Tagged: linear

Travan (1995 – 2002)

Travan is a magnetic tape format based on QIC and introduced by 3M in 1995. Although based on QIC (Quarter Inch Cartridge), Travan tapes use 8mm wide tape of 750 feet. The tape is not attached to the hubs, and is prevented from coming off at the ends using small holes punched in the tape, which are detected by optical sensors in the tape drive using a 45-degree mirror inside and a window on the side the cartridge.

There have been several generations of Travan, beginning with TR-1 that had a capacity of 400 MB on 36 tracks, to TR-7 with 20 GB capacity on 108 tracks.

Travan technology does not automatically verify data after writing, and this must be done separately otherwise it is possible for backups to be found to be corrupt and unusable when the tapes need to be used.

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IBM Magstar MP 3570 (1996 – 2002)

IBM Magstar MP 3570The IBM Magstar MP 3570 was a magnetic tape cassette format introduced in 1996. It was designed for mid-range computer systems, for the tapes to be handled by automated tape libraries, and to have fast data access.

The format used 8mm wide metal particle tape with 128 tracks. The original tapes, called B-type, had a capacity of 5GB uncompressed. The follow-on C-type tapes had the same capacity, but were faster. The final tape media, called C-XL, had a capacity of 7GB uncompressed.

Slower tape formats with higher capacities proved more successful, and the IBM 3570 technology did not enjoy a large market penetration.

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IBM 3480 (1984 – 2004)

IBM introduced the 3480 tape cartridge format in 1984 for use on the IBM System/370 computers, to replace the existing 9-track tape reel format.

It consisted of a rectangular cartridge containing a single reel of ½-inch chromium dioxide tape. The take-up reel is inside the drive. By employing 18 recording tracks, data transfer was much faster than 9-track tape, and a cartridge could store 200 MB.

Various manufacturers made drives, and tapes were transferable between different manufacturer’s drives.

In 1986, hardware-based data compression allowed for 400 MB per cartridge, renamed as the IBM 3490. This was followed by the IBM 3490E format in 1991, employing 36 tracks, and allowing up to 2400 MB with hardware-based data compression.

The IBM 3480 family of formats was superseded by the IBM 3590 or Magstar family, and the last IBM 3480 family drives were manufactured in 2004.

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ZX Microdrive (1983 – 1987)

The ZX Microdrive was a magnetic tape data storage format introduced in 1983 by Sinclair Research for use with its ZX Spectrum home computer, and later used on the Sinclair QL and ICL One Per Desk computers as a cheaper alternative to floppy disk drives.

It used a cartridge with an endless loop of very narrow (1.9mm wide) tape with a maximum capacity of 85 KB (when formatted for use in a QL, this was increased to 100 KB). The loop was 5 metres in length, and a complete circuit took 8 seconds.

Blank and pre-recorded cartridges were available.

The Wafadrive was a similar format also marketed to ZX Spectrum owners.

The ZX Microdrive system gained a reputation for unreliability, one of the reasons being tape stretch which meant the cartridges had a short lifespan. When used with the QL and ICL One Per Desk, the system was modified to reduce tape stretch.

The Sinclair QL was discontinued in 1986, and by 1987, the ZX Spectrum +3 was introduced that had a built-in 3-inch floppy disk drive.

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IBM Magstar 3590 (1995 – )

IBM Magstar 3590 is the name of of the series of tape backup drives and their media, introduced by IBM in 1995.

Magstar 3590 media consists of a cartridge with a single reel of ½ inch magnetic tape that can store up to 60 GB of data on 634 m of metal particle tape on the Extended High-Performance cartridge (the High-Performance cartridge can store up to 30 GB on 320 m of tape). It replaced the IBM 3480 tape family.

Because of their speed, reliability, durability and low media cost, the Magstar 3590 tape drives are still in high demand.

Sources / Resources

IBM 3590 page on Wikipedia

Magstar page on ’50 Years of Storage Innovation’

Linear Tape-Open (LTO) (2000 – )

Linear Tape-OpenLinear Tape-Open (or LTO) is a magnetic tape data storage technology released in 2000, mainly used for backup. It was designed as a more open standard to compete with the DLT tape format.

Two versions of LTO were planned, but only the Ultrium version was released, using ½ inch tape in a single-reel cartridge. The first generation could contain up to 100 GB on a cartridge. The latest generation (version 6) released in 2012 can hold 2.5 TB.

The tape inside an LTO cartridge is wound around a single reel. The end of the tape is attached to a perpendicular leader pin that is used by the drive to grasp the end of the tape and mount it in a take-up reel. When a cartridge is not in a drive, the pin is held in place at the opening of the cartridge with a small spring.

Most manufacturers produced different generations of LTO cartridges in different colours, generally being 1) Black or gray, 2) Purple, 3) Blue-grey, 4) Green, 5) Dark red, 6) Black.

Every LTO cartridge has a memory chip inside it, with a total of 8 KB on newer generations. This is used to identify tapes, identify generations of tape, or store tape-use information.

Sources / Resources

Wikipedia entry for Linear Tape-Open

LTO3 Ultrium tape autoloader on YouTube

QIC Data Cartridge (1972 – 2000s)

QIC (Quarter Inch Cartridge) is a family of magnetic tape formats for data storage, using quarter inch tape.

The original QIC was known as a Data Cartridge and was introduced by 3M in 1972.

QIC is actually a cassette format, with two reels driven by a belt in contact with the tape, and enclosed in a robust plastic and aluminium housing. The use of a belt ensure constant speed for the tape, and neutral tension. Over time the tape can become unevenly tensioned, and a needs to be wound from beginning to end.

The tape is not attached to the reels, so if it is unwound beyound the optical end of tape markers it will become detached.

QIC Data Cartridges can hold anything between 200 KB and 25 GB.

The QIC International Trade Association was disbanded in 1998, after 15 million QIC Data Cartridge and Minicartridge drives had been installed.

Sources / Resources

Wikipedia entry for Quarter Inch Cartridge

QIC International Trade Association