swapforth VS durexforth

Thanks! Found the port of this to the board I want :) https://github.com/jamesbowman/swapforth/tree/master/j1a

It's a standard thing to do in EE curricula; you normally do it in a one-semester class, and there are literally thousands of open-source synthesizable CPU cores on GitHub now.

To take two examples to show that designing a CPU is less work than writing a novel:

- Chuck Thacker's "A Tiny Computer", fairly similar to the Nova, is a page and a half of synthesizable Verilog; it runs at 66 MHz in 200 LUTs of a Virtex-5: https://www.cl.cam.ac.uk/~swm11/examples/bluespec/Tiny3/Thac...

- James Bowman's J1A is more like Chuck Moore's MuP21 and is about three pages of synthesizable Verilog: https://github.com/jamesbowman/swapforth/blob/master/j1a/ver... and https://github.com/jamesbowman/swapforth/blob/master/j1a/ver.... You can build it with Claire Wolf's iCEStorm (yosys, etc.) and run it on any but Lattice's tiniest FPGAs; it takes up 1162 4-input LUTs.

I haven't quite done it myself. Last time I played https://nandgame.com/ it took me a couple of hours to play through the hardware design levels. But that's not really "design" in the sense of defining the instruction set (which is also kind of Nova-like), thinking through state machine design, and trying different pipeline depths; you're mostly just doing the kind of logic minimization exercises you'd normally delegate to yosys.

In https://github.com/kragen/calculusvaporis I designed a CPU instruction set, wrote a simulator for it, wrote and tested some simple programs, designed a CPU at the RTL level, and sketched out gate-level logic designs to get an estimate of how big it would be. But I haven't simulated the RTL to verify it, written it down in an HDL, or breadboarded the circuit, so I'm reluctant to say that this qualifies as "designing a single CPU" either.

Also worth checking is the Swapforth Github repository.

An actively developed version of Forth for the Commodore 64, based on the Forth 2012 core standard.

Just the durexForth manual from github. It's possible I missed something searching through it, but the example programs they have in the repo do have examples of word definitions starting on the first line of the file. Additionally, simply adding a comment to my own code didn't make a difference.

For the interested, there is a modern open source C64 Forth called DurexForth.

I know you said you wrote this in Kick Assembler, but I really feel like I should plug 64tass a fantastic cross-assembler. I've used it for my own reverse engineering projects. You might also want to look into DurexForth not because I think you should write this in Forth instead of ASM, but because it might help you to think about how to write things like a quest interpreter.

If you’re into this you may also like durex forth: https://github.com/jkotlinski/durexforth

A modern C64 variant, as well as CollapseOS which is a Forth based 8-bit OS: https://collapseos.org/