Back in the 1980's I had a TRS-80 color computer which was running a Unix-clone operating system called OS-9, this was multi-tasking and multi-user so I could log into my Coco with a DEC Correspondent printing terminal.
I wrote a FORTH implementation for the 6809 in about 3k lines of assembly code which included the language plus the 'standard library'. Instead of the 'standard' Forth I/O, there was an interface to Unix-style file-handle based I/O. It used subroutine threading so that FORTH compiled directly to 6809 code and the part that did dynamic dispatch used self-modifying code to shave off a few cycles.
FORTH is an interesting part of the story about why LISP didn't take off on 1980's microcomputers, partly because if you wanted a LISP on an 8-bit micro, you could get much of the way there with FORTH in a footprint even smaller than BASIC.
Comments
Back in the 1980's I had a TRS-80 color computer which was running a Unix-clone operating system called OS-9, this was multi-tasking and multi-user so I could log into my Coco with a DEC Correspondent printing terminal.
I wrote a FORTH implementation for the 6809 in about 3k lines of assembly code which included the language plus the 'standard library'. Instead of the 'standard' Forth I/O, there was an interface to Unix-style file-handle based I/O. It used subroutine threading so that FORTH compiled directly to 6809 code and the part that did dynamic dispatch used self-modifying code to shave off a few cycles.
FORTH is an interesting part of the story about why LISP didn't take off on 1980's microcomputers, partly because if you wanted a LISP on an 8-bit micro, you could get much of the way there with FORTH in a footprint even smaller than BASIC.