In 1983, there weren't many portable music options. The Walkman had only been out for a few years, CDs were just in their infancy, and most people owned a large collection of records. Audio Technica's Mister Disc was designed to fill this void.
What probably seemed like a great idea turned into a flop. They're almost impossible to find now, even on ebay (here's an old listing). I guess us 80s kids just weren't cool enough to see the intrinsic greatness in the Mister Disc.
via Soul Express Radio