The Disk
The device is connected to the Famicom console by plugging its RAM Adapter cartridge into the system's cartridge port, and attaching that cartridge's cable to the disk drive. The RAM Adapter contains 32 kilobytes (KB) of RAM for temporarily caching program data from disk, 8 KB of RAM for tile and sprite data storage, and an ASIC named the 2C33. The ASIC acts as a disk controller, plus single-cycle wavetable-lookup synthesizer sound hardware. Finally, embedded in the 2C33 is an 8KB BIOS ROM. The Disk Cards used are double-sided, with a total capacity of 112 KB per disk. Many games span both sides of a disk and a few span multiple disks, requiring the user to switch at some point during gameplay. The Disk System is capable of running on six C-cell batteries or the supplied AC adapter. Batteries usually last five months with daily game play. The inclusion of a battery option is due to the likelihood of a standard set of AC plugs already being occupied by a Famicom and a television.