Nintendo 64DD
The Nintendo 64 Disk Drive (ニンテンドウ64DD, Nintendō Roku Jū Yon DD) was a peripheral released for the Nintendo 64 in Japan. It plugged into the EXTension port at the bottom of the Nintendo 64 console and allowed for the use of magnetic disks containing games, extra content, or extra memory. The Nintendo 64 DD was released late in the console's lifespan and was a commerical failure.
As the Nintendo 64 DD sold few units, only nine games overall were released. An expansion for The Legend of Zelda: Ocarina of Time was planned under the working title of Ura Zelda, but was eventually shelved. Later, however, The Legend of Zelda: Ocarina of Time Master Quest was developed and released for the Nintendo GameCube, utilizing the same concepts originally intended for Ura Zelda.
See also: Nintendo 64DD on 