC rooms to social media posts, although his lead programmer criticized his methodology. His intention was to sell the list to the FBI and other law enforcement agencies. <br />
<br />
When the Financial Times ran a story on this, Anonymous members attacked within 24 hours.<br />
<br />
==== Chronology of the attack: ====<br />
<br />
===== [http://en.wikipedia.org/wiki/SQL_injection SQL INJECTION] =====<br />
SQL injection is an old method of attack via entering portions of SQL statements into web form fields. If the website is vulnerable, the SQL can send statements to the database and get it to dump out users, passwords, credit card numbers and other information.<br />
<br />
* A [http://en.wikipedia.org/wiki/Content_management_system Content Management System(CMS)] is a system that allows for creating, editing and publishing content without a need for programming or in-depth knowledge<br />
** Wordpress, etc<br />
* HBGary used a custom CMS on their site<br />
* No CMS is 100% safe but in this case a custom CMS was used which had gaping security holes in it, leaving it open to SQL injection attacks. If an off-the-shelf product had been used, there could be thousands of users and bug reports. This custom CMS had no one reviewing it and fixing problems.<br />
* SQL injection is a technique often used to attack databases through a website. This is done by including portions of SQL statements in a web form entry field in an attempt to get the website to pass a newly formed rogue SQL command to the database (e.g. dump the database contents to the attacker). http://en.wikipedia.org/wiki/SQL_injection<br />
* This exploit was used to dump the table of usernames and passwords out of the website.<br />
* A plaintext password would appear as '''password'''<br />
* Passwords were encrypted using [http://en.wikipedia.org/wiki/Md5 MD5], but because these were not [http://en.wikipedia.org/wiki/Salt_%28cryptography%29 salted] a [http://en.wikipedia.org/wiki/Rainbow_table rainbow table] could reverse the encryption<br />
** MD5 is a cryptographic hash function<br />
*** Imagine taking something that makes '''password''' into '''qbttxpse'''<br />
*** This they did right<br />
** [http://en.wikipedia.org/wiki/Salt_%28cryptography%29 “Salting”] is adding random bits to the encrypted data to make cracking it impossible or impractical<br />
*** '''qbttxpse''' becomes something like '''qb1ttx01ps1e'''<br />
** Rainbow tables are used for reversing cryptographic hash functions<br />
*** Because the passwords were not long and they were not salted, the program was able to figure out the hash ( moving everything 1 letter ahead in our example) and reverse it into a plain-text password<br />
* Passwords and usernames were gotten<br />
<br />
===== [http://en.wikipedia.org/wiki/Root_access ROOT ACCESS] =====<br />
Also known as an admin, administrator, or superuser; this account can make system-wide changes not available to other users<br />
<br />
* Using the now-cracked passwords, the attackers were able to gain non-root access the server support.hbgary.com<br />
* Root access is full-control or adminstrative access<br />
* Using a known exploit for which the server had not been patched, they were able to take root access and removed gigabytes of information<br />
<br />
===== PASSWORD REUSE =====<br />
<br />
* Among others, high-level employees including the CEO and COO were gotten<br />
* They had exempted themselves from password complexity requirements and used 6 all lower-case letters and 2 numbers<br />
* These passwords were re-used all over the internet from Google to LinkedIn to Twitter. <br />
* Aaron Barr's, the CEO that started this, re-used this password for the companies Google Apps Mail service.<br />
* Because he was an administrator, any accounts could be gotten into simply by resetting their password.<br />
* They did this for the account of a man named [http://en.wikipedia.org/wiki/Greg_Hoglund Greg Hoglund] who founded HBGary and is known in the security world<br />
* Through reading his emails they found out that he and a Nokia employee had SSH access to a server (rootkit.com) as well as possible root passwords for that server.<br />
<br />
===== [http://en.wikipedia.org/wiki/Social_engineering_%28security%29 SOCIAL ENGINEERING] =====<br />
In the context of security, social engineering is getting people to do what you want them to through social/psychological manipulation. <br />
<br />
* At this point, Anonymous has access to most of the communications within HBGary. They know that Greg Hoglund is in Europe, two possible passwords to the server root and his security person from Nokia and contact info.<br />
* They send an email from Hoglund's account to this person. <br />
<br />
From: Greg Hoglund <greg@hbgary.com> ISun, Feb 6, 2011 at 1:59 PM<br />
To: jussi <jussij@gmail.com><br />
im in europe and need to ssh into the server. can you drop open up<br />
firewall and allow ssh through port 59022 or something vague?<br />
and is our root password still 88j4bb3rw0cky88 or did we change to<br />
88Scr3am3r88 ?<br />
thanks<br />
<br />
From: jussi jaakonaho <jussij@gmail.com> ISun, Feb 6, 2011 at 2:06 PM<br />
To: Greg Hoglund <greg@hbgary.com><br />
hi, do you have public ip? or should i just drop fw?<br />
and it is w0cky - tho no remote root access allowed<br />
<br />
From: Greg Hoglund <greg@hbgary.com> ISun, Feb 6, 2011 at 2:08 PM<br />
To: jussi jaakonaho <jussij@gmail.com><br />
no i dont have the public ip with me at the moment because im ready<br />
for a small meeting and im in a rush.<br />
if anything just reset my password to changeme123 and give me public<br />
ip and ill ssh in and reset my pw.<br />
* Once they had root access to that server they obtained further information and cracked all the poorly guarded username/password combinations again. Jussi had little reason to think he was not dealing with Greg Hoglund. The email came from Greg's account, he knew 2 of the passwords - still, Jussi might have thought to verify but the social want to help and the fact that "Greg" was in a hurry rushed him into doing it without checking.<br />
<br />
==== Aftermath ====<br />
* Aaron Barr tried to negotiate with Anonymous. He lied to them repeatedly, not realizing they had all his emails and knew the truth. <br />
* Over 40,000 internal emails, many of them containing very sensitive information, were posted to the Pirate Bay<br />
* Over 1 TB of HBGary backup data was deleted<br />
* Barr's iPad was remotely wiped<br />
* All social media accounts for Barr were used to discredit and embarrass him<br />
* HBGary's site was defaced and everything made public to shame them <br />
* Aaron Barr had to shamefully bow out of a high-profile conference where he was to give a presentation about his work in an effort to garner more money.<br />
* Information came out that HBGary and Barr were:<br />
** Spying on union organizations for the US Chamber of Commerce<br />
** Had plans to plant fake insiders within those organizations and then have them do something stupid to discredit the unions<br />
** Planned to create discrediting over-the-top 'humor pieces' on the US Chamber Watch,, the group monitoring USCoC activities.<br />
** Barr planned to release what he told was flawed information for millions of dollars, information he knew could or would get innocent people arrested.<br />
** They were working on a presentation for Bank of America who wanted Wikileaks taken down. What they were proposing was mostly illegal. It included numerous cyber-attacks, creating internal strife within the funders of Wikileaks, spreading disinformation and a concerted media campaign to smear Julian Assange. They intended to disrupt all payments to the site and make it impossible to have further submissions. <br />
** They also were in the process of creating unlicensed Windows games to release into the wild on Asian sites. These games contained backdoors from which they could launch attacks.<br />
** They planned to put pressure on civil liberties lawyers to make them fearful for their jobs and unwilling to offer more support or open criticism.<br />
** The USAF sought from HBGary software from which they could control thousands of fake online personas on social media to gather information and spread the illusion of assent with the US government among a large portion of the populace.<br />
* Final results:<br />
** Everyone distanced themselves from Barr and HBGary.<br />
** Barr resigned in disgrace<br />
** HBGary's potential company sale and work disappeared and they went under.<br />
<br />
==== Lessons Learned ====<br />
* Use tried and tested software. A custom CMS allowed the SQL injection that started this ball rolling. Anything on the web with public access should be secured in the stronges manner in every way possible<br />
* Follow best security practices: This could apply to most of these mistakes in this example. By not salting their MD5 hash, they left their user info open to attacks by Rainbow Tables which has been around since 1980 and for which software is commonly available.<br />
* Apply all the latest updates, especially security ones. If the servers had been patched for a widely known vulnerability, the attack could have been stopped.<br />
* Best password practices:<br />
** Use long passwords with both upper and lower-case characters plus numbers and non-alpha-numerical characters if possible. <br />
** NEVER use a common word or password as those are very easily broken with dictionary attacks. <br />
** NEVER reuse a password across multiple websites.<br />
** See the [http://www.labnol.org/internet/different-passwords-for-websites/17961/ Mozilla method] for password creation.<br />
* People with more power should have stronger passwords for security not weaker passwords for ease of use because they can object.<br />
* Firewall identities. Aaron Barr used the same password for many sites, including his personal social media sites, email, internal and external servers and personal iPad. [Namechk.com] makes it easy to find the reuse of usernames across sites.<br />
