Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Quarter inch cartridge tape (abbreviated QIC, commonly pronounced "quick") is a magnetic tape data storage format introduced by 3M in 1972, with derivatives still in use as of 2009. QIC comes in a rugged enclosed package of aluminum and plastic that holds two tape reels driven by a single belt in direct contact with the tape. The tape was originally 1/4-inch (6.35 mm) wide and anywhere from 300 to 1,500 feet (91 to 460 m) long. Data is written to tape in linear tracks in what is called "serpentine" mode, where the tracks alternate direction by use of a head switch or step. Since the introduction of the format, QIC has been widely used and many variations exist.