digital audio tape (DAT)
DigitalAudio Tape (DAT) is the name given to a 4 mm wide magnetic tape that was designed for high-quality audio recordings but, due to its high storage capacity, has also found its way into data processing as a storage medium for backup applications and is mainly used in medium-sized industry.
For storing audio signals, DAT works with sampling rates of 48 kHz, 44.1 kHz and 21 kHz and a sampling depth of 16 bits, which corresponds to a data rate of 1.536 Mbit/s for 48 kHz digitization.
Based on the DAT standard, Sony and Hewlett Packard developed an industry standard for data storage, Digital Data Storage( DDS). The first DAT drives based on the DDS standard were introduced in 1989. At that time, the storage capacity was 1.3 gigabytes( GB), and the maximum data transfer rate was 183 kB/s.
In the meantime, there have been several drive generations with storage capacities between 4 GB and 320 GB of compressed data. DAT uses the helical-scan method ofrecording, which works with rotating head drums. The data transfer rate ranges from 6 MB/s, depending on the version.
To prevent DAT tapes for audio from being used as streamer tapes and vice versa, a bar code, Media Recognition System( MRS), is attached to the beginning of the streamer tapes. This allows audio DAT cartridges to be used for audio only and streamer cartridges to be used for data storage only.