- Author: Richard James Howe
- Email: mailto:howe.r.j.89@gmail.com
- Repo: https://github.com/howerj/subleq
- License: The Unlicense / Public Domain
If you feel like supporting the project you can buy a book from Amazon, available here that describes how the project works and how to port a Forth to a new platform.
This project contains a working (self-hosting) Forth interpreter that runs on top of a SUBLEQ 16-bit machine. SUBLEQ machines belong to the class of One Instruction Set Computers, they only execute a single instruction but are still Turing Complete. The Forth system, specifically a variant of eForth, is provided as subleq.dec, passing this image to the tiny (~ 600 bytes) SUBLEQ C virtual machine allows you to run eForth on the machine. For a list of commands type "words" and hit enter, numbers are entered using Reverse Polish Notation, eg. "2 2 + . cr" prints "4", and new functions can be defined like so:
: hello cr ." Hello, World" ;
Be careful with the spaces, they matter, after typing that in, type "hello" and hit enter. A Forth tutorial will not be provided here. Many Forth words are defined including the bitwise words.
To build and run you will need a C compiler and Make, type "make run", failing that:
cc subleq.c -o subleq
./subleq subleq.dec
The system is self hosting, that is it can generate new eForth images using the current eForth image and the eForth source code. This is done like so:
./subleq subleq.dec < subleq.fth > new-image.dec
There is a website available that runs an interactive SUBLEQ interpreter in the browser in case you do not want to both compiling things, it is available at https://github.com/howerj/subleq-js. Or if you just want to try it out directly https://howerj.github.io/subleq.htm.
Happy hacking, and a shiny penny for anyone that manages to do something useful with this project!
- https://github.com/pbrochard/subleq-eForthOS
- https://github.com/howerj/subleq-python
- https://github.com/howerj/subleq-perl
- https://github.com/howerj/subleq-js
- https://github.com/howerj/subleq-forth
- https://github.com/howerj/subleq-vhdl
- https://en.wikipedia.org/wiki/Forth_(programming_language)
- https://github.com/howerj/bit-serial
- https://github.com/howerj/embed
- https://github.com/howerj/forth-cpu
- https://rosettacode.org/wiki/Subleq
- https://stackoverflow.com/questions/2982729
- https://stackoverflow.com/questions/34120161
- https://web.ece.ucsb.edu/~parhami/pubs_folder/parh88-ijeee-ultimate-risc.pdf
- https://esolangs.org/wiki/Subleq
- https://wikipedia.org/wiki/Threaded_code
- https://github.com/samawati/j1eforth
- https://www.bradrodriguez.com/papers/
- 8086 eForth 1.0 by Bill Muench and C. H. Ting, 1990
- https://www.bradrodriguez.com/papers/mtasking.html, For multitasking support
- https://forth-standard.org/standard/block, For the block word-set, which is partially implemented.
- https://github.com/howerj/subleq-js
- URISC, the original OISC, a SUBLEQ machine: Mavaddat, F.; Parhami, B. (October 1988). "URISC: The Ultimate Reduced Instruction Set Computer".
- https://en.wikipedia.org/wiki/Turing_tarpit, which SUBLEQ could be argued to be one.
- For other Single Instruction Set Computers: https://en.wikipedia.org/wiki/One-instruction_set_computer
- For the Forth-83 Standard: http://forth.sourceforge.net/standard/fst83/ http://forth.sourceforge.net/standard/fst83/FORTH-83.PRN
- DPANS84 FORTH standard: http://forth.sourceforge.net/std/dpans/