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▲ addaon 2 days ago

> how does a Forth interpreter work in a Harvard architecture microprocessor

You compile to "direct threaded code" in data memory; direct threaded code represents a sequence of calls as a sequence of addresses to call. So while "normal" threaded code (what Wikipedia calls "subroutine threading") would just have

    call word_a
    call word_b
    call word_c
And then executing that means jumping to the first instruction, direct threaded code would have

    &word_a
    &word_b
    &word_c
And then there's a suuuuper tiny runtime (like four of five instructions, literally) that has a "runtime instruction pointer" or whatever you want to call it, and just increments that and does an indirect call through to the next word whenever it's returned to.