The Yamaha Music Disc Recorder MDR-1 was a floppy disk unit which could be attached to the FX/FS organs and digitally record and play back Electone and Clavinova performances.
Two models were produced:
It used 3-inch compact floppy disks which could store 200 KB per side, at a maximum of nine programs.
It measured 190(W) x 273(D) x 109(H) mm and weighed 4.5 kg.
It was later followed by the MDR-10.