itsy-linux

Unix (Linux & MacOS X) port of itsy Forth by John Metcalf

John Metcalf (http://www.retroprogramming.com/) implemented minimal forth system:

• http://www.retroprogramming.com/2012/03/itsy-forth-1k-tiny-compiler.html
• http://www.retroprogramming.com/2012/04/itsy-forth-dictionary-and-inner.html
• http://www.retroprogramming.com/2012/04/itsy-forth-primitives.html
• http://www.retroprogramming.com/2012/06/itsy-forth-compiler.html
• http://www.retroprogramming.com/2012/09/itsy-documenting-bit-twiddling-voodoo.html

Resulting binary has very impressive size (978 bytes on Linux) and can be used to bootstrap a complete Forth system.

Original itsy code is producing .com files and can be found in "msdos" directory of this repository.

kt97679 ported it to 32-bit linux code. DylanMc ported it to MacOS (also 32 bit). Should move to any BSD pretty easily.

Sample session:

$ make
nasm itsy-linux.asm -fbin -l itsy-linux.lst -o itsy-linux
chmod +x itsy-linux
$ ./itsy-linux 
: say_hi 72 emit 105 emit 33 emit 10 emit ;
say_hi
Hi!
^C
$ 

TODO:

• get string literals going
• implement string operations, like ."
• implement number->string
• implement .
• if then
• do .. loop