Nintendo 64 Dynamic Drive

First announced in 1997, then released exclusively in Japan on December 15th 1999, the Nintendo 64 DD is an add-on for the Nintendo 64 that uses writable magnetic (not magneto-optical) disks, similar to Zip Disks, to store game data. The peripheral attaches to the base of the Nintendo 64 in the Expansion Bay, similar to how the Famicom Disk System attached to the Famicom. Each game disk holds 64 megabytes of data with up to 38 megabytes writable space. These disks are cheaper to produce than cartridges and allow games to be saved to them - something that could previously only be done on cartridge games if they had (expensive) battery back-up or with the use of memory packs, and even these methods could not hold as much information as a 64 DD disk. While the disks don't hold as much data as CD-ROMs (650+ MB),