Adjusting or Tuning the Altair CPU Card

[Grant Stockly]

Even if your CPU card works, it may not have the correct timing.

You'll want to check the two clock phases 1 and 2 on pins 22 and 15.




You'll want to make sure your card follows these standards:




Someone wanted me to adjust a vintage Altair 8800 CPU card for optimal performance.

Sorry for not getting "good" pictures of the scope.

This is where it started. Phase 2 was too long according to the spec (To2). Keep in mind this card worked perfectly, but may not be stable or respond well to temperature differences.



After replacing the 4.7k R42 with a 4.3k resistor, it looks like this:

[marty]

Hi Grant;
I think I have a similiar scope to your... Only your signals look a lot cleaner than mine,,, mine look like, They were in the rough Seas !!!! Yours are basically straight and mine are not... What's up ????
THANK YOU Marty