The Yamaha Music Disc Recorder MDR-1 was a floppy disk

Floppy disk

A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

 unit which could be attached to the FX/FS organs and digitally record and play back Electone

Electone

Electone is the trademark used for electronic organs produced by Yamaha.-History:After Hammond pioneered the electronic organ in the 1930s, other manufacturers began to market their own versions of the instrument...

 and Clavinova

Clavinova

The Clavinova is a long-running line of digital pianos created by the Yamaha Corporation. They are similar in styling to an acoustic piano, but with many features common to other digital pianos such as the ability to save and load songs, the availability of different voices, and, in more recent...

 performances.

Two models were produced:

• MDR-1A for the FX-1, and
• MDR-1B for the FX-10, FX-20, FS-20, FS-100, FS-30, FS-200, FS-50, FS-300, FS-70 and FS-500.

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

Kilogram

The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

.

It was later followed by the MDR-10.