Testing Cinematronics CPU's

I've been trying to think of some methods for troubleshooting
Cinematronics CPU cards that would be fairly easy to follow - so that
non-electrical engineer type people like myself could fix them without
feeling frustrated. - then document the procedures. I've already got the
basic ones down - (check reset pins, check data lines, crystals, verify
roms are good, etc.)

One idea I have in mind is to create a ROM that has a bunch of "do
nothing" instructions, or I guess what you would call nops? The last
instruction on the ROM would be to jump back to its first "do nothing"
instruction and keep repeating. Put this rom into a working board and
then document each pin on each chip for reference - which someone could
use along with a logic probe on a non-working board. - I'd document the
troubleshooting into separate program functions to make it easier for the
reader to follow what's going on.

Just some ideas - Anyone have comments on this?

I've got about 5 non-working boards - so I'm sure that by the time I'm
done fixing all of them I'll have some sort of helpful procedure written
out.

Matt

PS. Mark J. - I'm still finishing my G08 contributions. It's hard to get
anything done over the holidays.
Received on Thu Dec 31 00:23:25 1998