Just finishing off an Apple-1 replica and thought I'd test it by playing a game of Lunar Lander. Chose the version written in BASIC to give the full memory a test....Hmm, something not quite right....And who is this Corgy Cojen chap?? :bigsmile:
Are you using the correct character generator? What component are you using?
Turned out to be a flaky shift register. The fault only showed up after it had been on for a while.
And who is this Corgy Cojen chap?? :bigsmile: ]
Yep that would be me and I would think a shift register was the problem as they are the most likely problematic component to mess with the display in that way.
I'm curious, what are you using a shift register for?
I haven't looked over your schematics but I was under the impression that your design was similar somewhat to the Briel version.
I guess I need to study your schematics more.