A compact digital audio disc from Sony that comes in read-only and rewritable versions Introduced in late 1993, the MiniDisc has been popular in Japan The read-only 2 5in disc stores 140MB compared to 650MB on a CD, but holds the same 74 minutes worth of music due to Sony's Adaptive Transform Acoustic Coding (ATRAC) compression scheme, which eliminates inaudible portions of the signal
Minidisc is a relatively new digital media, out for about 8 years now It is a 2 5" square rewritable disc in a cartridge, so it's smaller than a CD, allows you to write to it many times over, and is better protected from scratches and whatnot It holds 74 minutes of audio, the same as a CDR, by way of a dynamic, psycho-acoustic compression algorithm called ATRAC ATRAC attempts to determine, in real-time, what frequencies the human ear should not be able to hear and eliminates them, making the file small enough to fit on the disc MD's use a magneto-optical phase-shift technique to make them re-writable - similar to CDRW
A compact data storage medium designed to store music MiniDiscs come in two varieties: playback only and recordable MiniDiscs can be recorded and played by MD4 See also Random Access, ATRAC, and MD DATA Disc