Invented by Digital Equipment Corporation in 1984, this technique was acquired by Quantum Corporation in 1994.
A higher capacity variant was later developed as Super DLT (SDLT).
In terms of capacity, the DAT drives and the first DLT are equivalent. Nevertheless, DLT is characterized by a longer reading head life.
The readers have 6 guides to ensure that the tape is unwound. This allows an excellent contact between the magnetic tape and the read/write heads.
The data are written using each time two grouped tracks. The tape is divided into several parallel tracks. Each track uses the full length of the tape. When the head reaches the end of the tape, it resumes recording on the next track, but in the opposite direction.