The Nintendo 64DD (64DD Roku Yon Dī Dī ) ("DD" being short for "Disk Drive", and originally "Dynamic Drive") is a peripheral for the Nintendo 64 game console. It plugged into the N64 through the EXTension Port on the Nintendo 64's underside, and allowed the N64 to use proprietary 64 MB magneto-optical discs for expanded data storage. Although it had been announced before the launch of the N64, the 64DD's development was lengthy. It was eventually released in Japan when the console was in its twilight years. Scheduled for North American release in 2000, it was a commercial failure, and was never released outside of Japan.
The 64DD was announced at 1995's Nintendo Shoshinkai game show event (now called Nintendo World). One of the games that was featured for use with the 64DD was Creator, a music and animation program by Software Creations, the same people that made Sound Tool for the Nintendo Ultra 64 development kit. The game advertised that it could be implemented into other games, being able to replace textures and possibly create new levels and characters. However, there was no playable version of Creator available at Shoshinkai 1995. At E3 in 1997, Nintendo's main game designer, Shigeru Miyamoto, speculated that the first games to be released for the new system would be SimCity 64, Mario Artist, Pocket Monsters, and EarthBound 64.
However, the 64DD was delayed until its release in Japan on December 1, 1999. Nintendo, anticipating that its long planned-out disc drive peripheral would become acommercial failure, sold the system mainly through a subscription service called RANDnet and customers would continue to receive games through the mail as well. Only very limited quantities of the 64DD were made available through stores. As a result, the 64DD was only supported by Nintendo for a short period of time and only nine games were released for it. Most 64DD games were either cancelled entirely, released as normal Nintendo 64 games, or ported to the GameCube.