El disco
For its proprietary diskette platform, which they dubbed the "Disk Card", Nintendo chose to base it on Mitsumi's Quick Disk media format, a cheaper alternative to floppy disks for Japanese home computers. The Disk Card format presented a number of advantages over cartridges, such as increased storage capacity that allowed for larger games, additional sound channels, and the ability to save player progress. The add-on itself was produced by Masayuki Uemura and Nintendo Research &amp; Development 2, the same team that designed the Famicom itself. Following several delays, the Famicom Disk System was released on February 21, 1986, at a retail price of ¥15000 (US$80). The same day, Nintendo released "The Legend of Zelda" as a launch title, alongside disk re-releases of earlier Famicom games. Marketing material for the Disk System featuring a yellow mascot character named Diskun, or Mr. Disk. The Famicom Disk System sold over 300,000 units within three months, jumping to over 2 million by the end of the year. Nintendo remained confident the Disk System would be a sure-fire success, and ensured that all future first-party releases would be exclusive to the peripheral.