[Coco] 6821 PIA Chip Bad?

[Eric Keppel]

Hey folks,

I just wanted to update this thread to say that replacing the PIA with a
new one fixed the problem in that old nearly beat-to-death-by-USPS 16K
Coco-1!

Unfortunately, a similar problem has just cropped up in my Coco-2 that I
upgraded to 64k a month or so ago.

At least one symptom matches in that the same group of keys on the
keyboard go out after the machine has been on a few minutes - 'n' 'v'
'.' 'f' '6', and possibly one or two more.  My 26-3136 Coco-2 doesn't
have socketed PIAs like the 26-3002 Coco-1 does, so I will have to
de-solder to fix this one.

It's a shame that both of these machines have had problems - they both
had intact warranty seals when I got them.  :(

On the bright side, I have a 128K Coco-3 on the way (thanks, eBay) so I
will have one of each soon.

Cheers,
Eric