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. Image:Quarter-Inch Cartridges.jpg
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QIC
The first QIC tape format was the 5.875 in by 3.875 in 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.
Later, the smaller Minicartridge (MC) form-factor was introduced. This was 2.375 in by 3.125 in size and was small enough to fit in a 3.5 in drive bay. The QIC-40 and QIC-80 MC formats held 40 and 80 megabytes, respectively. They were designed to use the same controller as a standard floppy drive, with MFM or RLL encoding.
Pros and cons
Using a belt drive means that the speed the belt was moved at was equal to the speed the tape would move at. 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; the belt drive combined with punched holes to indicate an end-of-tape condition means that the tape should never be wound all the way to its end, also unlike cassettes and DATs. (This is not an advantage, per se, but in the event a broken drive winds a cartridge past its end, the cartridge becomes unusable, although it is a 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 eigth of an inch thick all around and can stand abuse and impacts that will turn most other tapes into very small pieces.
However, because the tape is belt-driven, seeking can eventually cause the belt to become unequally 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. If this happens the tape will probably be destroyed.
Travan
Travan is an evolution of the QIC Minicartridge format, sold for personal computer use. This version, developed by 3M, uses a longer and wider (8mm) 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 |
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 140 GB of data compressed (70 GB uncompressed).
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.
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.
QIC-157
An interface standard for tape drives using the ATAPI (IDE) interface.