Digital Linear Tape (DLT) is considered a de facto standard for magnetic tape technology used for computer data storage. It was invented by Digital Equipment Corporation in 1984, and was purchased by Quantum Corporation in 1994, who currently manufactures drives and licenses the technology and trademark.

A variant with higher capacity is called Super DLT (SDLT). The lower cost value line was initially manufacured by [http://www.4benchmark.com Benchmark Storage Innovations]. Quantum acquired Benchmark in 2002.

DLT uses linear serpentine recording with multiple tracks on half-inch (12.6 mm) wide tape. SDLT adds an optical servo system that reads servo patterns on the back of the tape. DLT7000 and 8000 tilt the head forward and backward to reduce crosstalk between adjacent tracks through azimuth; this is called Symmetric Phase Recording.

The cartridges contain a single reel and the tape is pulled out of the cartridge by means of a leader tape attached to the takeup reel inside the drive. The drive leader tape is buckled to the cartridge leader during the load process. Tape speed and tension are controlled electronically via the reel motors; there is no capstan. The tape is guided by 4 to 6 rollers that touch only the back side of the tape. Tape material is metal particle tape (MP/AMP.)

Media are guaranteed for 30 years of data retention under specified environmental conditions; however, they are easily damaged by mishandling (dropping or improper packaging during shipment.)

Current manufacturers of cartridges for the DLT/SDLT market are Fujifilm, Hitachi/Maxell and Imation. VStape is made by Sony. All other companies/brands (even Quantum) are contractors and/or resellers of these companies.

All (S)DLT drive support hardware data compression. The often-used compression factor of 2:1 is optimistic and generally only achievable for text data; a more realistic factor across a file system is 1.3:1 to 1.5:1.

A new naming convention took effect in 2005, calling the performance line DLT-S and the value line DLT-V.

Drives:

Media:

Tapes written in value series drives can typically be read (and often written) in higher end drives of a similar vintage. Check the specs for your specific drive to find out its interoperability options.