Nobody knows why exactly, but my cartridge code is now alive. The problem is on the C64 side of things and mainly has to do with the routine that would copy my bootloader into a safe RAM location.

I replaced it with some very hardcore manual loading-and-moving instructions that would simply copy every instruction over one by one, and now it works. I added some very crude code for loading a KoalaPainter bitmap to bank 1 and managed to validated Kla2kick at the same time. 12Next up: draft a proper design on how to use this new-found sea of speedy ROM for a Larry game.