[blkhp19]

It's also a fun one to write an emulator for. There are plenty of example programs out there to test, and they draw graphics by writing bytes to a frame buffer at some offset in memory. You can read from that region in memory, interpret each byte as a color from a preset palette, and use it to display visual output / graphics.

I wrote one in Swift a few years back, and then ended up developing it further into an NES emulator capable of playing Donkey Kong. It was a great learning experience.

[stevekemp]

I recently found a 6502 emulator written in Z80 assembly, which runs under CP/M:

https://github.com/davidly/a1/

The full title is " 6502 and Apple 1 emulator for 8080/Z80 CP/M 2.2 machines " which I guess gives a better idea of the (impressive) scope.