zeptoforth VS jonesforth

microcontroller options are interesting, also Forths (https://github.com/tabemann/zeptoforth)

Patch-level release 1.0.1 is out. This release improves the disassembler, particularly adding the ability to properly disassemble string literals.

This is a definite shameless plug, but I would recommend my zeptoforth - it has strong support for the RP2040 (e.g. the RPi Pico), including peripheral support and support for executing on both cores, and also has support for a number of STM32 platforms, and comes with a range of example code, documentation, and a wiki.

The release itself is at https://github.com/tabemann/zeptoforth/releases/tag/v0.45.0

Zeptoforth has this, but it’s for embedded systems. https://github.com/tabemann/zeptoforth

I initially implemented a rather Forth 2012-like wordlist system based on GET-ORDER, SET-ORDER, GET-CURRENT, SET-CURRENT, and WORDLIST for my Cortex-M Forth, zeptoforth. However, I ended up finding these quite cumbersome and error-prone to use in code that makes heavy use of wordlists to control the namespace, as is the case with zeptoforth. As a result I decided to completely remodel wordlists into a module system which, while internally based on those five words, is outwardly much more like the module systems found in other languages.

Multicore support for the RP2040 with zeptoforth has been in the works for a while but up until the last few days has not been mature enough for me to even consider including it in the devel branch of zeptoforth. However, now it has reached the point where I can run multiple tasks simultaneously on separate cores. I have a working test that blinks the LED on the Raspberry Pi Pico at two different rates in two different tasks, one on each core, while simultaneously writing an asterisk to the console once every second from the second core and having a usable REPL in the main task on the first core. It should be noted that even the Micropython does not do this, as it only allows two tasks, one per core, rather than allowing multiple tasks to run on each core separately.

I am the developer of zeptoforth, which is the main Forth I am using at the present. It supports the RP2040 (particularly the Raspberry Pi Pico, but it should work on other RP2040 boards), which I have been working with lately, and the STM32F407, STM32L476, and STM32F746 DISCOVERY boards. Note that it is not a desktop Forth; for that I would probably just recommend gforth.

zeptoforth 0.21.0 (https://github.com/tabemann/zeptoforth/releases/tag/v0.21.0) is now out, and introduces support for the RP2040 microcontroller (e.g. Raspberry Pi Pico, any RP2040 board with Winbond Quad SPI flash should work). Note that it comes in UF2 format, so one codes not need to solder pins for SWD onto one's Raspberry Pi Pico format to load it, and also the Makefile automatically generates UF2 files. Furthermore, when said UF2 file is first loaded, it erases flash above it up to the 1 MB mark, so one does not need to use OpenOCD (with SWD) or a special eraser UF2 file to clear old code out of flash.

The result of this is zeptoforth, which I have been developing for about a year and four months. One could say that it fits the same niche as Mecrisp-Stellaris, and it admittedly supports far fewer MCU's at the present. I could have just used that rather than bothered to implement my own Cortex-M Forth, but I wanted to create my own Forth environment which I could play with as I saw fit (e.g. adding preemptive multitasking and other multitasking supports such as locks and channels).

Cool. Here are some other resources that I've encountered along the way of learning Forth:

- JonesForth: https://github.com/nornagon/jonesforth/blob/master/jonesfort...

This is legit a text that goes the an x86 Forth implementation. Actually, it's just an implementation with really extensive comments. That said, including whitespace and comments, it's just 2000 lines and the pedagogy is excellent. Highly recommended for anyone who would rather see behind the curtain before picking up a larger text.

- SmithForth: https://dacvs.neocities.org/SF/

So, Smith decided to hand-write a Forth directly in x86-64 opcodes (well, the corresponding ascii hex bytes). It's incredibly slim and enlightening how you can bootstrap a language in just a couple hundred bytes or so.

This project actually inspired me to really learn the x86-64 architecture, so I ended up hand-decompiling the SmithForth binary instead of going through his commented implementation. Hand-decompilation is an absolutely fascinating exercise. You learn all about ELF structure, opcode encodings, and actually start to see the gaps where microarchitectural details shine through. Highly recommended for any hacker that really wants to grok low level details.

- Mecrisp: https://mecrisp.sourceforge.net/

An amazingly fast Forth implementation for MSP430, ARM, RISC-V, MIPS, and some FPGAs. This gave me one really nice understanding of Forth as

    A REPL into your hardware!

I've git-cloned JonesFORTH (https://github.com/nornagon/jonesforth/blob/master/jonesforth.S) and achieved to compile it (i.e. run make w/o an error. When I start the executable, it presents me with an empty line, and when I say BYE, it says PARSE ERROR: bye.

Is there any particular language you're looking for? I've found some languages hideous until I understood them and could appreciate their respective graces. Off the top of my head the I can think of a couple.

The first is Jones Forth (https://github.com/nornagon/jonesforth), start with jonesforth.S and move into jonesforth.f. I really enjoyed following along with it and trying my hand at making my own stack based language.

The other is Xv6, a teaching operating system from MIT (https://pdos.csail.mit.edu/6.828/2021/xv6.html), not all the code or implementations are top notch but it shows you non-optimized versions (just because they're simple and more readable) of different concepts used in OS design.

If you're interested in the embedded world, there is a really neat project I've been following that feels a more structured and safe (as in fault-tolerant) while still staying pretty simple (both conceptually and in the code itself): Hubris and Humility (https://hubris.oxide.computer/).

Very low hardware requirements, so basic industrial control at the level where you'd otherwise use an Arduino or so but on scavenged hardware. Forth is ridiculously simple to get an implementation running.

https://github.com/nornagon/jonesforth/blob/master/jonesfort...

Is a nice starting point. It's obviously not as compact as say 'Brainfuck' but it is far more versatile.

OP mentioned jonesforth, but linked to a nasm port of it. Which is probably good it’s just that the documentation in the comments with ascii art doesn’t look right on my screen. So here’s a more common repo: https://github.com/nornagon/jonesforth

Rip the asm macros for the basic FORTH words out of this and then embed them in a C binary, statically linked with your favourite libs for whatever task. Although I haven't tried this yet, I'm planning on doing it with ncurses for my own Roguelike. From there, if you can convert the function calls and your parameters down to raw numbers, you can send instructions to ncurses or whatever other API you like, directly from a FORTH stack.

or the mirror of this site in github: https://github.com/nornagon/jonesforth