Power Mac G4 + PC Radeon 9000

I’ve acquired yet another retro machine – this one a Power Mac G4 MDD. There are a few reasons I find it appealing:

It’s one of the last machines that natively supported Mac OS 9
It has the benefits of a modular tower, which makes repairs much easier (I’m looking at you iMac G4)
It’s cool

Surprisingly it started on the first boot attempt! The PRAM battery was dead, which was expected, but other than that it seemed perfect… for a while. The next day when I tried to boot it I saw only a black screen, so the troubleshooting started.

Troubleshooting

To keep things brief it all came down to two components in my case (literally) – either the power supply or the video card, which is an ATI Radeon 9000 Pro Mac Edition 64MB.

Dead Radeon 9000 Pro Mac Edition with ADC connector

After trying some spare PC AGP cards I was able to boot consistently with a PNY GeForce 2, telling me the power supply is probably OK. I could’ve stopped here but the graphics performance was terrible with the GeForce 2 and I never got hardware acceleration to work.

I attempted to flash a new ROM to the card but kept getting rejected, so I decided to go in another direction.

Replacement research

There are a few sites that were extremely helpful in this quest to determine what cards could be used in the Power Mac:

If going with a PC version of a video card some will need to be re-flashed with Mac firmware and some also need pins disabled.

I decided to go with another Radeon 9000 but not a Mac Edition – one for PCs only. This would mean higher availability in the used hardware market, a lower cost, and no work to disable pins. It also meant double the VRAM – 128 MB instead of 64.

I wouldn’t be utilizing the extra ADC power port in the AGP slot nor would the card supply an ADC connector, but for me that’s OK.

Initial state

When I ordered the card from eBay the description mentioned a failed fan so I needed to address that first.

The board’s connector outputs 5V DC and most of my other cards do 12V, but I found a spare fan I’d used for a Raspberry Pi that would work. It’s a bit of a rig at the moment, but a wire tie holds the fan tightly to the original heat sink.

Once I was sure the new fan setup was working I popped the card into the Mac just to see what would happen. Turns out, nothing. Just a black screen. I don’t think Mac OS 9 even booted.

Fixed in a flash

I pulled the card out of the Mac and inserted it into one of my trusty Gateway Slot-1 machines with an AGP port to flash it with the Mac firmware.

Gateway tower with the Radeon 9000 inserted

The PC needed two files:

The ATI flashing utility (version 3.25 in my case worked)
The Radeon 9000 Mac ROM

After transferring the files I booted into DOS and followed this sequence in the directory where I’d stored the files:

atiflash -i to make sure the adapter was detected and learn the adapter ID (0 in my case).
atiflash -s 0 backup.rom to make a backup of the PC ROM.
atiflash -f -p 0 [mac_rom_filename.rom] to force-write the Mac ROM firmware.

Writing the Mac firmware to the video card

I then removed the card from the PC.

Flip the switch

The last step to prepare the card for the Mac was to remove the protective tape at the top left and flip switch 2 (the top one pictured) from MF to SF.

Success!

With the card reinserted into the Power Mac we boot right up! Until the ATI drivers are installed there will be no hardware acceleration. The ones I’m currently using are the drivers supplied with Mac OS 9 Lives 9.2.2 and they are working great. 🚀