Some of the things I learned from implementing a FORTH on a CP/M box back in the early 1980s were - writing Z80 assembler - using the assembler and linker -

Some of the things I learned from implementing a FORTH on a CP/M box back in the early 1980s were - writing Z80 assembler - using the assembler and linker - getting a clue about how the CP/M file system worked (it didn't, very well) - writing a number of utilities (VT52 emulator, PacMan clone & stuff) in FORTH, which was fun - macro programming at compile/runtime using things like BUILDS/DOES It's a lot of fun and you don't need to invest much time in it to get things done.