Glossary

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1f: The lower operating frequency of a rotating memory device. In a single density systems it corresponds to all clock and not data bits.

2f: The higher operating frequency of a rotating memory device. In a double density systems it corresponds to clock and data bits in each bit cell.

Audio CD: CD format designed to hold audio data

Autoloader: Automated CD or DVD duplicator

Betacam: 1/2" tape format

Beta SP: Video tape format

Bit: As applied in magnetic recording, it represents one recorded information cell ("bit" is a contraction of "Binary" and "Digit" to define a unit of information).

Bit cell time: The average bit duration during the process of recording at continuous maximum flux reversal rates

Bit density: Bits per unit length, are or volume of the recording medium; for example, the number of bits per square centimeter of magnetic tape.

Bit error rate (BER): The fraction of bits that are in error. BER = e/N where e is the number of errors and N is the total number of bits (correct bits plus erroneous bits).

Bit: shift Also called peak shift. A shift in the detected signal peak caused by the influence of a neighboring flux transition.

Blu-ray: A Blu-ray Disc (also called BD) is a high density optical disc format for the storage of digital information, including high-definition video. Our blu-ray duplicator range..

Blue Book: standard for CD Extra

BPS: Bits per second

Bulk eraser: a device for the erasure of recorded signals on magnetic media. A strong alternating magnetic field is used to remove the signal. Also known as a degausser.

CD: Compact Disc, an optical disc used to store digital data, originally developed for storing digital audio.

CD-Bridge: CD format that includes extra information on a CD-ROM/XA track, so that it can be played on a CD-i or CD-ROM/XA drive

CD-DA: Compact Disc - Digital Audio

CD-Extra: a multisession CD featuring audio and data

CD-I: Compact Disc - interactive. A multimedia CD format

CD-R: Optical disc which data/audio can be written to once

CD-ROM: Compact Disc Read-Only Memory. An optical disc holding computer data.

CD-ROM/XA: CD-ROM Extended Architecture

CD-RW: A re-writable optical disc

CD Writer/Burner: A drive capable of writing and/or re-writing recordable CDs

CD DVD Printer: A printer capable of printing direct onto CD DVD discs

Certification: The process during manufacture of detecting and removing from the diskette defects which may cause data errors.

Coercitivity: the strength with which magnetic particles resist change

Coercivity or coercive force: The field strength required to bring the flux density to zero in a magnetic material

Computer Reel: magnetic tape wound on a real; used to store computer data

Cookie: the coated circular diskette that has been punched to its final shape, but has not been sealed in its jacket.

D1, D2: Digital Video Master Cassettes

DAT: Digital Audio Tape

dB: decibel

DCRS: Digital cassettes

decibel: A dimensionless unit for expressing the ratio of two powers, or more usually voltages or currents, on a loge=arrythmic scale. If A and B represents two voltages or currents the ratio A/B corresponds to 20 log A/B decibels. One decibel represents a ratio of approximately 1.1 to1 between A and B

degauss: to demagnetize; for example, demagnetizing video tape to completely erase the data. To return the magnetization in a media coating or in a head to a zero state by applying a decaying and alternating magnetic field

degaussing: degaussing or demagnetizing describe the use of an external degausser or bulk eraser erase data from magnetic media. Our Degausser range..

DDS: Digital Data Storage tape

Disk/Diskette: Removable magnetic media storage, usually 3.5" square

diskette: A flexible, circular substrate made of polyester, coated on one or both sides with magnetic oxide, ands designed to re4ceive and store electrically coaded information for later retrieval.

DVC Pro: Digital Video tape

D-VHS: Digital Video Home System

DVD: Digital Versatile Disc. Most DVDs are of the same dimensions as compact discs (CDs) but store more than six times as much data.

DVD Audio: DVD format designed to hold audio data

Disk-At-Once (DAO): a whole CD is written to without turning the laser off, i.e. there is only one track burned.

DVD-R: Optical disc capable of having data written onto it once. Much larger capacity than CD-R.

