Altair Repair

From: Marvin Johnston <marvin_at_rain.org>
Date: Mon Aug 2 10:07:37 2004

I fired up an Altair and found it didn't behave as it should (tested
with MITs and Polymorphic CPU cards.) Doing an "Examine" does not load
the switch settings into the program counter. Doing an "Examine Next"
seems to increment the program counter by 3. The preceeding was done
with and without a memory card. I tried the "Deposit" but had no way to
see what I was doing since the switch settings apparently weren't being
loaded. Finally, the "Deposit Next" increments the LEDs. One other
strangeness, when I connect the Data Display cable to the MITS card, the
"Stop" switch ceases to function although the "Start" seems to work
fine.

I do have the schematics and will start to dig into it later this
morning. BUT, I was hoping to short circuit some of the troubleshooting
time if someone on the list has experienced something like this :).
Thanks!
Received on Mon Aug 02 2004 - 10:07:37 BST