* Social engineering. The hardest to defend against and probably the most common hacking tools. In this case, a sense of urgency was used but they usually appeal to sexuality, greed or the human want/need to help. It is much easier to get information from a human than to hack a computer. Social engineering takes place in most hacking in some form.<br />
** [http://en.wikipedia.org/wiki/Bradley_Manning PFC Manning] incident<br />
*** Manning exfiltrated classified information and gave it to reporters and Wikileaks. Data included sensitive diplomatic cables, video of American troops killing reporters, as well as operationally secret military data. Manning used a CD-RW labeled as ''Lady Gaga'' to get the information out. Manning would simply knock on the door to the secure area and ask to listen to his CD. He would lip-sync to songs that were not playing while in actuality secrets were copied to the ''Lady Gaga'' CD.<br />
*** This was not a technical hack but a human hack. The use of technology was no more than inserting a CD and downloading information. Manning played on their trust and used acting to continue the trust.<br />
** Social engineering in email<br />
*** Phishing emails use things like fear of having your account terminated, getting in trouble for using a "bogus" credit card, fear that your bank account might have been compromised,etc.<br />
*** [http://en.wikipedia.org/wiki/Nigerian_scam Nigerian scam or 419 emails] play on your want to help or greed by telling you that you are helping some person in trouble or that you will gain large amounts of money. <br />
*** Spam emails often play on your sexuality (porn, dating), greed (Get rich quick), or fears (Viagra, Rogaine, breast enhancement, weight loss)<br />
** What Social Engineering looks like<br />
*** It doesn't and that's the point. It comes at you sideways smiling.<br />
<br />
=== Hacking Facebook ===<br />
<br />
The story: A friend and I were both interested in computer security. We were talking about hacking facebook accounts and he gave me permission to try to get into his<br />
<br />
At that time, Facebook had a web page where you could reset the password if your email associated with your Facebook account had been compromised and you could no longer access it.<br />
<br />
The form had the following fields<br />
* The email you can now be contacted at<br />
* The old email address<br />
* The full name on the account<br />
* DOB<br />
* FB web address of account<br />
<br />
I was to assume that all I knew was his full name and city he resided in.<br />
<br />
==== DIGGING ====<br />
<br />
I logged out of Facebook and cleared my cache. I logged back into the password reset page and:<br />
* Gave them my email address created just for this. In real life I would have created a throwaway account through [http://en.wikipedia.org/wiki/Proxy_server proxies].<br />
* I was able to find his email address because someone other than himself had posted it. I looked up his name and city and found a listing for a hobby group he was the leader for. Someone asked for information and a 3rd party listed his email for them.<br />
* Using the username portion of his email “username@email.com”, I was able to take the standard Facebook format for user profiles and add his username (http://www.facebook.com/username). I confirmed this was him and now had the correct web address.<br />
* I had his name to start with but was able to access available information to get a middle name and was prepared with variations on his name if I did not immediately succeed with that question.<br />
<br />
At this point, I could not get his date of birth. I looked at publicly available information as to where my friend had lived in the US. I started searching for his name in conjunction with these cities. I found a city on the east coast where he'd had another public group he was involved with. <br />
<br />
I then started looking at relatives and the places they had lived. I searched for their names and cities listed. I found a listing for his dad being involved with a volunteer organization. There was no information listed for contact. <br />
<br />
==== SOCIAL ENGINEERING ====<br />
<br />
I read a newsletter stating his involvement with a certain individual in this organization. Posing as a relative of this individual, I contacted the organization via phone and asked for his contact information. Because I knew his name and some information they probably considered private, they gave me his personal email address. I emailed him stating that I was a friend from that east coast city and knew him through that public group. I said I had a really nice gift for him but had forgotten his birthday. I was so embarrassed because we were good friends and would he please not tell my friend that I'd forgotten his birthday. The last piece of the puzzle was had.<br />
<br />
LESSONS<br />
<br />
* Firewall identities/Strategically don't re-use identities<br />
* Be careful what you put online<br />
* Insist on being behind a login for group sites<br />
* Don't reuse usernames<br />
* Social engineering – ask people to never reveal your information<br />
<br />
<br />
=== RSA Security Tokens ===<br />
[http://en.wikipedia.org/wiki/RSA_%28security_firm%29 RSA Security] owns [http://en.wikipedia.org/wiki/SecurID SecurID] which is a security token popular with government and defense companies. There is a seed number within the RSA system that, if compromised, will make those tokens useless.<br />
The attackers sent a spreadsheet out entitled “2011 Recruitment Plan” that had a 0-day Flash exploit implanted. Using these infected systems they were able to sniff traffic and find the keystore which they were able to escalate to steal them. <br />
<br />
LESSONS<br />
<br />
* [http://en.wikipedia.org/wiki/0-day_exploit 0-day] exploits and virus creation to definition cycle.<br />
* Heuristic programs<br />
* Spear-phishing/phishing<br />
* Social engineering<br />
* Use administrative accounts judiciously<br />
* Don't re-use passwords<br />
* Patch<br />
* Use 3rd part penetration testing<br />
<br />
=== Stuxnet ===<br />
[http://en.wikipedia.org/wiki/Stuxnet STUXNET] was a first, a guided missle of sorts... a worm that sought out only Siemans-made Iranian nuclear fuel centrifuges. The machines were air-gapped and so security was probably more lax than normal. The worm would lie in wait until the right times, override the alarms signalling anything being wrong and throw the centrifuges slightly off to ruin them.<br />
<br />
* USB trick and history. Curiosity and voyeurism. Social engineering<br />
* 0-day exploits for windows used<br />
* They could have stopped USB use through policy, computer and real-life<br />
<br />
<br />
OVER-ARCHING LESSONS<br />
<br />
* You must be vigilant<br />
* Learn and use best security practices<br />
* People both overestimate their own security and underestimate the abilities of others to flaunt it.<br />
* Don't do anything to piss people off and they won't have a reason to dig<br />
* EVERYONE is vulnerable<br />
* EVERYONE makes mistakes<br />
* No matter how smart you are, you can be socially engineered<br />
* Even if you are perfect, those around you are not<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=70169Computer Basics2014-03-29T17:39:36Z<p>K7aay: </p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
===Hardware longevity===<br />
<br />
All digital devices are susceptible to two problems which cause the majority of failures; overheating and [http://en.wikipedia.org/wiki/Voltage_spike voltage spikes]. A [http://en.wikipedia.org/wiki/Underwriters_Labs UL] approved [http://en.wikipedia.org/wiki/Surge_protector surge protector] with a low clamping voltage can divert surges to ground if your house or office wiring has a good ground. Ground testers are available from hardware stores to tell if your outlets are well grounded, but it's guaranteed that a surge protector cannot work if attached to an ungrounded outlet.<br />
<br />
Voltage spikes, also called power surges, can travel over power lines, phone lines, [http://en.wikipedia.org/wiki/DSL DSL] lines and [http://en.wikipedia.org/wiki/Cable_Internet_access cable] lines. <br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://upload.wikimedia.org/wikipedia/commons/1/1f/File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)].<br />
<br />
All three have common elements; a Menu button at upper or lower left, a bar at top or bottom which shows running programs, and on the right side of that bar in Windows and Linux there's an area showing the time and icons for programs which are always running. Linux and Mac OS X have a 'dock' which allows you to quickly pick the programs you run the most.<br />
<br />
It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Wine&diff=70039Wine2014-03-27T23:59:00Z<p>K7aay: /* Installing Windows Programs in wine */ updated to better comply with what we teach</p>
<hr />
<div>[http://winehq.org Wine] is a WINdows Emulator which allows a Linux user to play windows games and other programs. Free Geek Tech Support will offer help with installing or configuring wine only in [[Wine Support Policy | limited circumstances ]], but it can still be a fun and potentially useful project for the geekier minded adopter. Installing is easy from the command line (apt-get install wine) or from the Ubuntu Software Center. Each user on the system needs to configure the installation using winecfg. Programs can be installed or run by opening the exe file in wine.<br />
<br />
'''[http://appdb.winehq.org/ Wine Application Database]''': You can check to see if a specific game or program will work on wine by visiting the wine application database. If the program has already been tested by someone it should contain a page with information on how well the game runs and any notes or instructions for getting the game running properly on Linux. <br />
<br />
==Installing wine==<br />
Wine can be installed using the Ubuntu Software Center under the Ubuntu Applications menu.<br />
We recommend the stable version of Wine Ubuntu includes in its repositories (this is the only version we will support) , however might chose to use the latest version available from the official wine repositories if you are installing it yourself. Instructions for installing the latest version of wine can be found''' [http://winehq.org/download/deb here].'''<br />
<br />
