Try this Peet

BEGIN
RESET(serial); {9600, 8,N,1 at 11.0592Mhz, the word serial is optional}
WRITELN ('hello world'}
{If you use your own I/O this should be WRITELN (USER1,"text");}
END.

We have a lot of experience in writing SYS51 Pascal, and I have offered to rewrite the manual, but its still crap.

There is some neat "roll your own" I/O stuff hidden in IOdriver.asm too

If you want interrupt driven stuff, then I can possibly help with that too.
Steve