DVD-ROM: Digital Versatile Disc Read-Only Memory. Holds computer data

DVD-RW: A re-writable DVD disc

DVD Video: DVD format designed to hold video data

EP: Extra Pulse Caused by minor media defects of contaminants on a disk when DC biased.

Exabyte: Tape cartridge manufacturer

FCI: Flux changes per inch

Firmware: instructions and data programmed into the circuits responsible for controlling the operation of peripheral devices

Flippy: A diskette which has been certified on both sides to be 100 percent error-free and thus able to be "flipped" over for use on either side.

Floppy: The term used to describe a diskette's characteristic flexibility when free of its protective jacket

Flux: Lines of magnetic force

Formatted capacity: The maximum amount of data bytes that can be stored on the media

Green Book: standard for CD-I

Hard error: An error that is repeatable in the same track and sector location

HD DVD: High-Definition Digital Versatile Disc is a high-density optical disc format designed for the storage of data and high-definition video

HFS: Mac OS Standard File System

Hi-8: High-density camcorder tape

High energy tape: magnetic tape having coercivity higher than 600 Oersteds

Hybrid CD: CD-ROM standard readable by PCs and MACs

ISO9660: The industry standard file structure for CD-ROMs

Joliet: Joliet file system

kBPS: Kilobits per second

Lightscribe: an optical disc recording technology that utilizes specially coated recordable CD and DVD media to produce laser-etched labels with text or graphics. Our lightscribe printer/burner..

Magnetic flux: The magnetic lines of force produced by a magnet for electric current

Magnetic field strength: The magnitude of a magnetic field vector, usually expressed in oersteds or ampere-turns per meter.

Master: A disc or file containing data or audio ready for duplication

Maxwell: A unit of magnetic flux

Mixed Mode: a format including a data track and one or more audio tracks

MMF: magnetomotive force The magnetic analogue of electromotive force, which, when due to a current in a coil, is proportional to the product of current in amperes and the number of turns.

MP: Missing Pulse. Caused by minor media defects or contaminants on the surface of a disk.

MTBF: Mean Time Between Failures. A measure of how reliable a piece of hardware or a component is.

Multisession: recordable CD format allowing data to be written to the disc in more than one session

Oersted: a cgs unit of magnetic field strength, symbol: Oe

Optical Disc Drive (ODD): a disk drive that uses laser light or electromagnetic waves near the light spectrum as part of the process of reading and writing data.

Orange Book: a recordable CD standard; CD-R and photo CD

Overwrite: Overwrite of an FMM (digital) recording with the two frequencies 1f and 2f is defined as the ratio of the original 1f (of half band edge signal) to that remaining after being overwritten with 2f (or band edge signal). Overwrite of 30 dB is considered adequate for proper system performance.

Overburning: is the process of recording data past the normal size limit of the optical disc.

Pancake: tape spooled on a hub in a pancake shape

Photo CD: process from Kodak whereby images from film are stored onto a CD

QIC: Quarter-Inch Cartridge Drive standard

Red Book: standard for CD-Rs playable in audio CD players

Retentivity: The maximum value of the residual flux density corresponding to saturation flux density.

Rockridge: Rockridge file system

S-VHS: Super Home Video System

TK50/TK75: tapes for TK50/TK75 tape cartridge system

TPI: Tracks per inch

Table of Contents (TOC): Information on the starting postions of tracks in the area of the CD before audio or data

Tower: Manual CD or DVD duplicator. Our PowerTower range..

Track: That portion of a recorded surface available to one read/write head at each access position. Also an area of tape surface that coincides with the location of the recorded magnetization produced by one record gap.

Track-At-Once (TAO): when the CD is written the laser is turned on and off between tracks, leaving a small gap between audio tracks

Travan: Type of data cartridge

U-matic: 3/4" tape format

UFS: Unix File System

VHS: Video Home System. VHS tapes are often used in consumer Video Cassette Recorders (VCRs) and in CCTV systems.

Video CD: CD format designed to hold video data

White Book: standard for Video CD

Yellow Book: CD-ROM standard