==Installing Windows Programs in wine==<br />
<br />
[http://sourceforge.net/projects/winedoors/ wine-doors] is a type package manger for wine that helps assist users in installing some more common windows applications under wine. These programs include Internet Explorer 6, Steam (Half-Life 2, Portal, ect), World Of Warcraft, Windows Media Player, and many others. <br />
<br />
For applications not included in wine doors, most windows applications can be installed simply by double clicking on the executable file after wine has been installed. Wine installs programs to a virtual windows drive which can be access by going to the applications menu and selecting wine> Browse Wine Drive. If a program created a desktop icon or start menu item for windows it should be located on your ubuntu desktop and/or under the wine programs menu respectively.<br />
<br />
A simular manager is [https://apps.ubuntu.com/cat/applications/saucy/wine1.4/ Wine Windows Program Manager] which allows right-click launching of Windows apps such as [http://browsers.evolt.org/browsers/archive/ie/win32/ IE standalone installers].<br />
<br />
Some tips:<br />
<br />
*Programs on multiple cds are often easier to install if you copy all the files on to the hard drive first.<br />
*Many games require high end video cards and the binary drivers for those cards (e.g. NVidia)<br />
*If you want to install the binary drivers for your video card see this [https://help.ubuntu.com/community/BinaryDriverHowto page]<br />
*Always try to find a standalone installer instead of the popular installer which will depend on a lot of Internet access.<br />
<br />
<br />
<br />
[[Category:Tech support]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69940Leaving no trace in a digital world2014-03-07T16:22:00Z<p>K7aay: /* TAILS */</p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus solely on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government - M$/NSA makes it easier to hack you [http://j.mp/MSeasiertheft] “Purposeful backdoors in security products - another revelation from leaked security agency documents - benefit all hackers. If firms have allowed for weaknesses in their product sets, they don’t just open up holes for agents to exploit, but criminals too. Organised crime groups are pumping money into hunting for such vulnerabilities, placing the everyday user at ever greater risk.”<br />
<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It is far safer than just TOR or the Tor Browser Bundle. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* [http://j.mp/borderinspection Going through customs] – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69939Leaving no trace in a digital world2014-03-07T16:18:28Z<p>K7aay: /* Miscellaneous */</p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus solely on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government - M$/NSA makes it easier to hack you [http://j.mp/MSeasiertheft] “Purposeful backdoors in security products - another revelation from leaked security agency documents - benefit all hackers. If firms have allowed for weaknesses in their product sets, they don’t just open up holes for agents to exploit, but criminals too. Organised crime groups are pumping money into hunting for such vulnerabilities, placing the everyday user at ever greater risk.”<br />
<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* [http://j.mp/borderinspection Going through customs] – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69938Leaving no trace in a digital world2014-03-07T16:14:54Z<p>K7aay: /* Forms of snooping and how to counter each */</p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus solely on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government - M$/NSA makes it easier to hack you [http://j.mp/MSeasiertheft] “Purposeful backdoors in security products - another revelation from leaked security agency documents - benefit all hackers. If firms have allowed for weaknesses in their product sets, they don’t just open up holes for agents to exploit, but criminals too. Organised crime groups are pumping money into hunting for such vulnerabilities, placing the everyday user at ever greater risk.”<br />
<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* Going through customs – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69937Leaving no trace in a digital world2014-03-07T16:12:24Z<p>K7aay: </p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus solely on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* Going through customs – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69936Leaving no trace in a digital world2014-03-07T16:11:46Z<p>K7aay: /* Forms of snooping and how to counter each */</p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus soley on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions ('plugins') for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* Going through customs – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Leaving_no_trace_in_a_digital_world&diff=69935Leaving no trace in a digital world2014-03-07T16:11:04Z<p>K7aay: /* Forms of snooping and how to counter each */</p>
<hr />
<div>==Leaving No Trace In A Digital World==<br />
<br />
Purpose: Learn how to communicate safely, to protect your data and to 'cover your tracks' by obfuscating your identity and browsing history, online and on your computer. <br />
<br />
Because of its use within the TOR project [https://www.torproject.org/], we will focus soley on using Firefox.<br />
http://www.mozilla.org/en-US/firefox/new/<br />
<br />
This assumes the use of an Ubuntu [http://www.ubuntu.com] operating system. Most of these plugins and programs can be accessed through the Ubuntu Software Center, Synaptic Package Manager or terminal, but links will be provided when practical. While we may be able to answer questions regarding Windows-specific issues, this will not be included here.<br />
<br />
<br />
<br />
===Forms of snooping and how to counter each===<br />
<br />
Physical<br />
* Writing passwords down<br />
** Either don't do it or apply a basic, personal cryptography if you do<br />
*** A simplistic cryptography would be to make every letter and number the one above it and reverse capitalization so that the password ''HallB56'' would become ''iBMMc67''<br />
*** This is cryptography at its simplest<br />
* Using computers in view of others<br />
** Privacy filters are polarized pieces of plastic that make it where it is only possible to see your screen if you are directly in front of it<br />
** Don't type passwords or using sensitive sites that may reveal an identity in front of others<br />
* Physical keyloggers [https://en.wikipedia.org/wiki/Hardware_keylogger]<br />
** Checking the back of the machine if possible<br />
** Using another keyboard (Roll-up)<br />
** On-screen keyboard<br />
<br />
DNS/OpenDNS<br />
* Explain the Domain Name System [https://en.wikipedia.org/wiki/Domain_Name_System] and its exposure of your web use:<br />
** DNS translates sites typed in as words (ie: freegeek.org) into their actual IP addresses (ie: 67.23.3.45)<br />
** Think of it as a phone book for the internet<br />
* How it can be tracked through things like OpenDNS [https://www.opendns.com/]<br />
* Tor vs. Tor Browser Bundle (TBB) – DNS leaks [http://www.dnsleaktest.com/what-is-a-dns-leak.php]<br />
** While it is possible for your traffic to be encrypted, without proper set-up, your DNS can go in "the clear" and reveal what sites your encrypted traffic is going to<br />
** This is why the TBB is preferred over manually configuring TOR<br />
<br />
Computer Software<br />
* Malware or legitimate tracking software such as those used by companies or parents<br />
** Spyware, viruses and root kits<br />
* Temporary files / Cookies / Browser History<br />
** Instructions for clearing Firefox<br />
*** Tools -> Clear Recent History -> Time Range To Clear : Everything -> Check all for most privacy<br />
*** Add Firefox extensions for greater privacy<br />
** Not useful against keyloggers and malware<br />
* Private Browsing mode<br />
** Instructions for Private Browsing mode in Firefox<br />
*** Tools -> Start Private Browsing<br />
** Not useful against keyloggers and malware<br />
* Universal privacy setting in Ubuntu (Ubuntu 12.04)<br />
** Deleting histories globally<br />
** Setting applications and types of applications to not log<br />
** Turning logging off globally<br />
* Bleachbit<br />
** Description: BleachBit frees disk space and guards privacy by freeing your cache, deleting cookies, clearing Internet history, shredding temporary files, deleting logs, and discarding junk. It wipes clean 90 applications. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Free and open source<br />
** http://bleachbit.sourceforge.net/ OR in the terminal type:<br />
sudo apt-get install -y bleachbit<br />
<br />
Route of Communications<br />
* Router Logs (Router is #1 in traceroute example)<br />
** VPN – Virtual Private Network [https://en.wikipedia.org/wiki/Virtual_private_network]<br />
*** Privoxy/Hamachi/Proxy Switchy home VPN - http://lifehacker.com/5763170/how-to-secure-and-encrypt-your-web-browsing-on-public-networks-with-hamachi-and-privoxy<br />
*** Paid and free VPNs<br />
* Traceroute Example to show all points your traffic goes through<br />
traceroute to google.com (173.194.33.14), 30 hops max, 60 byte packets<br />
1 192.168.0.1 (192.168.0.1) 3.016 ms 3.133 ms 6.081 ms<br />
2 ptld-dsl-gw05-197.ptld.qwest.net (207.225.8x.1xx) 48.721 ms 52.120 ms 52.231 ms<br />
3 ptld-agw1.inet.qwest.net (207.225.85.33) 54.018 ms 55.723 ms 56.663 ms<br />
4 sea-edge-12.inet.qwest.net (67.14.41.26) 63.015 ms 67.598 ms 67.408 ms<br />
5 65.122.121.66 (65.122.121.66) 121.780 ms 122.806 ms 124.521 ms<br />
6 66.249.94.212 (66.249.94.212) 71.735 ms 46.955 ms 49.166 ms<br />
7 209.85.253.24 (209.85.253.24) 49.250 ms 51.107 ms 51.987 ms<br />
8 sea09s01-in-f14.1e100.net (173.194.33.14) 53.532 ms 55.166 ms 56.442 ms<br />
* ISP - your internet provider (#2-4 in traceroute example)<br />
* Backbones - infrastructure provided by large telecoms that most traffic goes through (#5-7 in traceroute example)<br />
* End Site - the web page,etc that you are visiting (#8 in traceroute example)<br />
* Government<br />
