The Family Computer Disk System(ファミリーコンピュータ ディスクシステムFamirī Konpyūta Disuku Shisutemu, sometimes abbreviated as the Famicom Disk System, Disk System, or simply FDS) was released on February 21, 1986 by Nintendo as a peripheral for the Family Computer (or Famicom) console in Japan. It was a unit that used proprietary floppy disks (called "disk cards") for data storage. It was announced, but never released, for the North American Nintendo Entertainment System. Through its entire production span, 1986-2003, 4.5 million units were sold.