Commodore Colt (PC-III): cleaning, repairs, and testing

[retro-pc_user]

Welcome to another retro PC restoration and testing thread.

On this episode of retro PC repairs: the one and only Commodore Colt PC.

Specs of the system:
Siemens 8088 10MHz
8087 FPU
unknown amount of RAM
360KB DD FDD
20MB Seagate XTA hard drive

The battery had leaked, unfortunately, however, it's not the worst I've seen and the corrosion cleaned off nicely (still needs a bit more done, but it's better than nothing).

Pictures of the system itself:

















Gallery:

https://imgur.com/a/LewZkrz

Motherboard:









Gallery:

https://imgur.com/a/aSHjbkY

More to come. Stay tuned.

Archived the BIOS chips and I'll archive the diskette as well to play it safe.

 

[jafir]

There would have been a gw-basic disk and also some wordstar disks too. I think they are archived at winworldpc. You should check and see if yours is a different version that might also need archived.

I’ve got a set of them, but mine are the same that are already out there.

 

[whaka]

really love the case.
this mix looks like if an A1000 did dirty things with an A3000, and give birth to this :D

 

[Benedikt]

One interesting aspect of this machine is that the on-board video chip supports 320x200 pixels in 16 colors in a Plantronics ColorPlus compatible mode. Software support leaves a lot to be desired, but you can use cshow and my SCI driver for Sierra adventures.

 

[retro-pc_user]

Well, the system broke down mid-stream yesterday and I looked everywhere for bad traces or chips and the only thing that gives a sign of life is the POST card showing FF7E (FF from the past OK POST before it crapped out and 7E is the current code). The display turns on, yet nothing shows on the screen and the keyboard has all 3 lights illuminated.

I checked the ROMs for missing data and they're all good, the CPU and FPU do get power (they get warm to the touch), and the video chip does have power as well. I asked on Reddit for guidance and the one recommendation was to check the MOS 5720 chip and the logic ICs for the TTL and data bus for any broken pieces (well, the TTL and data bus chips will be read using my TL886II+ tool to look for any issues).