* Your traffic could be logged, recorded or inspected at any point<br />
<br />
===Firewalling Online Identities===<br />
You should keep a public identity and at least one private identity. For the public identity, it should be things you want traced back to you. It could be linked to your real name so friends can find you. If you have a business you definitely want people to be able to find you. You want to keep everything you wish to keep private contained within private accounts that can never be linked to your public accounts or real identity in any way.<br />
<br />
The basic and advanced principles of firewalling your identities are to prevent someone from linking information together about you from different sources on the web and tying your real and pseudo identities together or information you don't want out there. Here is a linking scenario.<br />
* You have a business called Example Business, Inc.<br />
* The attacker Googles ''Example Business, Inc.'' and finds your company web page<br />
* On your company web page you have a link to your business blog which is hosted on the Wordpress site at ''ebincaltaccount.wordpress.com''<br />
* The attacker Googles ''ebincaltaccount''<br />
* 5 years ago, you made an arrangement to sell something through a forum and publicly posted your phone number using ''ebincaltaccount'' as a username<br />
* Googling the phone number brings up a name and address<br />
* Searching for your name brings up personal blog posts about your family. Your facebook is not locked down so the attacker can see everything there. This is also linked to another email<br />
* Searching for that address brings up a listing on a site that logs your IP address<br />
* Running a whois on that IP address shows the attacker that it is static<br />
** A ''WHOIS'' [https://en.wikipedia.org/wiki/Whois] is a way of finding out information about an IP address or domain name<br />
** A dynamic IP addresses change from time to time and static addresses stay the same. A static address would be particularly interesting to an attacker as you would have had that same address for a while (which means it could be linked back to you) and that you have that address now (meaning they can attack that address and they know they are attacking your personal network)<br />
* Searching for that IP address returns other blog posts that link to another username<br />
* Searching for that username shows up some things you would like to never have linked back to your real identity (use your imagination)<br />
* The attacker now has your real name, address, phone number, web address, IP of your personal computer, family member's names, friend's names, multiple email addresses, multiple usernames and information you would like not to be known, etc. This all could be used against you in many forms. <br />
<br />
Linking starts with what is known and branches out in all directions with each new piece of information that can be linked back to the original information and subsequent discoveries. <br />
<br />
* Basic<br />
** Maintaining a separate email account for privacy<br />
** Maintaining non-repeating usernames<br />
** Firewalling your real vs. private identities<br />
*** Never refer to your private email or usernames from your public email or usernames and vice versa<br />
*** Never refer to you other private accounts from another private account<br />
*** Never release any real-world identifying information from private accounts such as phone number, address, name, etc.<br />
* Advanced - all the basic steps plus:<br />
** Create all emails and private user accounts through TOR, from open wireless connections, etc<br />
** Rotate connections or the appearance of different connections<br />
*** This can be accomplished by clicking "New Identity" in Vidalia<br />
** Never have any of these emails or accounts tied to any non-public IP, non-proxied or non-TOR IP address (home, work or friend's internet connections)<br />
<br />
<br />
===Tor Browser Bundle===<br />
<br />
TOR is a second-generation form of the 'onion routing' concept which was originally developed by the US Navy. Your traffic is routed through multiple computers at different places on the globe. Each computers only know the last computer that sent it traffic, not the whole route, making backtracking impossible. https://www.torproject.org/about/overview.html.en<br />
* CAVEATS:<br />
** Your traffic is encrypted from your computer, through the route of computers until the very last computer in the chain. That computer decrypts your traffic to send it to it's destination. This would make it possible for someone running a rogue TOR node to see your traffic at this point. HTTPS, VPNs or other encryption should be used within TOR for the ultimate protection.<br />
** If a person is able to watch both the traffic coming out of your computer and the traffic arriving at the end site simultaneously, they can use statistical analysis to guess what traffic is yours. This is theoretical.<br />
<br />
The Tor Browser Bundle (Portable TOR) is a version of TOR bundled with Vidalia and Firefox configured with the Tor Browser Button, HTTPS Everywhere and NoScript. It is used on an as-needed basis without installation. It comes configured for pretty good anonymity out of the box – https://www.torproject.org/projects/torbrowser.html.en<br />
* There is a possibility that adding more add-ons than listed here could compromise your anonymity<br />
* The changes to this installation are persistant<br />
* TBB Firefox vs. regular Firefox<br />
** Both can be running at the same time, one through your regular connection and one through the TOR network. Look for the Torbutton to avoid confusing the two.<br />
<br />
===TAILS===<br />
<br />
TAILS is an amnesiac LiveCD/USB that writes nothing to the hard drive. It contains TOR, Pidgin, encryption tools and more - https://tails.boum.org/index.en.html<br />
<br />
<br />
===Suggested Firefox Plugins===<br />
* Adblock plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus – Blocking ads blocks some tracking<br />
** Download EasyList and Fanboy's list.<br />
* Better Privacy - https://addons.mozilla.org/en-US/firefox/addon/betterprivacy – <br />
** Deletes LSOs (Flash Cookies). <br />
** Set to delete upon exit.<br />
* Cookie Monster - https://addons.mozilla.org/en-US/firefox/addon/cookie-monster - <br />
** Check all options but “Block All Cookies” and the ones about the dialog and icon.<br />
* Flash Block - https://addons.mozilla.org/en-US/firefox/addon/flashblock – Block ads/flash tracking<br />
** Enable and choose to block Silverlight as well<br />
* RefControl - https://addons.mozilla.org/en-US/firefox/addon/refcontrol – Changes referrer on website headers<br />
** Choose “Forge” for sites not listed<br />
* HTTPS Everywhere - https://www.eff.org/https-everywhere/ - Included in TAILS.<br />
** Make sure it is enabled and never turn this off<br />
* Noscript - https://addons.mozilla.org/en-US/firefox/addon/noscript <br />
** Choose to Forbid Scripts Globally<br />
* CAVEAT: Any extraneous applications may be able to track you<br />
<br />
===Email Encryption===<br />
Thunderbird<br />
* https://www.mozilla.org/en-US/thunderbird/<br />
<br />
GPG<br />
* http://www.gnupg.org/<br />
<br />
Enigmail plugin<br />
* http://enigmail.mozdev.org/home/index.php.html<br />
<br />
<br />
===Miscellaneous===<br />
Pidgin – IM/IRC/Skype – On TAILS with OTR <br />
* OTR plugin - http://www.cypherpunks.ca/otr/ <br />
* End to end encryption for chats <br />
* Pidgin TOR set-up<br />
** Accounts → Choose account → Proxy Tab → Use “Tor/Privacy (SOCKS5)” → Set host to 127.0.0.1 and port to 9050<br />
Disk Encryption <br />
* Ubuntu encryption on install - $HOME<br />
* LUKS - https://wiki.archlinux.org/index.php/Dm-crypt_with_LUKS <br />
** gdecrypt as GUI<br />
*** http://gdecrypt.pentabarf.de/screenshots.html<br />
* Truecrypt<br />
** http://www.truecrypt.org/downloads<br />
** http://linuxandfriends.com/2010/02/03/how-to-truecrypt-setup-on-ubuntu-linux/ <br />
* Going through customs – outer encryption vs. inner hidden encryption - plausible deniability<br />
<br />
Erasing Files<br />
* Why they are not erased<br />
* secure-delete - http://superuser.com/questions/19326/how-to-wipe-free-disk-space-in-linux/19377#19377<br />
<br />
Environment Checks<br />
* http://ip-check.info/?lang=en<br />
* http://www.cotse.com/proxycheck2.htm<br />
<br />
[https://en.wikipedia.org/wiki/Steganography Steganography]: Concealing data within an object. http://www.strangehorizons.com/2001/20011008/steganography.shtml http://www.garykessler.net/library/steganography.html<br />
<br />
https://ixquick.com/<br />
* This is a search engine that does not log searches, IP addresses or anything else. They also use no cookies.<br />
* They also offer an anonymous proxy connection on each search result [https://ixquick.com/proxy/eng/help.html]<br />
* More information here - https://ixquick.com/eng/protect-privacy.html<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69685Computer Basics2014-01-21T22:07:44Z<p>K7aay: /* Software */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://upload.wikimedia.org/wikipedia/commons/1/1f/File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)].<br />
<br />
All three have common elements; a Menu button at upper or lower left, a bar at top or bottom which shows running programs, and on the right side of that bar in Windows and Linux there's an area showing the time and icons for programs which are always running. Linux and Mac OS X have a 'dock' which allows you to quickly pick the programs you run the most.<br />
<br />
It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69684Computer Basics2014-01-21T21:50:49Z<p>K7aay: /* Operating systems */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)].<br />
<br />
All three have common elements; a Menu button at upper or lower left, a bar at top or bottom which shows running programs, and on the right side of that bar in Windows and Linux there's an area showing the time and icons for programs which are always running. Linux and Mac OS X have a 'dock' which allows you to quickly pick the programs you run the most.<br />
<br />
