SWTPc 6800

From: Louis Schulman <louiss_at_gate.net>
Date: Wed May 22 22:17:23 2002

It works!

After a few consultations, I have my vintage 1975 SWTPc 6800 up and
running!

Well, I learned several things. First, if you are looking for a short,
you have to have a very clean board. If there is lots of flux and
junk, you can't see anything. So, I really scrubbed my MP-A (processor
board) clean,
which let me find a couple of tiny solder bridges.

Second, suspect crazy connectors. This board has a weird "ZIF" socket
for the processor, where it is easy for the pins not to make contact if
they are not bent right.

Third, it is always the weirdest extinct bus transceivers that go
bad, since they are the most difficult chips to find.

And finally, a cheap Radio Shack logic probe can "see" a lot of what
you
can see on an oscilloscope, if you listen to the tones carefully. The
data train on reset makes a nice little set of beeps. When I heard it,
I got goose bumps.

Now, on to try and get some software running!

Louis
Received on Wed May 22 2002 - 22:17:23 BST