Released on February 21, 1986 in Japan at a cost of 15,000 yen, the Famicom Disk System was a drive add-on for Nintendo's Famicom that utilized proprietary yellow disks with a data capacity of 64k per side. Designed as a way to make games larger and cheaper, the system sold over four million units before it was discontinued.
Throughout 1986 and most of 1987, Nintendo published all of their games in Japan on disk only, and such well-known classics as The Legend of Zelda, Castlevania, and Metroid were originally released exclusively on the Famicom Disk System. Software for the system could be obtained in two ways: by taking a 2000 yen blank disk to one of thousands of Disk Writer kiosks around the country and paying 500 yen for a new game, or purchasing a complete game with packaging and a manual for about 3000 yen.
The system was initially a success, but as cartridges grew in size and fewer publishers were willing to tolerate Nintendo's strict licensing agreements for disk games, the number of releases dwindled. Still, close to 200 games were available by the time the last Disk Writers were removed from Japanese stores in 1993. And the system didn't die there. As of 2002, Nintendo was still copying games through the mail for those who sent in a disk and 500 yen. ~ Skyler Miller, All Game Guide