Tonys Mac Journal

4jan07
I'm going to try to record my experience working with the Macs at FreeGeek. This will be mostly subjective train of thought, first impressions, immediate reactions, that sort of thing. This first few entries will be a recap of the things I can remember from that past couple of weeks.

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 acces 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 incrreasing the number of buffer blocks from 230 to 500. Both of those were guesses on my part. Increasing the number of bufer 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 performace 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 doeesn'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 contoller, 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 labelling 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 migh 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. Any damage is a straight mining/recycle sign.
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.
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. Shutdown with shutdown -h now. CD should be ejected; observe if ejection is sluggish.
15. If insertion and/or ejection is sluggish, CD(DVD) drive is a candidate for replacement. This depends on avalability. Replace if possible with a newer model. Do not replace with CR-1750 (oldest known slot loader).
16. Install Ubuntu-ppc (or Xubuntu if memory is 192MB). Machine will eject CD and reboot when done.
17. 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)
18. Update software using Synaptic Package manager.
19. 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. Probabaly choose replacement first; choose gxine if replacement is not available.
20. 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.
21. 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)