I've written a couple of FORTH-like implementations - one way back when on a Z80 system, when I was learning Z80 assembler, running CP/M, and one on an IBM PC (

I've written a couple of FORTH-like implementations - one way back when on a Z80 system, when I was learning Z80 assembler, running CP/M, and one on an IBM PC (the original kind, with clicky keyboard) when I was learning 8086 assembler and a bit of C++, as part of an adventure-writing system. Unfortunately, the code for both has got lost (no git back then), but I can strongly recommend writing a FORTH as a way of learning a new (non-FORTH) language.