A modern Forth for the Feersum Technology MicroBeast.
(And by "modern" I means ANS Forth standard circa 1997!)
Here's it running on the target hardware:
The 1.x series releases were a bit bare-bones, but 2.0 adds some genuinely useful capabilities, such as a full Z80 assembler, custom wordlists, and CP/M file support.
V2.0.0 supports the following ANS Forth standard words:
| § | Module | antforth | Coverage |
|---|---|---|---|
| 6.1 | Core | 133 / 133 | 100% |
| 6.2 | Core Extensions | 14 / 46 | ~30% |
| 7.6 | Block | 0 | 0% (deferred) |
| 8.6 | Double-Number | 13 / 14 | ~93% |
| 9.6 | Exception | 4 / 4 | 100% |
| 10.6 | Facility | 1 / ~9 | ~10% |
| 11.6 | File-Access | 17 / 17 | ~95% (FILE-STATUS missing) |
| 12.6 | Floating-Point | 0 | 0% (deferred) |
| 13.6 | Locals | 0 | 0% (deferred) |
| 14.6 | Memory-Allocation | 0 | 0% (deferred) |
| 15.6 | Programming-Tools | 2 / 5 | ~40% (.S, WORDS — no SEE/DUMP/?) |
| 16.6 | Search-Order | 6 / 6 | 100% + ext |
| 17.6 | String | 1 / ~9 | low (MOVE only) |
In addition we have some words outside the standard:
| Word | Source | Origin / role |
|---|---|---|
SP@ SP! RP@ RP! |
stack_ops.asm |
fig-Forth-era stack-pointer access; common extension |
DPL |
outer_interpreter.asm |
fig-Forth-era double-precision parse state |
NUMBER? |
outer_interpreter.asm |
parsing helper |
CATCH-TOP |
exception.asm |
antforth ext — exception-frame chain head (CCD-2) |
INCLUDE-TOP |
exception.asm |
antforth ext — INCLUDE source-frame chain head (CCD-1) |
HLD |
pictured.asm |
pictured-output cursor USER variable (de-facto Forth) |
0x numeric prefix |
parser | C-style hex literal — antforth ext alongside Forth 2014 $ / # / % |
And a whopping 81 words in the assembler, which are a mix of opcode mnemonics with trailing comma
(LD, ADD, JP, CALL, RET, INC, DEC, RLC, etc.), structural words (CODE / END-CODE, LABEL / FIX),
pseudo-ops (DB, DW, DS, EQU), addressing-mode helpers ((), #, +D), and stack/flow
primitives (PUSH, POP, JR, NEXT,).
- Banked memory support, and other {Micro,Nano}Beast hardware specific words
- Co-operative multi-tasking and event handlers
- Local variable support
- VideoBeast / AudioBeast support
- Exception Extensions
- Floating Point wordset
- Turnkey compiler
- Object Oriented extensions (I have tracked down a copy of Dick Pountain's extremely rare book, but have yet to absorb it)
- non-Beastly targets
If you're thinking "there's not much modern about a 56 year old language on a 50 year old processor" then wait til you see how I implemented it using state-of-the-art agentic LLMs...
There's still plenty to do if you're the Human in the Loop tho:
