Minidisc

MiniDisc

The Sony MZ1 was the first MiniDisc player, released in 1992.
Media type	Magneto-optical disc
Encoding	ATRAC, linear PCM (with Hi-MD)
Capacity	80 min (standard MiniDisc), up to 45 hours of audio (1 GB capacity) (with Hi-MD)
Read mechanism	780 nm laser
Write mechanism	Magnetic field modulation
Developed by	Sony
Usage	Audio storage, Data storage (with Hi-MD)

The MiniDisc (MD) is a magneto-optical disc-based data storage device offering a capacity of 74 minutes and, later, 80 minutes, of digitized audio or 1 gigabyte of Hi-MD data. The Sony brand audio players were on the market from September 1992 until March 2013.

MiniDisc was announced by Sony in September 1992 and released that November for sale in Japan and in December in Europe, Canada, the USA and other countries . The music format was originally based exclusively on ATRAC audio data compression, but the option of linear PCM digital recording was later introduced to attain audio quality comparable to that of a compact disc. MiniDiscs were very popular in Japan but made a limited impact elsewhere.

Sony announced they would cease development of MD devices, with the last of the players sold by March 2013.

In 1983, just a year after the introduction of the Compact Disc, Immink and Braat presented the first experiments with erasable magneto-optical Compact Discs during the 73rd AES Convention in Eindhoven. It took, however, almost ten years before their idea was commercialized.

Sony's MiniDisc was one of two rival digital systems, introduced in 1992, that were both targeted as a replacement for the Philips analog cassette audio tape system: the other was Digital Compact Cassette (DCC), created by Philips and Matsushita. Sony had originally intended for Digital Audio Tape (DAT) to be the dominant home digital audio recording format, replacing the analog cassette. Due to technical delays, DAT was not launched until 1989, and by then the U.S. dollar had fallen so far in relation to the yen that the introductory DAT machine Sony had intended to market for about $400 in the late 1980s now had to retail for $800 or even $1000 to break even, putting it out of reach for most users.