I've built an RC6502 SBC Apple 1 replica, and I'm having an issue right off the bat. I asked about this on the RC6502 group on Facebook, and we weren't able to come up with a solution. So I thought I'd ask the Apple 1 gurus here.
After some initial serial issues, I have it up and running at what seems like a working monitor prompt. But when I try to run the machine code test program in the Operations Manual, I get no output. I can type in a Hello World loop BASIC program and it works fine, but I can't get machine code to run from the monitor. Any ideas? I'd like to get this working, then see if I can make an ACI board that will work with it.