Quarter Inch Cartridge
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Quarter Inch Cartridge (or QIC) tape is a computer storage magnetic tape format used from the 1970s to the present. QIC is a linear tape format, and is frequently pronounced as quick or quick tape. A QIC tape is a rather rugged package of aluminum and plastic that holds two tape reels driven by belts. The tape wound on the reels is one quarter inch (1/4") wide and anywhere from 450 to 1000 feet long. Data is written to tape in linear tracks.
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[edit] Features of QIC
Using a belt drive means that the speed at which the belt was moved was equal to the speed at which the tape would move. This is in contrast to cassette tapes or DATs, which rely on spindles in the reels and which vary tape speed as the amount of tape on the reels changes. It also means that no tension is ever put on the tape: the belt is in contact with both reels, so the tape should maintain a neutral tension at all times.
The tape in a QIC is not physically attached to the reels; rather, a series of holes are punched through the tape to allow the drive to identify the end of the tape. QIC tapes should never be wound past this point, also unlike cassettes and DATs. If a defective drive were to wind a cartridge past this point the tape will come completely off of the reels and the cartridge becomes unusable, although it is a relatively simple matter to open the cartridge and rewind the tape around the reel.
The design of the QIC tape cartridge is very robust: the aluminium and plastic case is an eighth of an inch thick all around and can withstand abuse and impacts that will often damage other tape formats.
However, because the tape is belt-driven, seeking can eventually cause the belt to become unevenly tensioned. Thus, it is periodically necessary to "retension" the cartridge. This is accomplished by winding the tape from beginning to end and back in one operation, allowing the belt to equalize itself.
When the cartridge gets old the rubber band may not provide enough friction to turn the takeup spool smoothly. When this happens the tape will need to be replaced.
[edit] Generations
[edit] QIC Data Cartridge (DC)
The first QIC tape format was the 5.875 in by 3.875 in (150 x 99mm) Data Cartridge (DC) format with two internal belt-driven reels and a metal base. This was introduced in 1972 by 3M. Various QIC DC recording formats have appeared over the years, including:
- QIC-11: a four-track format giving 20 MB on a 450 ft DC300XL cartridge
- QIC-24: nine-track, 45 MB or 60MB on a 450 or 600 ft (DC600A) cartridge respectively
- QIC-120: 15-track, 125 MB on a DC600A
- QIC-150: 18-track, 150 MB, DC6150 cartridge
- QIC-525: 26-track, 525 MB on a 1000 ft DC6525 cartridge
Other QIC DC standards included the QIC-02 and QIC-36 drive interface standards. Later QIC DC drives usually used the SCSI interface.
[edit] QIC Mini Cartridge (MC)
Later, the smaller Minicartridge (MC) form-factor was introduced. This was 2.375 in by 3.125 in (61 x 80mm) size and was small enough to fit in a 3.5 in drive bay.
- QIC-40: 40 MB
- QIC-80: 80 MB
The QIC-40 and QIC-80 were designed to use the same controller as a standard floppy drive, with MFM or RLL encoding.
[edit] Travan (TR)
Travan is an evolution of the QIC Minicartridge format, sold for personal computer use. This version, developed by 3M, uses a longer and wider (8 mm) tape to give higher capacities.
| Format | Capacity (MB) | Speed (kB/s) | Tracks |
|---|---|---|---|
| QIC-80 | 80-500 | 62.5 | 28/36 |
| TR-1 | 400 | 62.5 | 36 |
| QIC-3010 | 340 | 62.5 | 40/50 |
| TR-2 | 800 | 62.5 | 50 |
| QIC-3020 | 670 | 62.5 | 40/50 |
| TR-3 | 1,600 | 125 | 50 |
| QIC-3080 | 1,200-1,600 | 125 | 60/72 |
| TR-4 | 4,000 | 1024 | 72 |
| QIC-3095 | 4,000 | 1024 | 72 |
| TR-5 | 10,000 | 1024 | 108 |
[edit] SLR
SLR is Tandberg Data's name for its line of high-capacity QIC Data Cartridge drives. As of 2005, Tandberg is the only manufacturer of SLR/QIC drives in the world. The largest SLR drive can hold 70 GB of data (140 GB compressed).
[edit] QIC-Wide
A variant from Sony that uses a wider .315 inch (8 mm) tape and increases the recording density. QIC wide drives are backwards compatible with QIC tapes.
[edit] QIC-EX
QIC Extra, a modification to support a longer tapes, and thus more data by the Verbatim Corporation, this was made possible by making the cartridges physically longer.
[edit] QIC-157
An interface standard for tape drives using the ATAPI (IDE) interface.
[edit] External links
| Magnetic tape data storage formats | ||
|---|---|---|
| Linear | Helical-Scan | |
| Three Quarter Inch (~19 mm) |
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| Half Inch (12.65 mm) |
UNISERVO (1951) - IBM 7 Track (1952) - IBM 9 Track (1964) - IBM 3480 (1984) - DLT (1984) - IBM 3590 (1995) - T9840 (1998) - T9940 (2000) - LTO Ultrium (2000) - T10000 (2006) |
Redwood SD-3 (1995) - DTF (19xx) - SAIT (2003) |
| Eight Millimeter (8 mm) |
Travan (1995) - IBM 3570 MP (1997) |
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| Quarter Inch (6.35 mm) |
QIC (1972) - SLR (1986) |
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| Four Millimeter (3.8 mm) |
DDS/DAT (1989) |
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| One Eighth Inch (3.18 mm) |
KC Standard, Compact Cassette (1975) - Datassette (1977) |
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| Stringy (1.58 - 1.9 mm) |
Exatron Stringy Floppy (1979) - ZX Microdrive (1983) - Rotronics Wafadrive (1984) |
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