It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69683Computer Basics2014-01-21T21:46:10Z<p>K7aay: /* Operating systems */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux] [http://www.zimagez.com/zimage/screenshot-01212014-011708pm.php (xfce desktop)], [https://www.apple.com/osx/what-is/ Mac OS X] [http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg/800px-2010-01-21_MacBook_Pro_flat_panel_showing_Earth_background.jpg (Mac OS X desktop)], and [http://windows.microsoft.com/en-us/windows-8/meet Windows] [http://www.theeldergeek.com/windows_7/images/Installation%20Scenario%20Two/TEG-0259_small.jpg (Windows XP desktop)]. It's extremely difficult if not impossible to run a program designed for one operating system on another, with the possible exception of Windows on Linux. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69682Computer Basics2014-01-21T21:09:42Z<p>K7aay: /* Connectivity */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection to work.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69681Computer Basics2014-01-21T21:08:45Z<p>K7aay: /* Operating systems */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are three major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69680Computer Basics2014-01-21T21:08:23Z<p>K7aay: /* Operating systems */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems define a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69679Computer Basics2014-01-21T21:07:47Z<p>K7aay: /* Software */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, sub-directories/folders, files of data, and you. <br />
<br />
* A [http://commons.wikimedia.org/wiki/File:Server-directory-yellow.svg drive] is a physical or virtual device like a [http://commons.wikimedia.org/wiki/File:Wooden_file_cabinet.JPG file cabinet]<br />
** A [http://upload.wikimedia.org/wikipedia/commons/e/ef/GNU-Linux_directory_tree.png directory] is like a [http://commons.wikimedia.org/wiki/File:File_cabinet_blue.svg drawer] in that file cabinet<br />
*** Within that drawer, there are many [http://www.staples-3p.com/s7/is/image/Staples/s0445514_sc7?$grid4$ hanging folders], as there are many [http://upload.wikimedia.org/wikipedia/commons/9/92/Directory_tree.png sub-directories] beneath the top, or 'root' directory. <br />
**** Within a sub-directory, there can be one or many files which hold your data, just like a hanging folder can hold multiple paper [http://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/Folder-documents.png/120px-Folder-documents.png file folders] which hold paper pages.<br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems give a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69678Computer Basics2014-01-21T20:51:58Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster. There's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, subdirectories, folders, files of data, and you. <br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems give a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69677Computer Basics2014-01-21T15:36:08Z<p>K7aay: /* Operating systems */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, subdirectories, folders, files of data, and you. <br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems give a common set of commands for programs and programmers to use. They stand between the programs and turn what you ask the program to do into something the PC can understand; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69676Computer Basics2014-01-21T05:27:53Z<p>K7aay: </p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here, and many of them will only be discussed briefly. The student should look on this outline also as a guide to further study. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there are two very important concept to learn.<br />
<br />
1 [https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
<br />
2 Drives, directories, subdirectories, folders, files of data, and you. <br />
<br />
<br />
== Operating systems ==<br />
<br />
Operating systems give a common set of commands for programs and programmers to use. <br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69665Computer Basics2014-01-19T06:59:30Z<p>K7aay: /* What Fits Inside */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc All-in-one machines] fit the computer behind the screen. <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=all-in-one+pc#q=laptop laptop] takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=tablet tablet computer] takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=smartphone smartphone] is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the [http://www.bcot1.com/bios03.jpg BIOS], once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were [http://akh.com/akh/assets/Image/flexSDKcmd01.png monochrome] (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); [http://www.andrewault.net/wp-content/uploads/2010/02/myz802.png color ] CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69664Computer Basics2014-01-19T05:41:56Z<p>K7aay: /* Software */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-in lock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69663Computer Basics2014-01-19T05:41:15Z<p>K7aay: /* Keyboard, mouse, touch pad, pointing devices */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because the most popular pointing device, a [http://en.wikipedia.org/wiki/Mouse_(computing) mouse], is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a [http://en.wikipedia.org/wiki/Touch_pad touch pad] and/or a [http://en.wikipedia.org/wiki/Pointing_stick pointing stick] device. Tablets and very recent laptops have a [http://en.wikipedia.org/wiki/Touchscreen touch-sensitive screen] instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69662Computer Basics2014-01-19T05:37:13Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [http://en.wikipedia.org/wiki/Category_5_cable Category 5 Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69661Computer Basics2014-01-19T05:35:17Z<p>K7aay: /* CD, DVD and Blu-Ray 'optical' drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discerned difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVD-R] and the more precise [http://en.wikipedia.org/wiki/DVD+R DVD+R] discs around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD+R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69660Computer Basics2014-01-19T05:28:25Z<p>K7aay: /* CD, DVD and Blu-Ray 'optical' drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs in recording computer data, so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVDs] around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD-R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69659Computer Basics2014-01-19T05:26:55Z<p>K7aay: /* CD, DVD and Blu-Ray 'optical' drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than [http://en.wikipedia.org/wiki/CD-R CD-R] and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labels are better than Taiwanese discs, which are said to be better than Chinese discs, which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
[http://en.wikipedia.org/wiki/CD CDs] hold around 700MB; [http://en.wikipedia.org/wiki/DVD DVDs] around 4.7GB. Dual layer [http://en.wikipedia.org/wiki/DVD-R_DL DVDs] hold around 8 GB and [http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable Blu-ray discs] vary from 25 GB to 128 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69658Computer Basics2014-01-19T05:17:54Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than CD-R and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labeling are better than Taiwanese discs which are said to be better than Chinese discs which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
CDs hold around 680MB; DVDs around 4.7GB. Dual layer DVDs hold around 8GB and Blu-ray discs around 27 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles, from a South American mountain top. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69657Computer Basics2014-01-19T05:16:57Z<p>K7aay: /* What Still Doesn't Fit Inside */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than CD-R and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labeling are better than Taiwanese discs which are said to be better than Chinese discs which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
CDs hold around 680MB; DVDs around 4.7GB. Dual layer DVDs hold around 8GB and Blu-ray discs around 27 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; [https://www.google.com/search?safe=off&biw=1680&bih=910&tbm=isch&sa=1&q=SD+Card SD cards] are popular in cameras and music players, [http://upload.wikimedia.org/wikipedia/commons/a/ab/MMC-SD-miniSD-microSD-Color-Numbers-Names.gif micro SD cards] in smartphones, but the most useful size is the [https://www.google.com/search?site=&tbm=isch&source=hp&biw=1680&bih=910&q=USB+Flashdrive USB flashdrive], which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69656Computer Basics2014-01-19T05:13:06Z<p>K7aay: /* What Still Doesn't Fit Inside */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than CD-R and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labeling are better than Taiwanese discs which are said to be better than Chinese discs which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
CDs hold around 680MB; DVDs around 4.7GB. Dual layer DVDs hold around 8GB and Blu-ray discs around 27 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like [http://www.office.xerox.com/solid-ink/enus.html rectangular crayons]. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69655Computer Basics2014-01-19T05:11:36Z<p>K7aay: /* What Still Doesn't Fit Inside */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than CD-R and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labeling are better than Taiwanese discs which are said to be better than Chinese discs which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
CDs hold around 680MB; DVDs around 4.7GB. Dual layer DVDs hold around 8GB and Blu-ray discs around 27 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never were inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69654Computer Basics2014-01-19T01:11:34Z<p>K7aay: /* CD, DVD and Blu-Ray 'optical' drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
