The PocketStation is a memory card peripheral made by Sony Computer Entertainment for the PlayStation that was released in Japan on January 23, 1999. It had a ARM7T CPU with 2KB of RAM. Software for the PocketStation was typically distributed as PlayStation CD-ROM extras, enhancing the games with added features. Stand-alone software could also be downloaded through the PlayStation console. The software is then transferred to the PocketStation for use. A built-in infrared data interface allows direct transfer of data such as game saves between PocketStation units, as well as multiplayer gaming. 60 games in total were compatible with the PocketStation.