D/CAS (Data/CASsette), also known as a streamer cassette, is a now-obsolete data backup technology that used an upgraded version of the common audio cassette tape and a specialized

tape drive A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic tape data storage is typically used for offline, archival data storage. Tape media generally has a favorable unit cost and a long archival stability. ...

derived from an audio tape

transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...

. Holding anywhere from 200 KB to 600 MB (in 1990), it was superseded by newer data backup formats such as

Travan Travan is an 8 mm magnetic tape cartridge design developed by the 3M company, used for the storage of data in computer backups and mass storage. Over time, subsequent versions of Travan cartridges and drives have been developed that provide gr ...

, QIC, DDS, and LTO. Streamer cassettes look almost like a standard audio cassette, with the addition of a notch about one quarter inch wide and deep, situated slightly off-center at the top edge of the cassette. They also have a reusable write-protect tab on one side of the top edge, with the other side having either only an open rectangular hole, or no hole at all. Data was recorded across four tracks in a serpentine manner across the whole width of the tape, much like newer formats such as QIC or Travan, making them single-sided. Streamer cassettes can be used in an audio cassette deck, but the formulation of tape they contain is optimized only for full-saturation square wave digital data, resulting in audio recordings made on them having very poor audio quality and a large amount of noise and distortion.

Sources

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Museum of Obsolete Media's page on streamer cassettes
Backup {{Compu-storage-stub

See also

Sources