[Coco] So, my CoCo 3 may be having some trouble

[Christopher Smith]

I just noticed that one cart I've tried -- the old "music" cartridge -- will work on my CoCo 1 just fine, but the CoCo 3 shows garbled graphics and occasionally screeches at me when I try to boot it.  I don't think that this cart should cause any trouble with the newer machine, so I wonder if there's something with the machine itself.  One thing I can say about it is that when I got it, the machine wouldn't even show the BASIC prompt before I reseated the GIME chip.  That done, it seems to be mostly working, but with an occasional bit of flakiness.  I can't even tell if it's flaky because I've got some software it just doesn't like by design, or it's flaky because it has actual problems.  Once it gets going with something, it tends to work just fine.  It's mostly during the process of loading and executing a program that something strange happens.

Now, my current question is, do I perhaps need to clean the contacts on the GIME?  I've heard advice about using a pencil eraser to rub the surface deposits off of the chip contacts.  Is that a good idea, might it help?  I do have the old GIME chip in here.  I don't _think_ that should be causing this problem, but is there any chance I'm wrong?  Should I look for a replacement chip?  Is there anything else that I should check?  As I said, it usually seems ok.  It's an intermittent thing with respect to system use; maybe consistent with certain software.

If I'm lucky I'll have a disk drive very shortly, so I'll be able to try NitrOS-9 and see what happens.

Chris


-- 
Christopher Smith
Systems Engineer, Wolfram Research