Commodore 64 BASIC: Sprites on the border (no machine language)

An attempt at implementing the border hack to show sprites offscreen. Line 50 makes it work: by WAITing on the raster interrupt (bit 0 of 53273). Note that the interrupt status register (53273) always works, even if the IRQ pin isn't unmasked/enabled at 53274; you can poll it anytime. It takes experimentation to find which scanline to trip it on, because of the time the BASIC interpretation takes. (This was done easily enough by temporarily substituting 53265 with 53280, so you can see what you're doing.) BASIC isn't fast enough to do anything beyond the main loop in line 50. The 1/60 interrupt from the first CIA is also turned off, to prevent interference.

Видео Commodore 64 BASIC: Sprites on the border (no machine language) канала Aqui De Rossi