User:Tonyr/Journal/Jan07

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4jan07

Audio Skipping
iMacs/PowerMacs with CPU speeds less that 450MHz seem to have problems playing CDs using SoundJuicer and RythmBox, the CD ripper and CD player installed with Ubuntu. Playback audio will 'skip', producing gaps of a few seconds, and may even cease altogether. Loren has been able to solve this by replacing CD drives in slot loading iMacs and PowerMac Towers. I have solved it by installing gxine and manipulating its configuration parameters, specifically the increasing the number of buffer blocks and increasing the value of media.audio_cd.drive_slowdown in the xine configuration. The xine configuration file usually shows up in the users home directory as .xine/xine_config. gxine provides access to most of the configuration parameters through Preferences in its menu. There are several levels of parameter control in Preferences. The level named Master of the Universe allows a the most access. I have been increasing the slowdown parameter from 4 to 12, and increasing the number of buffer blocks from 230 to 500. Both of those were guesses on my part. Increasing the number of buffer blocks may not be necessary.

I don't know exactly why either of the solutions works. Some of the CD drives Loren has been using as replacements are much newer drives, and probably offer better performance features. The fact that there appears to be a configuration solution makes me think that the existing CD drives are not bad, but have lower performance that needs help in software. There are several different models of CD drive use in the iMacs

There are several problems with the gxine solution with the lower CPU speed Macs (233-400MHz). gxine has a visualization feature that competes with audio for CPU cycles. Turning the visualization off reduces or eliminates the 'skip' problem. Visualzation control is under the View drop down menu, but changes there do not persist across gxine restarts. I haven't found a way to make the visualization change permanent.

5jan07

iMac G4/700 Flat Panel
It's that half-basketball-long-neck thing with the flat-panel display on the top of the neck. It came in on 29Dec06. 70MHz PPC, 40G hard drive, 256 MB, DVD/CD. Runs Mac OS X just fine, but refused to boot the Ubuntu 6.10 installation CD. Yesterday and today Loren swapped out the hard drive for a wiped drive from the store. He also (miraculously) found a 256MB SODIMM to upgrade it's memory, with the goal of creating a very nice high end PPC machine.

It turns out this is a very weird machine, even for an iMac. The system memory is a SDRAM DIMM (regular PC memory). The expansion memory is SODIMM (laptop style). The expansion memory and wireless network card (airport) are underneath the bottom cover plate, which is easily removed. The drives and system memory are underneath a second bottom plate below the first one, and is much harder to remove and requires application of thermal paste to a thermal transfer plate when re-attaching it. The graphics controller is an nVidia GeForce 2 400 MX, which the Ubuntu PPC install CD apparently doesn't know how to deal with. The CD starts to boot normally, gets to the part that says loading ramdisk and then hangs indefinitely.

This version of the iMac was not in production very long. I'm thinking we won't see very many of them, and should probably not spend a lot of resource trying to solve this. It's more of a 'special project'. There may be a way to solve it, but it might involve detailed knowledge of the Ubuntu PPC boot process and maybe even some knowledge about how to manipulate OpenFirmware.

As is mentioned below in Deviant ATI video controller, there are some G4 Towers that also use nVidia controllers. It will be interesting to see how Ubuntu installation goes on those machines, should we ever get any.


The Cube
The pre-cursor to the Mac Mini. The monitor is separate, and the video connector on the Cube is a special Apple type called ADC that combines USB, power and DVI. There are three Cubes in limbo in the Mac triage area. The newest arrived yesterday, and came with an almost complete package: the Cube, Apple Studio Display 15in (LCD/ADC), power adapter, speakers, keyboard, ADC to VGA adapter (no mouse). I found a few similar packages on ebay for $400-$500. The speakers are USB. There is no hardware audio controller. I'm not certain that there is an internal speaker. I never heard a power-on chime. The standard Ubuntu installation sure would like to see some audio hardware. There is support for USB audio in Linux, but taking advantage of it does not seem to be straightforward. A Google search turned up one article that suggested installing xmms and using its Preferences to select the USB speakers. I did that, but the speakers still didn't work. USB audio can probably be made to work, but I think it is another 'special project'


