Thanks! I used CBM prg Studio for development. Very nice to use.
CBM Prg studio is great for development at assembler level for Commodore machines. If you ever want to try doing it in a bit more user-friendly language then perhaps have a look at TRSE. It's fantastic for working on Vic or C64 games :)
https://lemonspawn.com/turbo-rascal-syntax-error-expected-but-begin/