software came on rom cartridges. it has a membrane keyboard, 2 kib of ram and 0.5 kib of color ram (1024 × 4 bits). a television is used as a display. the commodore 64 has the same chipset, 6510 cpu and sid sound chip, and has a compatibility mode, which was often used for "freezer" cartridges, such as the action replay, to easily allow control of the running program. tape drives (for storage) worked, but not disk drives, printers or modems due to not having the right serial and user ports.