These use polycarbonate discs, 5.25 inches in diameter. CD-RW discs are less reliable than CD-R and CD+R discs; there isn't any discernable difference between CD-R and CD+R discs so use whatever your optical drive can use. Multiple Internet sources claim discs with Made In Japan labeling are better than Taiwanese discs which are said to be better than Chinese discs which are said to be better than Indian discs; Your Mileage May Vary.<br />
<br />
CDs hold around 680MB; DVDs around 4.7GB. Dual layer DVDs hold around 8GB and Blu-ray discs around 27 GB.<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69653Computer Basics2014-01-18T22:51:42Z<p>K7aay: </p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing investment as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69652Computer Basics2014-01-18T22:50:41Z<p>K7aay: /* Other connectors */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices, and the common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69651Computer Basics2014-01-18T22:50:19Z<p>K7aay: /* Other connectors */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
PCs connect to other devices. Common connectors are [https://en.wikipedia.org/wiki/Serial_port Serial 9-pin], [https://en.wikipedia.org/wiki/File:DSubminiatures.svg Serial 25-pin], [https://en.wikipedia.org/wiki/IEEE_1284 Parallel], [https://en.wikipedia.org/wiki/USB_2.0#Connectors_and_plugs USB/USB2], [https://en.wikipedia.org/wiki/USB_3.0 USB3], [https://en.wikipedia.org/wiki/IEEE_1394 Firewire/IEEE-1394], and [https://en.wikipedia.org/wiki/Thunderbolt_(interface) Thunderbolt], in order of speed. The wonderful thing about computing standards is how many standards we have.<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69650Computer Basics2014-01-18T22:42:11Z<p>K7aay: /* Monitor, screen, display */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
The original displays were monochrome (white, yellow or green) cathode ray tubes ('CRT'), similar to early TVs (but with much better resolution); color CRTs followed.<br />
<br />
Laptops didn't have the room or the battery power to run a CRT, and modern laptops use a transparent LCD screen backlit by florescent tubes or an array of LED lights.<br />
<br />
Some displays are touch sensitive and can replace or work with other pointing devices.<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69649Computer Basics2014-01-18T22:38:28Z<p>K7aay: /* Keyboard, mouse, touch pad, pointing devices */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
Pointing devices weren't needed with the first two generations of personal computers (#1 - homebuilt and #2 - storebought 8-bit) but when 16-bit computers came on the scene, they had enough (barely) power to run a Graphical User Interface, which required some kind of pointing device. Because a mouse is often inconvenient to carry with a laptop or use in limited space, laptops have other pointing devices, like a touch pad and/or a pointer. Tablets and very recent laptops have a touch-sensitive screen instead of a pointer.<br />
<br />
The feel and the placement of keys can be very important to high speed typists, and custom keyboard (and pointing devices) can be essential to folks with limited dexterity.<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69648Computer Basics2014-01-18T22:33:17Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters (330 foot) before the signal needs to be re-generated by a switch or booster, and there's special cable to use for longer runs, for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69647Computer Basics2014-01-18T22:31:46Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
The speed at which data runs requires it to be carried over a radio signal, so it's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]). <br />
<br />
Ethernet cables can run for 100 meters / 330 feet, and there's special cable to use for fire-resistance in ductwork ('plenum' cable) to prevent the fire hazard you'd get by stringing regular cable (insulated by plastic, which, after all, is frozen gasoline), or for outside and burial use. <br />
<br />
Ordinary WiFi radio signals run about half a block, sometimes longer, although special directional antennas can be used to [https://en.wikipedia.org/wiki/Long-range_Wi-Fi boost the range]. The record for WiFi is 237 miles. <br />
<br />
Bluetooth is designed for a ten meter (33 foot) range. Again, special equipment can make it work further.<br />
<br />
Cellphone companies offer data service, too, which works over 4G, 3G and 2G connections. However, that can be very spendy (more to follow).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69646Computer Basics2014-01-18T22:24:31Z<p>K7aay: /* Ethernet, WiFi, Bluetooth and cellular connections */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over [https://en.wikipedia.org/wiki/8P8C#8P8C Ethernet] wires or without ([https://en.wikipedia.org/wiki/Wi-Fi WiFi], [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] and [http://www.bbc.co.uk/news/business-14574816 cellular/3G/4G]).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69645Computer Basics2014-01-18T22:20:00Z<p>K7aay: /* Speakers and microphone */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over wires (Ethernet) or without (WiFi, Bluetooth and cellular).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the 3.5mm plug on a microphone, and the green socket is for the the 3.5mm plug on a speaker set. Some speakers, microphones and headsets use a USB connection instead, or can use a [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] wireless connection.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69644Computer Basics2014-01-18T22:16:09Z<p>K7aay: /* Speakers and microphone */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over wires (Ethernet) or without (WiFi, Bluetooth and cellular).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
These can be built into a display, laptop, all-in-one PC or tablet, but are separate devices for desktop computers. The red socket on a computer is for the microphone, and the green socket is for the speaker. Some speakers, microphones and headsets use a USB connection instead.<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69643Computer Basics2014-01-18T22:13:38Z<p>K7aay: /* Hard drives and solid state drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, built in to tablets, and can also be used to make desktop machines faster. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over wires (Ethernet) or without (WiFi, Bluetooth and cellular).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69642Computer Basics2014-01-18T22:12:52Z<p>K7aay: /* Hard drives and solid state drives */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
This is where your operating system , programs and data are stored. The [https://en.wikipedia.org/wiki/Hard_disk_drive hard drive] ('HDD') has multiple spinning platters, made with exquisite care, all sealed within the device. Moving a spinning HDD severely can damage the platters and heads, resulting in system failure and data loss. Do not open the hard drive, for once exposed to the invisible dust all around us, it will never work reliably again.<br />
<br />
[https://en.wikipedia.org/wiki/Solid-state_drive Solid state drives] ('SSD') are much faster at delivering your data and use less power, and also can't be damaged by reasonable movement while working. Therefore, they are very popular in modern laptops, and built in to tablets. They are less long-lived, and the operating system should be retuned to minimize their risk of failure. Since they are more expensive per GB than HDDs, one strategy is to put just the operating system and programs on the SSD, while the HDD has your data as well as a copy of the operating system and programs in case of failure. They can also be used to make desktop machines faster.<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over wires (Ethernet) or without (WiFi, Bluetooth and cellular).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aayhttp://wiki.freegeek.org/index.php?title=Computer_Basics&diff=69641Computer Basics2014-01-18T22:02:41Z<p>K7aay: /* BIOS, the memory which doesn't forget */</p>
<hr />
<div>'''Purpose:''' This is an elementary class on hardware fundamentals with a brief excursion into other concepts, 90 minutes in length. Not all devices, programs and concepts are introduced here. http://j.mp/computer_basics<br />
<br />
'''Overview:'''<br />
Personal computing hardware have evolved rapidly in capability and shrunk in cost and size since first introduced in the latter half of the 1970s, but the building blocks of PCs remain the same. Knowing those components and how they interact empowers computing users, by <br />
* helping them save money and make better choices when purchasing equipment and services, and <br />
* prolong the longevity of their computing systems as well as <br />
* protect their data.<br />
<br />
= Hardware =<br />
<br />
[http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-2.jpg Intel's Edison computer] using the dual-core 400MHz Intel® Quark processor with memory on board, integrated Wi-Fi and Bluetooth, [http://technabob.com/blog/wp-content/uploads/2014/01/intel-edison-sd-card-size-computer-620x477.jpg fits into an SD card] slot and is expected to sell for less than $150. Thirteen years ago, a computer with a single 400MHz processor would have required a full sized desktop, and cost $2,500. Takeaway: Computers depreciate faster than cars, and improve far faster as well, so buy as little today as you can get away with, for tomorrow's will be better/faster/cheaper.<br />
<br />
=== What Fits Inside ===<br />
<br />
Multiple components fit inside a desktop computer, the big box which sits on the floor or on a desk top. <br />
<br />
* All-in-one machines fit the computer behind the screen. <br />
<br />
* The laptop takes it further, integrating the screen, microphone (sometimes), speakers, and mouse (replacing the latter with a touch pad and/or touch pointer). <br />
<br />
* The tablet computer takes it further still by dispensing with the keyboard and mouse, instead having you tap on the screen to type and swipe across the screen for what a mouse or touchpad would do.<br />
<br />
* A smartphone is a tablet with a smaller screen, plus a cellular phone built in.<br />
