subleq
16-bit SUBLEQ CPU running eForth - just for fun (by howerj)
bit-serial
A bit-serial CPU written in VHDL, with a simulator written in C. (by howerj)
| subleq | bit-serial | |
|---|---|---|
| 9 | 1 | |
| 52 | 109 | |
| - | - | |
| 4.6 | 6.7 | |
| 19 days ago | 2 months ago | |
| Forth | VHDL | |
| The Unlicense | MIT License |
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
subleq
Posts with mentions or reviews of subleq.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2024-04-03.
-
The ancient world before computers had stacks or heaps
I wrote a Forth interpreter for a SUBLEQ machine (https://github.com/howerj/subleq), and for a bit-serial machine (https://github.com/howerj/bit-serial), both of which do not have a function call stack which is a requirement of Forth. SUBLEQ also does not allow indirect loading and stores as well and requires self-modifying code to do anything non-trivial. The approach I took for both machines was to build a virtual machine that could do those things, along with cooperative multithreading. The heap, if required, is written in Forth, along with a floating point word-set (various MCUs not having instructions for floating point numbers is still fairly common, and can be implemented as calls to software functions that implement them instead).
I would imagine that other compilers took a similar approach which wasn't mentioned.
- Show HN: Computing with just one instruction – Forth on SUBLEQ
-
SUBLEQ eForth book
I've already posted about the implementation on Forth, but you might want to see how such a system is created in detail along with the design decisions and compromises. The source code can be freely viewed at https://github.com/howerj/subleq.
- Show HN: A single instruction computer running Forth
- Forth on a SUBLEQ (A One Instruction Set Computer)
- Forth Running on a One Instruction Set Computer
- Computing with Just One Instruction
bit-serial
Posts with mentions or reviews of bit-serial.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2024-04-03.
-
The ancient world before computers had stacks or heaps
I wrote a Forth interpreter for a SUBLEQ machine (https://github.com/howerj/subleq), and for a bit-serial machine (https://github.com/howerj/bit-serial), both of which do not have a function call stack which is a requirement of Forth. SUBLEQ also does not allow indirect loading and stores as well and requires self-modifying code to do anything non-trivial. The approach I took for both machines was to build a virtual machine that could do those things, along with cooperative multithreading. The heap, if required, is written in Forth, along with a floating point word-set (various MCUs not having instructions for floating point numbers is still fairly common, and can be implemented as calls to software functions that implement them instead).
I would imagine that other compilers took a similar approach which wasn't mentioned.
What are some alternatives?
When comparing subleq and bit-serial you can also consider the following projects:
swapforth - Swapforth is a cross-platform ANS Forth
Mako - A simple virtual game console
durexforth - Modern C64 Forth
lbForth - Self-hosting metacompiled Forth, bootstrapping from a few lines of C; targets Linux, Windows, ARM, RISC-V, 68000, PDP-11, asm.js.