Mr. Moore,

This message is in response to the beige G3 postings at:

http://lowendmac.com/misc/03/0616.html

I can't begin to tell you how much trouble I had with getting OS X 10.2 to work on my beige G3 minitower....

I had similar symptoms to those described by your poster -- constant disk corruption, refusal to boot, etc. Disk corruption is primarily caused when a master+slave setup is used on a beige G3 that has a Rev. A ROM in it. Master+slave will seem to work w/ a Rev. A, but severe disk corruption will occur that will ruin the drive beyond anything that can be repaired by even a low-level format -- trust me, I've been a victim of this more than once. It seemed random, because some beige G3s would support master+slave, while others wouldn't. Of course, it was the ROM DIMM that was the difference.

I think just a ROM DIMM upgrade should do the trick, but I also replaced my motherboard. I think I may well have the most souped-up G3 possible (short of the 1 GHz G4 ZIF; Sonnet should give me one for "compatibility testing purposes"). I hope my experiences can help other beige G3 owners. First, I have to give a lot of credit to xlr8yourmac.com's G3 Zone which, although outdated, is a great resource: http://www.xlr8yourmac.com/g3-zone/

I had access to several G3s, many of which will never run OS X, so I was able to easily swap the Revision 1 motherboard with a Rev 2 mobo.

How to tell which ROM you have:

• If the video chip on the motherboard says "ATI RageII+...," it's Rev. 1 (no slaves, Rev. A ROM DIMM)
• If the chip says "ATI Rage Pro...," it's Rev. 2 (Master + Slave OK, Rev. B ROM DIMM)
• If the video chip says "ATI Rage Pro Turbo...," it's a Rev. 3 - no difference from Rev. 2, except the ATI Rage Pro Turbo has AGP compatibility, which is unnecessary since the Beige G3 has no AGP slot (Master + Slave OK, Rev. B or later ROM DIMM).

[Note: Beige G3s with Rev. A ROM DIMMs should be avoided, due to disk corruption issues mentioned in this article. If you only plan to have one hard drive in your computer, then you may use a Rev. A machine at your own risk.]

The only disadvantage I can think of that might make you want to upgrade the motherboard [versus just upgrading the ROM DIMM] from a Rev. 1 to a Rev. 2 or later is that the Rev. 2 and later can supposedly play DVDs in OS 9. However, you'll need at least a Radeon 7000 Mac Edition PCI card [Note: Radeon 7000 now unavailable; get a Radeon 9200 instead] to play DVDs in OS X, regardless, so it's not that important unless you're an "OS 9 only" person.

Other World Computing used to sell ROM DIMMs for precisely this purpose, but they've been out of stock for awhile. The only source I know of that still has ROM DIMMs in stock is We Fix Macs at 1-800-We-Fix-Macs (Palo Alto). They also sell VRAM and nearly any other part for a beige G3. You may have to ask for Art, the owner, because this is an obscure part. There are three ROM versions: Rev. A, B and C. I tried all. The rev. A *definitely* won't support more than one ATA drive per cable (i.e., only a master drive on each IDE bus). The rev. C is fairly obscure and was shipped by Apple as a replacement ROM at the end of the Beige G3's life. It may have also been included with the 300 MHz models -- I'm not sure. It should support up to four onboard drives, but as I recall, it didn't seem to like my Tempo Trio card (which was noticeably faster with my ATA/100 drives than the onboard ATA/33? ATA/66?).

Refer to this article for more on ROM DIMMs: http://www.xlr8yourmac.com/g3-zone/IDE/

The machine now works well with a Rev. B ROM and the latest flash ROM update from Sonnet on my Tempo Trio. For your curiosity, here is the configuration:

• OS X Server 10.2.7 [Update: now OS X 10.3.8 - you'll need XPostFacto to install newer versions of OS X on any Mac that didn't come with USB from the factory]
• Beige G3/500 MT (originally 233 MHz) [Update: now a G4/550 ZIF CPU]
• Connected to Motherboard
  • 768 MB of PC100 RAM (3 x 256MB PC100 chips. Would not advise PC66 because it limits overclocking of 66 MHz bus speed)
  • AV personality card (only audio works in OS X)
  • Additional onboard VRAM (6 MB total) w/ Apple 21" monitor [Update: On-board video was no longer needed, so the 4 MB VRAM chip was pulled from the motherboard and put into a tray-loading iMac]
  • 18 GB UltraSCSI HD connected via 50 pin adapter (boot drive b/c does not have 8 GB size limitation like ATA drives) [Update: SCSI drive pulled when I went from Mac OS X Server 10.2.x to Mac OS X 10.3.x - using only ATA hard drives now. As I recall, Mac OS 10.3.x is less friendly to SCSI drives than 10.2.x]
  • Internal LaCie 12x SCSI CD-RW (iTunes/Disc Burner supported)
  • Internal Apple ATA 4x DVD-ROM (pulled from a G4 Mac - plays DVDs only if monitor connected to Radeon is primary display)
  • OEM Zip 100 drive w/ bezel
• PCI:
  • Apple 10/100 ethernet card (BTO option pulled from another beige G3) [Note: Mac OS X also supports many inexpensive, third-party PCI Ethernet cards that did not work in OS 9]
  • Radeon 7000 Mac Edition (32 MB) w/ 21" Dell Trinitron monitor [Note: Radeon 7000 now unavailable; get a Radeon 9200 instead]
  • Sonnet TempoTrio (FW/USB2/ATA/133)
    • Western Digital 120 GB/ATA/100 HD (WD1200JB 8 MB cache) [Update: drive worked great, but it was put into another computer]
    • Maxtor 80 GB ATA/100 HD*
    • Epson Perfection 1200u SCSI scanner (ViewScan driver)
    • Apple Pro USB keyboard, Logitech mouseman marble optical
• Other
  • 350 Watt PC power supply unit (all Beige G3s work with standard PC ATX power supply units if the jumper on the motherboard is set to "PS2 Supply" instead of "Mac Supply"). [Update: the "upgrade" power supply failed, so I put the original 240W one back in and all is working fine]

*Partitioned for boot volume in first 8 GB for OS X compatibility. [Note: I used NetInfo Manager to point the Home Directory to the second, larger partition, while OS X has to reside on a partition < 8 GB]

I hope this info can benefit your readers. Great Site!

Regards,
Kevin Pedersen
Marintellect Design and Consulting
http://marintellect.com/