<br />
Now, let's review those parts.<br />
<br />
==== Power supply ====<br />
Converts wall power, which is 120 volts AC (Alternating Current), to both 5 volts DC (Direct Current) which is what chips use, and 12 volts DC, which is what motors in spinning drives and fans use. The fans are needed because devices which use a lot of power make a lot of heat, and that heat has to be moved outside the computer with fans to prevent the parts burning out. <br />
<br />
'''Do Not Open the power supply''' until you have unplugged it AND removed it from the computer AND let it sit for 24 hours. Capacitors inside the power supply enclosure can pack a hefty punch, '''even fatal for some folks'''.<br />
<br />
Laptop power supplies convert wall power to something between 12 to 20 volts DC, to charge the laptop battery; the laptop breaks that current down to 5 and 12 volts DC inside the laptop. There's no standard voltage for laptops, and no standard power plug, either, so there are a lot of leftover power supplies from broken laptops for sale on [http://www.ebay.com/sch/items/?_nkw=laptop+power+supplies eBay]. Independent manufacturers also make 'universal' power supplies for laptops where you can buy one power supply with several adapters, and then use the adapter which fits your laptop.<br />
<br />
==== CPU, the central chip ====<br />
<br />
The speed of the [https://en.wikipedia.org/wiki/Central_processing_unit Central Processing Unit] or CPU chip is now measured in GHz, [https://en.wikipedia.org/wiki/Hertz gigahertz], billions of steps per second. Older machines' speed was measured in MHz or [https://en.wikipedia.org/wiki/Hertz megahertz]). That doesn't mean an older machine is useless, and huge amount of work was done on megahertz machines such as the [https://en.wikipedia.org/wiki/Apple_II Apple II] and the [https://en.wikipedia.org/wiki/Kaypro Kaypro 10], for the CPU has less impact on your computer's speed than many other components. You can, however, use the CPU speed as a very rough guide to the age of a machine. <br />
<br />
Same-generation [https://en.wikipedia.org/wiki/X86 x86] CPUs made by Intel, AMD, VIA, et al. are roughly equivalent if they have the same speed; [https://en.wikipedia.org/wiki/ARM_architecture ARM] chips are not as powerful for the same speed and the version number (shown as v6, v7, v8, et al., newer versions having higher numbers) is a more important indicator of power than the speed.<br />
<br />
Macs now use 64-bit x86 CPUs, as do PCs sold with Microsoft Windows. Linux, however, can run on ARM CPUs as well as [https://en.wikipedia.org/wiki/IA-32 32-bit] and [https://en.wikipedia.org/wiki/X86-64 64-bit] x86 CPUs.<br />
<br />
==== GPU, the chips which make the screen work ====<br />
<br />
As PCs grew more powerful, they were used for more than games and office work. However, high resolution graphics requires more and more powerful graphics chips, or Graphics Processing Units. The best GPUs are found on plug-in cards, and generally have their own fans, in addition to the fans of the power supply and the CPU. Some laptops now have two graphics cards, a lesser one for normal use and a greater one for graphics and gaming. Desktop machines can have multiple GPU cards tied together for even more speed. You can mix and match multiple types of displays if you want multiple screens, provided the display adapter(s) permit.<br />
<br />
Graphics adapters nowadays have three major kinds of sockets; [https://en.wikipedia.org/wiki/HDMI HDMI] (same as your digital TV), [https://en.wikipedia.org/wiki/Digital_visual_interface DVI] (for a digital monitor) and [https://en.wikipedia.org/wiki/VGA_connector VGA] (for an analog monitor). Another connector, the [https://en.wikipedia.org/wiki/DisplayPort DisplayPort], is becoming popular.<br />
<br />
==== RAM, the memory that forgets ====<br />
<br />
This is an array of very fast memory chips which is the working memory of your computer. Think of it as the size of your desktop; you can work on more different things if you have a bigger desk top (or more memory).<br />
<br />
When the computer is turned off, loses power, or reboots, the contents of memory are lost.<br />
<br />
==== BIOS, the memory which doesn't forget ====<br />
<br />
A different kind of memory is used to permanently remember what parts are in your computer, so when it is turned on, they don't have to be rediscovered every time. This is called the [https://en.wikipedia.org/wiki/BIOS BIOS], or the Basic Input Output System. <br />
<br />
The settings of the BIOS, once set up when assembled, rarely need changing, and making changes to the BIOS are not recommended for beginners.<br />
<br />
==== Hard drives and solid state drives ====<br />
<br />
==== CD, DVD and Blu-Ray 'optical' drives ====<br />
<br />
==== Ethernet, WiFi, Bluetooth and cellular connections ====<br />
<br />
It's all radio, either over wires (Ethernet) or without (WiFi, Bluetooth and cellular).<br />
<br />
==== Keyboard, mouse, touch pad, pointing devices ====<br />
<br />
==== Speakers and microphone ====<br />
<br />
==== Monitor, screen, display ====<br />
<br />
* a<br />
** a (1)<br />
* b<br />
* c<br />
* d<br />
* e<br />
* f<br />
* g<br />
** g (1)<br />
*** g (1) (a)<br />
*** g (1) (b)<br />
<br />
==== Other connectors ====<br />
<br />
Serial, Parallel, USB, USB2, USB3, Firewire/IEEE-1394, Thunderbolt<br />
<br />
=== What Still Doesn't Fit Inside ===<br />
<br />
* Printers and scanners have rarely been added inside a laptop, and never inside a desktop. Nowadays, if you want to print, either you get an all-in-one device which does the work of a printer and scanner, or if you have no need for scanning, you can get just a printer.<br />
<br />
** Printers can be black ink only, or more spendy printers print in color. The least spendy printers are ink jet printers, but those manufacturers often make up for it with expensive ink. If you will print a lot, laser printers may be less expensive in the long run, even though they are more complex. <br />
<br />
** Less frequently seen are solid ink printers; only Xerox made those, with the ink appearing like rectangular crayons. Photo printers sometimes include the dyes which make the colors in the paper, which is also pretty spendy. <br />
<br />
* If you are going to scan multiple pages in a batch, a scanner with an automatic sheet feeder is very nice. If you're just working with photos, a flatbed scanner is OK.<br />
<br />
* Flash memory drives come in many shapes and sizes; SD cards are popular in cameras and music players, micro SD cards in smartphones, but the most useful size is the USB flashdrive, which offers the most storage per buck of any flashdrive, and can be used to not only back up your system data but also install Linux. <br />
<br />
* The surge protector must be outside the computer in order to work, otherwise the surge would still be inside the case to damage the components of the computer.<br />
<br />
Then, the internet connection parts:<br />
<br />
* the 'modem' (actually a misnomer, since we're all digital now and modems were for analog phone lines, but everyone still calls it a 'modem')<br />
<br />
* the router or switch which takes one data line from the 'modem' and shares it between multiple computers<br />
<br />
* the WiFi Access Point, which is almost always packaged up with the router to make a WiFi Router, or packaged up with the router and 'modem' to make a WiFi Gateway.<br />
<br />
-<br />
<br />
And cables? Yep, you've got cables all over the place, unless you have a laptop, and there's still a power cable for that. Never pay more than the cost of a basic cable; spendy gold-plated cables work no better than regular cables. Also, don't tie up cables with plastic ties, or bundle them up tightly; loose big loops and coils won't damage your cables but tight, small bundles will.<br />
<br />
= Software =<br />
<br />
Without software, a computer is a dumb box that sits there and burns electricity, a very expensive space heater. Let's touch briefly on software, but before we do, there's a very important concept to learn.<br />
<br />
[https://en.wikipedia.org/wiki/Open_source_software Open Source Software] is software which is documented. Anyone can download the [https://en.wikipedia.org/wiki/Source_code source code] used by programmers to create it, and can use some or all of that source code to make their own programs without charge. Because its source code is freely visible, every function of the program is laid bare to detailed inspection, and its functioning is open and transparent. By contrast, [https://en.wikipedia.org/wiki/Proprietary_software closed source] or proprietary software is not subject to scrutiny, and can therefore do things people don't know about. It also tends to [https://en.wikipedia.org/wiki/Vendor_lock-inlock users in] to buying that software in the future.<br />
<br />
Open source software is almost always free, although support can be charged for. <br />
<br />
== Operating systems ==<br />
<br />
There are major families of operating systems for PCs: [https://www.linux.com/learn Linux], [https://www.apple.com/osx/what-is/ Mac OS X], and [http://windows.microsoft.com/en-us/windows-8/meet Windows]. It's extremely difficult if not impossible to run a program designed for one operating system on another; think of the operating system ('OS') as the foundation that a building rests on. <br />
<br />
It may be of interest to know that the ministry of the UK Government which is responsible for communications and security has recently declared Linux as the [http://www.techrepublic.com/blog/linux-and-open-source/linux-the-clear-choice-for-security most secure PC operating system]. Or not.<br />
<br />
Linux is open source; Mac OS X has some open source components but is closed source; Windows is closed source.<br />
<br />
== Office productivity ==<br />
<br />
Word processing, spreadsheets, databases, slide shows, and other business software. Microsoft Office is the leading such program, followed by [https://www.libreoffice.org/ Libre Office] and [https://en.wikipedia.org/wiki/Apache_OpenOffice Apache Open Office], among others.<br />
<br />
== Drawing, composing ==<br />
<br />