Macs That Resist Ubuntu Installation
The G4/700 iMac and The Cube raise the question of what to do with nice iMac systems that require undiscovered contortions to get Ubuntu to install with incomplete functionality, or not at all. The two obvious suggestions are 1) let MacRenewal have then, and 2) sell them in the store at a discount with labeling that indicates no OS or missing functionality. A third possibility is to keep them in limbo in hopes (that Saint Nicholas soon would appear, but I digress) that there might be resource at some point to explore for solutions.


Deviant ATI video controller
Almost all of the iMac machines use ATI controllers. The half-basketball machine mentioned earlier and some higher end G4 PowerMac Towers use nVidia controllers. Other High end G4 Towers use Radeon controllers (which are also ATI, I believe). The older iMacs use ATI Rage controllers. There are many, many variations of the ATI Rage contoller. The list can be found in the log file produced when the Ubuntu desktop start up, /var/log/Xorg.0.log. All of the iMacs I have worked on so far have installed Ubuntu with working video, with the exception of the one I worked on today. This was a 500MHZ 'bubble' iMac. The video controller was an ATI Rage 128 Pro Ultra TR. After installation, Ubuntu was extremely sluggish, and any event (mouse, keyboard) that required video reaction would produce a hang of many seconds, on the order of 30-60. The best way I could find to solve this problem was to remove the glx module from the xorg startup configuration. I did it by running dpkg-reconfigure xserver-xorg and unchecking the glx module when it asked which modules to include. Removing the glx module takes away the high performance features of the controller, but does allow reasonable behavior under normal circumstances.

Moral: Watch out for the ATI Rage 128 Pro Ultra video controller!


6jan07

I'm still thinking about the Triage/Eval/Rebuild flow. I decided to write down a step-by-step of what I do at that Mac rebuild bench. It still doesn't cover everything, and a lot of detail is missing, but it's not bad. I will probably incorporate it into the diagrams somehow.

What do I really do with Macs right now?
The definitions of triage and build are different for Macs. Triage is mainly separation of received Apple equipment into FreeGeek stuff, MacRenewal stuff, and FreeGeek recycle stuff. Mac Rebuild is really a combination of Eval and Build, with the result being either resale-system or mine-and-recycle.

