Good call! (Whether it's a directly threaded, indirectly threaded, subroutine threaded, token threaded, Huffman threaded, or string threaded call.)<p><a href="https://en.wikipedia.org/wiki/Threaded_code#Token_threading" rel="nofollow">https://en.wikipedia.org/wiki/Threaded_code#Token_threading</a><p>Mitch Bradley created OpenFirmware. It started at Sun as OpenBoot (informally "SunForth") on the SPARCstation 1 in 1989, was standardized as IEEE 1275-1994, and was renamed OpenFirmware at that time. Its lineage runs back through Mitch's earlier Forthmacs (Bradley Forthware, early 80s), which ran on 68k Macs, Sun-2/3, Atari ST, and Amiga. Mitch credits Henry Laxen and Michael Perry's F83 and Glen Haydon's MVP-Forth as the public-domain ancestors.<p>The metacompiler can target many platforms, word sizes, CPUs, and threading models, and produce stripped ROMable images. It can build the kernel as direct-threaded (DTC), indirect-threaded (ITC), subroutine-threaded (STC), or token-threaded (TTC), with 16, 32, or 64 bit cells. Shipping kernels are DTC native code with cell-sized xt pointers: 32 bit on the original SPARC and PowerPC machines, 64 bit on modern PPC64, SPARC64, and ARM64 builds.<p>Peripheral expansion cards ship a separate, portable, variable-byte token format called FCode. The kernel interprets FCode at boot/probe time and recompiles it on the fly into the live native dictionary. After probe, FCode-loaded drivers run as ordinary native Forth words. That two-stage design (fast native runtime, portable FCode transport) is what let Sun ship one card PROM image that worked across CPU generations.<p><a href="https://github.com/MitchBradley" rel="nofollow">https://github.com/MitchBradley</a><p><a href="https://github.com/MitchBradley/openfirmware" rel="nofollow">https://github.com/MitchBradley/openfirmware</a><p>FCode was designed for SBus on the SPARCstation 1, with cross-CPU portability built in. Sun's earlier and contemporary buses were not interchangeable with SBus (Sun-2 used Multibus, Sun-3 used VMEbus, the Sun386i "Roadrunner" used AT-bus), so the cross-architecture payoff arrived later, when IEEE 1275-1994 standardized OpenFirmware and PCI allowed FCode in option ROMs. After that, the same expansion-card PROM image could boot on Sun SPARC, Apple PowerPC Macs, IBM PowerPC servers (CHRP), and the OLPC XO.<p>Interview with Mitch Bradley (he's like the Woz of Forth):<p><a href="https://web.archive.org/web/20120118132847/http://howsoftwareisbuilt.com/2008/03/27/interview-with-mitch-bradley-firmware-olpc/" rel="nofollow">https://web.archive.org/web/20120118132847/http://howsoftwar...</a><p>In parallel with the OpenBoot work, Mitch also developed an extremely portable C-based Forth (the public version is "C Forth 93"). It runs a switch-threaded inner interpreter over packed tokens, with configurable cell width (16, 32, or 64 bit) and configurable token width (pointer-sized by default, 16 bit with the T16 build flag for tight flash budgets), plus a small hand-rolled FFI built around a fixed-arity 12-argument marshalling trampoline driven by a format string. It is now the embedded variant used in OLPC's OpenFirmware and in PlatformIO targets including RP2040, Teensy, ESP32, ESP8266, and STM32:<p><a href="https://github.com/MitchBradley/cforth" rel="nofollow">https://github.com/MitchBradley/cforth</a><p>OpenFirmware even has its own song:<p><a href="https://www.youtube.com/watch?v=b8Wyvb9GotM" rel="nofollow">https://www.youtube.com/watch?v=b8Wyvb9GotM</a><p>More on Mitch, OpenFirmware, and CForth:<p><a href="https://news.ycombinator.com/item?id=21822840">https://news.ycombinator.com/item?id=21822840</a><p><a href="https://news.ycombinator.com/item?id=33681531">https://news.ycombinator.com/item?id=33681531</a><p><a href="https://news.ycombinator.com/item?id=38689282">https://news.ycombinator.com/item?id=38689282</a>
I ran EForth under the Subleq from Howe R.J at <a href="https://github.com/howerj/muxleq" rel="nofollow">https://github.com/howerj/muxleq</a> (the subleq one) first at QuickJS (trivial tasks, almost a 1:1 map from the C code, made in a hurry) and under... jsinterp.py from the infamous yt-dlp but using arrays instead of printing functions. But... if yt-dlp's "mini-JS" implements some captcha input functions... you can add I/O with ease and run EForth with what they call (not me) a "Not totally functional interpreter".<p>Not totally... until people there run the 110 rule program, Conway's Life, Subleq+EForth...