Quarter Inch Cartridge

Quarter Inch Cartridge (or QIC) tape was a computer storage magnetic tape format from the 1970s to the present. QIC is a linear tape format, and is frequently pronounced as quick .

=QIC=

The first QIC tapes were full-size data cartridges with two internal belt-driven reels and a metal base. They were introduced in 1972. The QIC-40 and QIC-80 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 Compact audio cassette or Digital Audio Tapes, 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).

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.

=Travan=

An evolution of QIC is now sold for personal computer use. This version, called Travan and developed by 3M, uses a smaller mini cartridge .

=SLR=

The standard QIC tapes are also known as Scalable Linear Recording tapes. As of 2005, Tandberg Data 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 (Advanced Technology Attachment) interface.