Forth Computer Language for the 1st Forth Engine
In ten pages of source code Chuck Moore created cmForth (named after himself to distinguish this dialect from his FORTH, Inc.'s polyFORTH II). Completed in 1985 and run on the NOVIX 4000 gate NC-4000, cmForth was a single tasking minimalist development language booted from PROM into RAM and able to be recompiled by a two word (two lines of source code) Meta- Compiler which repointed the new program to another memory space so the programmer could jump back to the old version to modify code, recompile and execute the new version w/ turn-around time of a second or so. Three memory spaces supported by PROM and RAM on a printed circuit board provided Return Stack, Parameter Stack, Dictionary and a fourth memory space was dedicated to Input and Output. This Forth engine's gates performed the Forth instruction set of some 31 instructions and bypassed the need for microcode - cmForth was the first high level language to run on a processor designed to execute its instructions and my Forth Kit #1 ran at 4 MHz. Chuck said the optimising compiler could occasionally cause execution of four words in a single clock cycle.
The development environment started out as polyFORTH on an PDP-11, floppy disk and serial terminal. After the NOVIX Forth Engine was up and running cmForth, two I/O lines (+ ground) were bit-banged to talk and listen to the host '11.
cmFORTH source code was distributed w/ Computer Cowboys' Forth Kit on PROM in ASCII and with a printed listing.
Later a floppy disk driver was added; Ting published its source code in the "Steps In An Empty Valley" series of some 20+ Offete Press publications.
Other programmers in the community modified this system and called it B-Forth ("B" for beta) and E-Forth ("E" for embedded) to run on Intel chips.
My first public domain contribution to the Forth Interest Group (fig) community was the Shadow block documentation to cmForth's Source code - distributed by Chuck's Computer Cowboys company and also published by Ting. - Jay Melvin jMelvin AT infopath.com
