PowerMac IV: The Voyage Home


I've decided to finally get a real computer that would give me room to stretch out with. As a sufferer of a diseased relationship with technology, there was really only one choice: A sixteen-year-old, broken PowerMac G4.

A quick look on Marktplaats finds a lot of old Macs, most of them in Amsterdam or strange places that take three hours of train hopping to reach. Dutch people, it seems, are averse to putting anything bigger than a Christmas card through the post.

Then I see it

Quicksilver G4, Dual 1Ghz, and only 3KM from my house. The seller was a hardass and wouldn't take 40. A quick inspection in his driveway showed it had a Radion 9000 Pro and a SATA card thrown in, so for 50EUR I figured it was a fair deal.

I made the journey in no time at all. I don't drive so some straps helped the G4 ride a bike. The whole way with one hand holding it behind my back, and it got more stable the faster I went.

I was annoyed to learn the power supply was on its way out, which seems to happen a lot to these models. In my case the capacitors were starting to puke.

I decided the best thing to do was to swap the PSU for a normal PC one. I'd lose the pins that power Apple's proprietary cinema displays, but that doesn't matter because they are terrible.

The beginning is easy enough. Apple's towers of the time were famously Open Minded. This let me scoop out its guts with no effort.

Look at all those gubbins. The power supply is held in by a bracket that's bolted behind the drive bay. I also pulled out the exhaust fan to give it a clean.

Once I'd gotten her emptied out I went a step further and took off the plastics so I could clean out the dust. Unlike my iMac, the Power Macs are ordinary steel cases wearing a disguise.

The pinout is different between Quicksilver and ATX power, so I chopped off the wires for the motherboard and tidied up the length.

In comes the organ donor. I'm lucky that Dutch people love junk shops - this Pentium IV turd came fully working for ten euros.

New power supply gets a haircut, and the old loom matched to fit.

Now we have to face an electrical problem. The Mac expects it's power supply to offer 24V, and this is used for three things. The first is "trickle power", which lets it respond to the power button when it's turned off. The second and third things are powering Apple's ADC monitors from the computer, and firewire. No ATX power supply makes 24V.

Luckily the motherboard will be happy to run with a 5V trickle supply. Using diodes, we can have the 24V input rise to 12V once the computer starts, which is enough to get Firewire working. I don't need ADC monitor power, but it could also be achieved using separate 24V supplies sold on ebay.

Reassembly is the reverse of disassembly.

With the donation of a 1TB hard drive she boots right up, ready for a fresh install of Mac OS 9.2