Just seen this little video of PCB design:
https://www.youtube.com/watch?v=qdfqX5TfKP8It was a parallel printer buffer intended for the BBC Micro (6502 based home computer in the UK, c1981).
The device uses the R6511 "microcontroller" variant of the 6502. He developed all the software for it on the BBC Micro - famous for having a built in 2-pass assembler as part of its BASIC ROM.
-Gordon
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Gordon Henderson.
See my
Ruby 6502 and 65816 SBC projects here:
https://projects.drogon.net/ruby/