This is repository houses an OCaml emulator of Ben Eater's 6502-based breadboard computer:
For the CPU we use Vigile Robles' excellent 6502-ml. The only program currently supported in the CPU is (Ben Eater's version of) Steve Wozniak's Wozmon program for the Apple I, which was adapted to run for the breadboard computer.
A challenge to emulate Wozmon is to support keyboard I/O to run concurrently as the CPU is running. We use the concurrency library Lwt for this purpose. This allows us to define promises corresponding to user input and CPU cycles and combine them.
After installing the dependencies with
opam install .
Try running
dune exec wozmon
to start the Wozmon REPL. Within the REPL, type:
0:A9 0 AA 20 EF FF E8 8A 4C 2 0
And then type R to run the program. This should display a continuous stream of ASCII characters.
I had been following along Ben Eater's incredible series of videos on the 6502 computer for the better part of two years. I had been wanting to build an OCaml emulator of the breadboard computer as I was too scared to keep digging out the breadboard everytime a new video came out, lest I misplace a connection or two and tarnish that work of art. As such, this would not have been possible without Virgile Robles and Ben Eater's work.
- Support MS BASIC.
- Support more hardware.
- Use Eio?