Glossary

optical disk

A term synonymous with the 5.25-inch optical disk. There are two types of optical disks: rewritable and WORM.

optical disk library

See jukebox.

rewritable optical

An optical disk technology in which data can be repeatedly written using optical reading and writing technology.

SCSI

An acronym for the Small Computer Systems Interface.

storage slot

An autochanger element that holds cartridges when the cartridges are not in a drive or not being ejected through the mailslot.

terminator

A resistor array device used for electrically terminating a SCSI bus. A SCSI bus must be terminated at its two physical ends. A peripheral device uses a terminator only if it is at the end of the bus.

ultra density optical

UDO (Ultra Density Optical), like HP's DVD+RW, uses Phase Change technology in order to achieve increased data density on a 130mm disk. Phase Change technology uses a laser to read and write from the active layer on the disk. The recording process uses the laser to heat each data bit to a specific temperature. One temperature allows the bit to form a crystalline (reflective) mark and a different temperature allows the bit to form an amorphous (less reflective) mark. Data is read by using a low power laser beam to detect the difference in the levels of reflectivity recorded on the disk.

write-once or WORM

An additional operating mode available with multifunction drives. When a write-once (WORM) disk is inserted, the drive will write data, but will not write over data that has been previously written. This feature is useful for applications that need permanent data security and audit trails.

write-protect

A feature that prevents data from being written to a disk. A write-protect tab is located on both sides of the optical disk cartridge to enable write-protection on one or both surfaces of the disk.