I've spent the day diagnosing my homebrew Apple 1 replica, based around Vince Briel's Replica 1 Plus. The Woz Monitor is loading and I can get into BASIC using E000R on the larger ROM, so that's a great sign. I'm using a real CRT screen but input is via serial to PuTTY on my Windows 10 machine.
The only real trouble I'm having with it still is with repeating characters. Whenever I type a 'space' it produces a single space character. But whatever character I type next, it first produces another space character, before sending the requested character. So I'm basically getting double spaces between every word and command. It's not just the space character, either.
I get doubles every time with the space character, about 80% of the time with the 0 (zero) character, and about 10% of the time with other characters. It even happens with Return, for example, if I type F000, and then Return, I will sometimes get an extra 0 before the Return character it sent, which sends F0000 and produces an error. I'm suspecting the Propeller has an issue, I've checked my work carefully several times and it seems like an oddly specific error.
I haven't actually wired up a PS/2 keyboard yet, I need to do that next to see if I get the same repeats, just to narrow things down further.
Have any Apple 1 replica owners/builders had an issue like this?