CP/M-65: CP/M on the 6502

This is a native port of Digital Research’s seminal 1977 operating system CP/M to the 6502.


Unlike the original, it supports relocatable binaries, so allowing unmodified binaries to run on any system: this is necessary as 6502 systems tend to be much less standardised than 8080 and Z80 systems. (The systems above all load programs at different base addresses.)

Currently you can cross-assemble programs from a PC, as well as a working C toolchain with llvm-mos. For native development, there’s a basic assembler, a couple of editors, and a BASIC. You need about 20kB to run the assembler at all, and of course more memory the bigger the program.

The usefulness of this project is debatable, but that doesn’t make it any less cool.