COMMODORE PET 8032
I picked this machine up on Ebay which included a 8050 Dual Disk Drive. Like the 4032 I purchased earlier this 8032 and the Disk Drive were sold as none working.
The 8032 would prove to be much more difficult to repair than the 4032, there were several components that turned out to be faulty. The full thread detailing what I did to get it working can be found here.
To sum up the problems I had with the 8032:
- 3 Broken ROMS (Kernal, Display, Basic 1)
- 4 Broken 2114 display RAMS
- 1 broken 4116 main RAM
- 2 broken 6520's
- 1 broken 74LS244
From my own experiences fixing my 8032 and 4032, here's a list of common problems that may stop a PET from working.
Display RAM (Static)
The usual symptoms are random characters on the screen when booting. This will not stop the machine from responding to keyboard input (assuming the keyboard contacts are good), so to verify if the rest of the machine is functional just press a few keys and you should see the characters changing on the screen in response to the key presses.
Main RAM (Dynamic 4116)
When powered on the PET will display the amount of good RAM available. The PET needs only the 1st 1KB of RAM to be good for it to be able to boot into BASIC. The RAM the 4032 uses (4116) are fairly common dynamic RAM and can be picked up cheaply on Ebay or if you have a spare ZX Spectrum lying around (like I did) as this uses the same chips fro its lower 16K of memory.
If any of the ROM's are faulty they can be swapped out for 2532 EPROM's which again, like the RAM, are fairly easy to get hold of on Ebay.
- All Commodore PET ROM images can be found here.
A very useful tool for diagnosing PET problems PETVet board that not only gives you 32K RAM, it also allows you to diagnose most problems with any PET.
- Infomation about the PETvet can be found here.