kalleboo's retro tech blog

PowerMac 8500

Buying it

The PowerMac 8500 was the first addition to my retro mac stable. I was browsing HARD OFF one Friday, and among the usual piles of old NEC PCs, I spotted... a beige Mac! First time seeing such a treasure here! I had to have it... It would't fit in my bike basket so went to pick up a carsharing car and brought it home.

Yes yes I paid too much for it...

The state of it, cleaning & retrobrite

It was quite yellowed (partially due to tobacco), and the plastics were very brittle. Just opening it the first time it snapped off the plastic motherboard guard, taking a surface-mount capacitor off with it that I had to resolder.

The PRAM battery was stone-dead, so I ordered a replacement of that online. No leakage though!

I did some research online, and none of the usual suspects containing the essential chemicals for retrobriting were available in Japan, but instead I found out that a common detergent additive had it. The concentration was low, but my supermarket had a generic version that was dirt-cheap.

So my first step was taking all the visible parts off, cleaning them thorougly with alcohol (ewww all that tobacco), and then left them in a retrobrite bath on the balconey for a couple of hours.

There was a massive difference, but the plastics still aren't as white as the metal parts of the machine, so I want to give it a second go at some point.

Getting an OS on there, SCSI2SD, and the current state of death

It didn't come with a harddisk, OS CD or boot floppy, so I had to get some kind of boot medium. I found an original System 7.5.3 boot CD for this model on Yahoo! Auctions and it was soon in my possesion. It boots!

The next step is, what do I install onto? SCSI harddisks cost a fortune and will probably die soon anyway. Luckily, there is a solution, the SCSI2SD. You pop an SD card in it, and it turns it into a SCSI drive. A lifesaver for old Macs.

Unfortunately, I never got it working well with the 8500. To begin with, it just wouldn't format. I tried a ton of different utilities and SCSI2SD configurations.

I was in contact with the developer, and he got me a custom firmware. This custom firmware got me further - I could now format the drive and run System 7.5.3! But installing OS 9, it would freeze on boot (solid SCSI activity light).

I was going to debug it more when I slipped and shorted some pins on the bottom of it to the case of the 8500, killing both the SCSI2SD and the Mac!

Next step

Obviously I need to fix the Mac. Hopefully it's something very basic like a fuse in the PSU...

Last updated: 2019-03-21
Back to kalleboo's retro tech blog index