Early Hacks

Here we see a hack I did more than fifteen years ago, when I lacked much of the knowledge, experience, and materials I have at my disposal now. I overclocked my PowerMac G4 Sawtooth. Stock it ran at 450MHz; I was able to get it to run stable at 500MHz.

The CPU card for these old G4s used a few resistors to set the bus multiplier. For this old Sawtooth model, it was R7, R9, R11, R13.

I removed the resistors that were there originally and soldered some enameled magnet wire in their place. On the other end, I soldered a set of DIP switches to allow me to experiment with the multiplier without a lot of effort. I only had this bank of six switches, so two are unused. And then, lacking anything better, I wrapped it in tons of electrical tape.

I tried setting the multiplier up to 5.5x to get it up to 550MHz, but it wasn’t stable enough to boot. At 600MHz it wouldn’t even power on. I believe it could be set down to 3.5 or 3.0, should I ever have any reason to underclock the machine.

I used this computer, overclocked to 500MHz and running MacOS 10.5 for years before passing it on to a family member who used it for several more years. Never once had an issue with the overclock or my crude hack.

In the 15 years since, the tape has obviously collected a lot of dust, but the computer still runs fine. I’m just a extra cautious when it comes to working around those fine wires.