  1. Examine the case for damage
    • major case damage is a straight mining/recycle sign.
  2. Open it up, examine logic board for damage, blown caps.
    • Damage might be fixed by replacement, but may also indicate mining/recycle.
  3. Remove HD and memory, send them to eval for collection/testing.
  4. Remove and test the battery.
  5. Replace memory, HD, and battery if necessary.
    • If replacing battery, reset PMU. Memory should be 256MB, HD should be 10-15GB. If 256MB is not available, consider 192MB and Xubuntu installation. If 192MB is not available, don't install anything, wait for memory (or else deconstruct and return to MacRenewal Pile?)
  6. Close it up.
  7. Connect power, kbd and mouse.
  8. Power it up, boot to OpenFirmware (Command+Option+O+F).
    • If OpenFirmware is not reachable, remove power, open up the box, remove battery, leave it for 15min to half-hour. Press PMU for 5sec, press power for 5sec, replace battery, close it up, power-up with PRAM reset Command+Option+P+R, wait three chimes). Let boot proceed as far as it will. Power down, try OpenFirmware again. Record OpenFirmware version.
    • Another reported way to get to OpenFirmware in this situation (bypassing the security settings) is to change the amount of RAM by adding or removing some, then boot and reset PRAM by pressing Apple+Option+P+R and wait for three chimes. [This one worked on a G4/450 tower on 16aug07 - tr]
  9. Insert Finnix CD, note if insert mechanics seem sluggish. Boot Finnix CD from OF with 'boot cd:,\\yaboot', or power-cycle and boot CD by pressing C key right after power up and holding till bright white screen (white screen after dim white screen).
  10. Observe memory size and CPU speed from finnix boot messages. Record those.
  11. Display HD type and CD (DVD) type. hda is hard drive, hdb is CD.
    • cat /proc/ide/hda/model
    • cat /proc/ide/hda/capacity
    • cat /proc/ide/hdb/model
  12. Record HD and CD(DVD) info.
  13. Use 'lspci' to to display video controller model. The appropriate line will have 'VGA' in it. Record that.
  14. Set hardware (CMOS) clock to current UTC (GMT) time
    • date -u MMDDHHSSCCYY
    • clock -uw
  15. Shutdown with shutdown -h now. CD should be ejected; observe if ejection is sluggish.
  16. If insertion and/or ejection is sluggish, CD(DVD) drive is a candidate for replacement. This depends on availability. Replace if possible with a newer model. Do not replace with CR-1750 (oldest known slot loader).
  17. Install Ubuntu-ppc (or Xubuntu if memory is 192MB). Machine will eject CD and reboot when done.
  18. If video controller is ATI Rage 128 Pro Ultra, Ubuntu boot might be really slow, mouse and keyboard unresponsive. Drop to CLI terminal with CTL+ALT+F1 (you may have to wait for it, due to slow operation) and remove glx module from xorg configuration, either with dpkg-reconfigure xserver-xorg or by editting /etc/X11/xorg.conf directly. (need explicit step-by-step here for restarting the desktop)
  19. Update software using Synaptic Package manager.
  20. Test sound. Slower machines with older CD drives may exhibit 'skipping' behavior. Two possible solutions: replace CD drive with a newer one, or install gxine and set media.audio_cd.slowdown parameter to 12, and increase buffer count. Probably choose replacement first; choose gxine if replacement is not available.
  21. Wipe down case and screen; clean keyboard and mouse if necessary. Choose a 3-button or 2-button USB mouse if available, else use a standard Apple 1-button mouse.
  22. Fill out green configuration sheet, note any blemishes or other exceptions, set the price, tape form to case, attach a power cord. Take the bundle to the store. (need some suggested pricing guidelines here; Loren's pricing instinct is good, Macs in the store are selling, and his suggestions should be used to set up a pricing schedule as a guide.)


This procedure does not address failure of the system to power-up. Such a failure could be due to physical power supply problems or PRAM problems. Testing the power supply is currently beyond the scope of Mac Triage/Eval/Rebuild. Resetting the PRAM is described in sthe step about OpenFirmeware. There may need ot be some reorganization.

7jan07

Sometimes iMacs come in with OS X installed with high security settings. OS X usually requires a user login with password, which of course is not known. There might also be another level of security at the OpenFirmware level, implemented as an OpenFirmware password. This is similar to the BIOS admin password that is sometimes present in x86 (PC) machines. It is also possible to set parameters in OpenFirmware that lock out the keyboard, and /or restrict which drives can be used as boot devices. In some cases there is another layer of security implemented by a third party software package that sits between OpenFirmware and OS X, with it's own password protection.

The OpenFirmware password feature is only available, I think, with versions of OpenFirmware starting with 4. Installation of OS X requires, I believe, a firmware upgrade to some 4+ version.

Without the OpenFirmware password feature, Mac OS X login supposedly can be defeated by booting into single-user mode at power-up with the Command+S keyboard combination. The object for Freegeek MacBuild is really to be able to boot an install or rescue CD. If the keyboard is locked out at the firmware level, the only way I know at this point to defeat the protection is to completely drain the logic board of any residual charge and press the PMU button, which does something to the PRAM that resets it (if I understand the procedure correctly). The steps are described in the step-by-step in 6jan07 under item 8.

11jan07

B&W Ge Tower, SCSI drives, OSX/OF Security
Worked on a G3 B&W Tower today. It had OSX 10.3.3 installed with high security (kbd lockout). I defeated it by reinstalling OS X (10.0) and resetting the CUDA/PMU. This model has two buttons that look like the CUDA/PMU button, near the battery and PCI slots. I think the left one (me facing the front of the box with the side panel open) is the Power button and the right one is the PMU/CUDA. I'm not sure what the Power button does. The bit about installing Mac OSX might not be necessary. Before pushing the PMU/CUDA button, I removed and replaced the PRAM battery. A good PRAM/NVRAM references is here.

