[Coco] CoCo 2

[Rob Rosenbrock]

After watching all of those videos on Youtube, I just couldn’t resist the urge to bring my old CoCo down from the attic… I wanted to see if it still worked, or if it needed repair.

I couldn’t find my old CoCo 2. Not sure what I had anymore, but I do know that I was repacking one of them so the circuit board must be around someplace. I can’t imagine that I would have torn my only CoCo 2 apart.

I found a 64K Extended CoCo in kit form - still in box. I don’t need to test it to know that it doesn’t work… Would have to build it first. LOL I don’t know if this has value or not, but I’ve waited so long to build it that I don’t want to even take it out of the box.

I settled for bringing down my CoCo 3, which was upgraded to 512K using Radio Shack’s 26-3334 Expansion kit. (Also found the box for the upgrade with my original 128K chips!) I still need to bring down my CM-8 and disk drives.

The CoCo 3 powers up, but the characters are all fuzzy. According to my oscilloscope, the 5v line is rather noisy. There’s some rather dark goo around the base of a couple transistors in the power supply section. That would either be some glue or those caps have leaked. (or both) All of the keys seem to be working fine. And there’s no sign of yellowing on the keyboard or case.

I would still like to play around again on an old CoCo 2 with 64K. Going rate on eBay seems to be around $100 for a 16K. Typically a 26-3134A. I’m looking for ideas around a 64K upgrade.

Any recommendations?