[https://www.adobe.com/products/photoshopfamily.html Adobe Photoshop] is well known, as is [http://www.gimp.org/features/ THE GIMP]. Those can modify photos or make entirely new pictures, but they have limitations for they only work as 'bitmap' programs. Professional drawing programs like the commercial program [https://en.wikipedia.org/wiki/AutoCAD Autocad] and the open source program [https://en.wikipedia.org/wiki/Inkscape Inkscape] are 'vector' drawing programs allow much more detailed and efficient manipulation of things within the drawing canvas<br />
<br />
== Multimedia ==<br />
<br />
Programs to play, compose, and edit music and video fall into this category.<br />
<br />
== Games ==<br />
<br />
1,298 games are listed as available from the Synaptic Package Manager of Linux. More are available for sale.<br />
<br />
== Connectivity ==<br />
<br />
Email, chat, browsers, instant messaging, other internet services all need a connection.<br />
<br />
== SAAS (Software as a Service) ==<br />
<br />
All of the above programs are now available through your web browser, when you connect through the Internet to 'server' computers which run these programs. Examples are<br />
* Gmail, Hotmail, Yahoo! Mail instead of an email client<br />
* Google Docs, Google Apps and Office 365 instead of an office suite<br />
<br />
Often those are 'free'; you provide information about yourself to the service providers when you register, and then they track where you go on the Internet. This data gets 'aggregated' (bunched together) and sold to advertisers, research firms and other companies.<br />
<br />
If you don't pay outright for a service on the Internet, you 'pay' this way.<br />
<br />
= Data =<br />
<br />
Anything you type, draw, record, make, or download to keep, is your data, and it's pretty much why you have a computer in the first place. If you don't create it, you need to get it on CDs, DVDs or from the Internet. <br />
<br />
You can back up to a local device, such as <br />
* CDR discs,<br />
* DVDR discs,<br />
* hard drives, or <br />
* USB or other kinds of flash drives. <br />
<br />
Anything mechanical or electronic will fail, sooner or later. Your backup plan should give you the ability to restore your system as well as duplicate your data so if your system fails, is stolen or destroyed, you can restore it without loss. The simplest backup is to <br />
* open the file manager<br />
* Select View from the Menu Bar at top, then check Show Hidden Files<br />
* right-click on the Home folder<br />
* open the target, the destination drive to receive the backup<br />
* click on Paste in the Menu Bar at top<br />
* When it finishes, close the file manager window <br />
* right-click on the drive which received the backup, and select Safely Remove<br />
* put the backup drive in a safety deposit box or somewhere safe.<br />
<br />
You can also copy it over the Internet to a backup or cloud service, like <br />
* [https://one.ubuntu.com/ Ubuntu One],<br />
* [https://en.wikipedia.org/wiki/Google_Drive Google Drive],<br />
* [https://en.wikipedia.org/wiki/MEGA MEGA],<br />
* [https://en.wikipedia.org/wiki/Dropbox_%28service%29 Dropbox],<br />
* [https://en.wikipedia.org/wiki/SkyDrive Microsoft SkyDrive], et al.<br />
<br />
However, if your data should remain private, [https://en.wikipedia.org/wiki/Encryption_software encrypt] it strongly first. [http://www.aescrypt.com/ AESCrypt] is an Open Source file encryption app you could use for that purpose, as are [http://sourceforge.net/projects/encrypt/?source=directory encrypt], [http://sourceforge.net/projects/ohcrypt/?source=directory OhCrypt], and [http://simplefilecrypt.sourceforge.net/ SimpleCrypt].<br />
<br />
= Internet =<br />
<br />
Internet Service Providers (ISPs) bring you a connection to and from the Internet, which is essential for email, web browsing and other data services such as on-line backup.<br />
<br />
== DSL ==<br />
<br />
DSL is provided by telephone companies, who put radio signals over the phone lines. Since telephone companies are better regulated than cable and wireless companies, it's easier to get a DSL connection to an ISP different than the phone company.<br />
<br />
The further you are from the telephone company central office, the more difficult it is to keep those radio signals clean and free from interference, and since phone lines are not laid down as the crow flies, it can be difficult sometimes to get a good DSL connection, and DSL connections are rarely as fast as cable or fiber optic, though they do tend to be better than commercial wireless ISP connections.<br />
<br />
On the other hand, DSL doesn't vary its speed like cable and wireless can. Cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely. Wireless connections also drop in speed when more users near you go on line.<br />
<br />
== Fiber Optic ==<br />
<br />
Tiny strands of glass carry far more data than cables, wires or wireless. Fiber optic data service is the ultimate kind of connection when available, and costs it. However, it's not as widespread as cable or DSL service.<br />
<br />
== Cable modem == <br />
<br />
The same cable system used for TV also carries internet data. However, cable modem systems share the cable with many of your neighbors, so when everyone gets on line, your speed dips, sometimes severely when all the gamers jump off the school bus and get on line.<br />
<br />
== Wireless (cellular) ==<br />
<br />
Modern cellular companies turn voice into data, to get more users talking over the same amount of frequencies. This inspired them to offer data service to computer users. The service can be irregular as well as spendy, but since it's sold like cellular service is, prepaid data plans often are the only kind of data service folks with marginal credit can get. Cellular wireless also serves those who have no better options.<br />
<br />
== Wireless (commercial) ==<br />
<br />
Sometimes called a WISP (Wireless Internet Service Provider), this requires a small antenna on the side of your house pointed at the tower used by the WISP. [http://www.coho.net/high_speed_wireless_isp.php Coho.net] offers service to rural communities on the west side. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Satellite service ==<br />
<br />
If you have a clear view of the sky to the south-southeast, you have have satellite TV, and satellite TV providers also offer internet data service. However, the time it takes for a signal to get from your disk to high orbit, bounce down, connect to the Internet, and then return in the opposite direction makes Internet gaming impossible. Internet phone and two-way video service is also sub-optimal. Fog, heavy rain and sleet will make the microwave signals which carry the data fade and disconnect you now and then.<br />
<br />
== Shared connection ==<br />
<br />
If your neighbor has Internet, you could ask to share their connection, either by WiFi or an Ethernet cable. However, if they wanted to, they could install software on their system to see what you were doing, including your passwords. Security, security, security!<br />
<br />
= SUMMARY =<br />
<br />
* Keep your guard up! Malware is the number one cause of data loss in the Pacific Northwest. <br />
** Never install software from an unknown source.<br />
** Never open email with data attached in email clients (e.g., [http://www.techrepublic.com/blog/linux-and-open-source/claws-mail-what-an-email-client-should-be-like/780/#. Claws], [https://en.wikipedia.org/wiki/Evolution_(software) Evolution], [https://en.wikipedia.org/wiki/Mozilla_Thunderbird Thunderbird], et al.) on your PC.<br />
** Use protection in your Firefox web browser: [https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/ AdBlock Edge] or [https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ AdBlock Plus], [https://addons.mozilla.org/en-US/firefox/addon/betterprivacy Better Privacy], [https://addons.mozilla.org/en-US/firefox/addon/ghostery/ Ghostery], [https://addons.mozilla.org/en-US/firefox/addon/noscript/ NoScript], [https://addons.mozilla.org/en-US/firefox/addon/self-destructing-cookies Self-Destructing Cookies], [https://addons.mozilla.org/en-US/firefox/addon/fbdc Facebook Disconnect], [https://addons.mozilla.org/en-US/firefox/addon/gdc Google Disconnect] and [https://addons.mozilla.org/en-US/firefox/addon/twdc Twitter Disconnect], and [https://addons.mozilla.org/en-US/firefox/addon/wot-safe-browsing-tool/ Web of Trust] are some of today's protective add-on extensions to Firefox. https://addons.mozilla.org/en-US/firefox/extensions/privacy-security lists more. <br />
* Keep your computer clean. The number two cause of PC failure in the NW is dust and animal hair buildup inside, which blocks cooling and leads to overheating, heat damage, and burnt out components. If you smoke (your choice), clean it more often because the tar in smoke will cause dust, air, and fur to stick ''tenaciously'' and cause problems sooner. This does not apply to vaping.<br />
* The number three cause of failure is caused by electrical power problems; surges, spikes, and lightning strikes. A lot of little surges and spikes can equal the damage of one large lightning strike; the damage is cumulative, and when a machine 'just stops working', it has failed as a result of those over-voltages. Look for surge protectors who offer damage coverage on systems they protect, and fill in the little card which registers your system. Adequate surge protectors have a UL 1449 standard Let Through Voltage Rating of no more than 330v, and protectors which advertise lower maximum Let Through Voltage Ratings (like the [http://www.apc.com/resource/include/techspec_index.cfm?base_sku=NET7 APC Net] series) are even better protection.<br />
* The fourth cause of failure is also caused by electrical power problems; blackouts and brownouts. A battery backup is a good idea for desktop computers and an essential for network servers.<br />
* Back up your computer frequently. If you don't protect it, then the inevitable electrical, [http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows-inside-next-gen-filesystems/ electronic] or mechanical problem will lose it for you. <br />
<br />
<br />
[[Category: Classes]]<br />
[[Category: Current Classes]]</div>K7aay