Digital Audio Tape

Digital Audio Tape (DAT or R-DAT) is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a compact audio cassette, using 4 mm magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As the name suggests, the recording is digital rather than analog. DAT has the ability to record at higher, equal or lower sampling rates than a CD (48, 44.1 or 32 kHz sampling rate respectively) at 16 bits quantization. If a digital source is copied then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD MiniDisc, both of which use a lossy data reduction system.

Like most formats of videocassette, a DAT cassette may only be recorded and played in one direction, unlike an analog compact audio cassette.

Although intended as a replacement for audio cassettes, the format was never widely adopted by consumers because of issues of expense and concerns from the music industry about unauthorized digital quality copies. The format saw moderate success in professional markets and as a computer storage medium. As Sony has ceased production of new recorders, it will become more difficult to play archived recordings in this format unless they are copied to other formats or hard drives.