Seagate STD124000N Product Manual page 108

Glossary
cutout. The cut-away or step-down portion of the autoloader case that provides
access to switches, jumpers and connectors.
data area. The third section of a tape on a DAT cartridge, which is written as a
series of groups beginning with the special vendor group.
data compression. The process of removing redundant data from a data stream
before recording the data to tape. Compressed data requires less storage space
than uncompressed data.
data density. The number of single-byte characters stored per unit length of track.
Usually expressed as bits-per-inch (bpi).
data format ID. An identifier that specifies which data format is used on the tape.
decompression. The process of restoring compressed data to its original state.
dictionary. The collection of representations (numeric values) of unique character
strings encountered when compressing data.
direct-access operation. Operation of the autoloader in which SCSI commands
issued by the host computer select the cartridge, retrieve the cartridge from the
magazine and load/unload the cartridge from the drive.
disc drive. A peripheral storage device that rotates the disc, writes data onto it and
reads data from it as instructed by a program.
early warning point (EWP). A point along the length of the tape where a warning is
given of the approach, in the forward direction of tape motion, of the partition
boundary or of the physical end of tape.
end-of-data (EOD). Indicates the point where the host stopped writing data to the
tape.
end-of-media (EOM). Equal to the physical end of tape where the trailer tape is
joined to the magnetic tape.
end-of-tape (EOT). Equal to the logical end of the tape.
entity. A recorded object that consists of an entity header followed by one or more
compressed records.
error-correction code (ECC). Information written on tape during the recording
operation that can later be used to reconstruct errors during the data reading
operation.
file. A logical unit of information.
fixed disc. A nonremovable hard disc. All data must be transferred to and from the
disc through the computer.
fragment. A collection of bytes that are treated as a unit for recording, readback
and error correction purposes.
Page 96 DAT Drives