I have a very unoptimized way to fill a rectangle on a C64 video screen with characters, as in a MOB (movable object) instead of a hardware sprite. It’s around 25 times faster than using Basic, and has “frame rate” of around 12 fps on a 50 Hz monitor. I’m sure it can be much faster. 👨‍💻

slide show of the several output screens of my program on the Commodore 64 that tests both a Basic and a machine language version