ti84-forth VS pijFORTHos

Forth also requires very minimal resources to implement which can be fun in constrained environments. Here it is on a TI-84+ calculator[0] or even a computer in The Powder Toy.[1]

The runtime design is a little quirky but straightforward and you can extend the system as you execute (or even change interpreter semantics), or add optimizations such as some form of JIT quite easily.

[0] https://github.com/siraben/ti84-forth

[1] https://github.com/siraben/r216-forth

Some time ago I wrote an implementation of Forth that runs on the TI-84+ and TI-83+ calculators directly inspired by Jonesforth.[0] It runs under TI-OS as well, but the amount of available space is somewhat limited. On another implementation I wrote[1] you have full access to the calculator hardware and memory from Forth.

[0] https://github.com/siraben/ti84-forth

[1] https://github.com/siraben/zkeme80

On the TI-84+, assembly programs still work and it's still a test-approved device. I wrote a Forth interpreter[0] that can interop with the syscalls as well

[0] https://github.com/siraben/ti84-forth

And having run across jonesForth (https://github.com/organix/pijFORTHos/tree/master/annexia read the .s file and then the .f file) and basically the idea of building your own personal software stack from scratch, but part of the problem is just having hardware that wasn’t designed to be super complicated to interface with (like USB being much more complicated than PS/2 or wiring up your own grid of switches for a keyboard).

I want to write one for bare metal (non-Linux) raspberry pi (ARMv6 32 bit on Raspberry Pi 1 and Zero; ARMv7 and ARMv8 on higher models and also supports 64 bit). I want to have no dependencies required though so was thinking of bootstrapping it with nothing but machine code (determined initially with the help of an assembler and documentation of course). Someone has already ported jonesforth the Raspberry Pi[1] but using serial i/o as the user interface and it has dependecies to build it, but I should be able to get ideas from how they coded their assembly parts compared to the original jonesforth. I want to be able to use HDMI for the screen (already tried it out with some bare metal tutorials in assembly so that's do-able) and again, with no dependencies. And I want to show people how to do it themselves, not just have it be something to run that they don't understand fully. It should also be possible to have the forth kernel build/assemble itself if needed, or cross-target another platform.

I know I'm all talk right now, like you say, I need to manage my free time so that I would have the "copious free time" to work on this.

[1] https://github.com/organix/pijFORTHos