"But what about availability? True Commodore was a great company but they
are effectively dead now. No promises on just how likely we will be to find
any of these."
If I had the time, I'd find a microcontroller that was close enough
to the 65xx bus timing and do the whole thing in a single part. You
could probably do a whole CAT box in a 68HC11 and you wouldn't have
the problem of trying to find out of production parts like 6551's or
6532's at all. All I was saying was that there was a three chip
solution to adding a serial port to the existing design..
