Thanks Misfit, it looks very nice. Did you write it in BASIC or in a machine-code monitor on a real VIC, or maybe in assembly on a modern computer and cross-assemble it?
I'm getting my old VIC-20 up and running - just need a monitor cable - and I'd like to try developing on it like I did when I was a kid. Although I imagine cross-development with an emulator would be more comfortable.