This particular box is one of the earliest B&W Towers, and uses SCSI drives. It has an Adaptec AHA-2940 controller (I think). The instructions for removing the SCSI drives are here. There are 2 SCSI drives, a 9GB (the original, I believe), and an additional 4GB drive. Dave found a pair of 18GB drives to replace them with.

The information about defeating security should go in the Triage/Rebuild graph. It's included in my step-by-step description as item 8 in the 6jan07 entry.

12jan07

There are actually two G3 B&W Towers on the work bench. The second one is more conventional, with a single IDE hard drive. The video controllers in the two boxen are the same: ATI Rage 128 RE/SG (PCI). I got as far as installing Ubuntu on the IDE box, but the installation would hang at random places, hang so bad that keyboard and mouse events were ignored. I remembered that this IDE box had not powered up at first, and since I had to install memory (there was none in it) the only other thing to reseat was the video card, so I had done that. Because of that I suspected that the video card might be involved. I swapped the video cards between the IDE box and the SCSI box. The hang symptom disappeared from the IDE box, and the installation and sale prep were successfully completed. Not surprisingly, the hang symptom appeared in the SCSI box. In addition, Ubuntu installation on the SCSI box reported many many package retrieval failures (CD read failures). That particular Ubuntu CD has been used many times with no problems. That is not to say that the CD is not damaged; it could be, and I will need to check that.

A more hopeful assumption is that the video card is really screwed up and causing lots o' problems. In order to test that, I would need another video card, the same kind. As far as I know, that means taking one out of another G3 B&W Tower. That Tower would become either a zombie, waiting around for a spare video card to turn up, or a mining source.

19jan07

The flaky video g3/tower went on the "wait-shelf". The other one went to the store. Several things go on the "wait-shelf". Right now there are systems that are "in the queue", systems that are waiting for parts, systems that have been partially cannibalized, and systems that have problems that we would like to solve. I'm using quotes in some places because none of these things are formalized, and I'm making up names as I go along. Systems "in the queue" are candidates that have not been evaluated yet.

I looked at a couple of G4 Towers that are on the "wait-shelf". Loren had done a preliminary triage on them. One is a 1GHz dual processor system, and the other is an 867MHz dual processor system. One of the processors in the 867 system (both processors are on one board) appears to be fried, and the system will not power up. The 1GHz system also does not power up, but the fans start up. I think the hard drive spins up, too, although I'm not certain about that. So what should we do about these systems?

The 867 with the fried processor is not recoverable without a replacement processor board. We can keep it for awhile and hope that a replacement shoes up. We could mine it for battery/memory/hard-drive and put it back in the Mac Pile for MacRenewal to take away. We could mine it and recycle it locally. Towers can be dismantled and recycled since they have no integrated display.

The issue of whether or not we recycle any Towers should be discussed with MacRenewal. Do they want mined systems?

Since this is the process definition stage, we should be making decisions about what kind of problems can be solved and what cannot. Systems with problems that cannot be easily solved should be cycled out, either by returning them ot the MacPile or recycling them locally. I guess that is part of the established eval/triage phase.

23jan07

Macs that Resist Ubuntu Installation, Revisited (see 5jan07)
The G4/700 Flast Panel half-dome CD boot problem is apparently a weakness in the Dapper and Edgy installation CDs. Both Breezy (5.10) and Feisty (7.04 alpha) installation CDs boot in the G4/700 just fine. The Breezy CD uses a less than perfect video interface, but it works. The Feisty CD apparently solves the video problem for nVidia controllers; unfortunately, it seems to have forgotten how to handle ATI controllers in G3 machines. It boots in a G3 'bubble' iMac (at least it gets to the login sound report) but without video.

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