The Family Computer Disk System most commonly known as the Famicom Disk System is a peripheral for Nintendo's Famicom video game console and was released in Japan in 1986. It uses proprietary floppy disks called "Disk Cards" for data storage. The Disk System is connected to the Famicom by plugging a special cartridge known as the RAM Adapter into the system's cartridge port, and attaching that cartridge's cable to the disk drive. The RAM adapter contains an additional 32kb of RAM for temporary program storage, 8 KB of RAM for tile and sprite data storage, and an ASIC known as the 2C33. The ASIC acts as a disk controller for the floppy drive, and also includes additional sound hardware featuring a single-cycle wavetable-lookup synthesizer. Finally, embedded in the 2C33 is an 8KB BIOS ROM. The double sided Disk Cards have a total capacity of 112kb. Many games span both sides of a disk or a single disk contains a different game on each side. A few games use two full disks, totaling four sides. The Disk System is capable of running on six C-cell batteries or a compatible AC adapter.