The 64DD is a magnetic disk drive peripheral for the Nintendo 64 game console developed by Nintendo. It was announced in 1995, prior to the Nintendo 64's 1996 launch, and after numerous delays was released only in Japan on December 1, 1999. The "64" references both the Nintendo 64 console and the 64MB storage capacity of the disks, and "DD" is short for "disk drive" or "dynamic drive".Plugging into the extension port on the underside of the console, the 64DD allows the Nintendo 64 to use proprietary 64MB magnetic disks for expanded and rewritable data storage, a real-time clock for persistent game world design, and a standard font and audio library for further storage efficiency. Its games and hardware accessories let the user create movies, characters, and animations to use within various other games and shared online. The system could connect to the Internet through a dedicated online service, Randnet, for e-commerce, online gaming, and media sharing. Describing it as "the first writable bulk data storage device for a modern video game console", Nintendo designed the 64DD as an enabling technology platform for the development of new genres of games and applications, dozens of which were in development for several years.
Only ten pieces of software were released until the unit was discontinued in February 2001, with 15,000 Randnet subscribers at the time. It was a commercial failure, with at least 15,000 total units being sold. Most games once planned for 64DD were released as standard Nintendo 64 games, ported to other consoles such as the GameCube, or canceled.
IGN summarized the 64DD as "an appealing creativity package" "targeted at a certain type of user" "that delivered a well-designed user-driven experience"—and a "limited online experiment at the same time", which partially fulfilled Nintendo president Hiroshi Yamauchi's "longtime dream of a network that connects Nintendo consoles all across the nation".