Among those are the 1802, some 8-bit PICs, and the 6502 at the heart of the Commodore 64. That’s not to say ... Don’t have a C64? Build one.
Even other Commodore 64 mods, like the Raspberry Pi C64 expansion cartridge playing Doom, may be more practical for end users than 8x8 pixel AI sprite generation running on 40-year-old PC hardware.
Once upon a time, you might have developed for the Commodore 64 using the very machine itself ... You can always truck your builds over to an actual C64 when you’ve worked the bugs out!