Actually, the Atari 2600 runs a 6507 which is a cheaper version of a 6502. Unlike the 64kbytes a 6502 can address, the 6507 is limited to 8kbytes. Worse, the

Actually, the Atari 2600 runs a 6507 which is a cheaper version of a 6502. Unlike the 64kbytes a 6502 can address, the 6507 is limited to 8kbytes. Worse, the cartridge design limited you to 4kbytes unless you bank switched. But that was storages, which was huge compared to the 128 bytes of RAM. Further complications happen because you need to time things with the scan lines of the display.