Glossary
DLT-V4 Product Manual
62
D
Data Compression
A process that reduces the amount of storage space required
to hold a particular block of data. Data transfer speed and total media capacity are
affected by the data compression achieved. In accordance with industry practice,
a typical compression ratio is 2:1 of data storage. Actual compression ratios
achieved depend on the redundancy of data files being written.
dB
A Decibel is a logarithmic unit of sound intensity; 10 times the logarithm of
the ratio of the sound intensity to some reference intensity.
DC
Direct Current
is the continuous flow of electricity through a conductor such
as a wire from high to low potential.
DCM
The Data Control Module provides the path and guides for all media
motion inside the tape drive and to write data to and read data from the media.
Device
According to the SCSI specification, multiple SCSI devices can be
connected to a single SCSI bus. Each SCSI device contains a SCSI ID number that
can be set in the range 0 to 15.
Device Driver
A low-level (usually kernel-mode) operating system component
that enables a PC to communicate with peripheral devices such as printers, CD-
ROMs, and tape drives. Each kind of device requires a different driver.
Differential
A term referring to the electrical characteristics of the signal used on
the SCSI bus interface. Differential signals minimize the effect of common mode
signal noise and allow the SCSI bus to operate reliably over greater distances at a
higher speed.
DLT
Digital Linear Tape.
DLTIce
The manufacturer’s firmware compliance management function of
DLTSage, which provides secure archival functionality to the tape drive and tape
cartridge.
DLTSage
The manufacturer’s suite of preventative maintenance diagnostic
software tools that enables users to more simply mange tape storage
environments.
DLZ
Digital Lempel-Ziv 1 Algorithm is named after Abraham Lempel and Jacob
Ziv. It is a data compression technique used in all tape drives.
E
EEC
European Economic Community.
EEPROM
Electronically Erasable Programmable Read-Only Memory. An
integrated circuit memory chip that can store programs and data in a non-volatile
state. These devices store firmware in tape drives, and can be erased and
reprogrammed with new data.
