Design
Tape drives can range in capacity from a few megabytes to hundreds of gigabytes of uncompressed data.
As some data can be compressed to a smaller size than the files on hard disc, it has become commonplace when marketing tape drives to state the capacity with the assumption of a 2:1 compression ratio; thus a tape with a capacity of 80 GB would be sold as "80/160". The true storage capacity is also known as the native capacity or the raw capacity. IBM and Sony have also used higher compression ratios in their marketing materials. The compression ratio actually achievable depends on the data being compressed. Some data has little redundancy; large video files, for example, already use compression technology and cannot be compressed further. A sparse database, on the other hand, may allow compression ratios better than 10:1.
Tape drives can be connected to a computer with SCSI (most common), Fibre Channel, SATA, USB, FireWire, FICON, or other interfaces. Tape drives are used with autoloaders and tape libraries which automatically load, unload, and store multiple tapes, increasing the volume of data which can be stored without manual intervention.
Some older tape drives - such as the DECtape, the ZX Microdrive and the Rotronics Wafadrive - were designed as inexpensive alternatives to disk drives which were at the time very expensive. However, modern tape drives that used advanced techniques like multilevel forward error correction, shingling, and linear serpentine layout for writing data to tape, along with lower disk drive prices, have made such alternatives obsolete.
Read more about this topic: Tape Drive
Famous quotes containing the word design:
“To nourish children and raise them against odds is in any time, any place, more valuable than to fix bolts in cars or design nuclear weapons.”
—Marilyn French (20th century)
“Westerners inherit
A design for living
Deeper into matter—
Not without due patter
Of a great misgiving.”
—Robert Frost (1874–1963)
“Nowadays the host does not admit you to his hearth, but has got the mason to build one for yourself somewhere in his alley, and hospitality is the art of keeping you at the greatest distance. There is as much secrecy about the cooking as if he had a design to poison you.”
—Henry David Thoreau (1817–1862)