Comment by tdeck
2 days ago
If you're interested in learning more about how FORTH works I, I can recommend two very old books.
Starting FORTH https://archive.org/details/LeoBrodieStartingFORTHIntroducti...
Threaded Interpretive Languages https://archive.org/details/R.G.LoeligerThreadedInterpretive...
The latter doesn't even mention FORTH, and describes some very archaic CPU architectures, but I found it fascinating because it builds things from the ground up.
Loeliger's 'Threaded Interpretive Languages' jumpstarted my career in the late 1970s: I built a networked water management system based on their code, which was my first big project, earning me £1,500. Note that there's a bug in their code (I no longer remember exactly where) so getting it off the ground was tricky.
In particular learning about threaded interpreters, sub-routine interpreters, etc is very eye opening. That and really internalizing that everything, even code, is really just numbers.