In 1980 Mark Rustad ported the Pascal-M compiler, with the help of Brian Hanson for the 6809 interpreter, to the Flex operating system.
The compiler of 1978 was extended with:
– the VALUE statement: initialize values
– Reset, Rewrite and I/O for files
Here the sources of compiler (in Pascal) and interpreter (in 6809 assembler for Flex) and some utilities and programs like a Lisp interpreter.
http://pascal.hansotten.com/uploads/pascalm/flex6809/pacalm6809.zip