HP 1900ux - Manual (Page 78)

Glossary
78 HP StorageWorks 1000ux/1900ux/2300ux Optical Jukebox User’s Guide
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.