Seagate STD124000N Product Manual page 109

Glossary
Product Manual
frame. Two adjacent tracks, one A channel (positive azimuth) and one B channel
(negative azimuth).
full-height. Usually refers to a tape drive that fits into a vertical space of 3.5 inches.
group. A fixed-capacity set of frames written to or read from the tape. For the DDS
and DDS-DC formats, 22 frames comprise a group.
half-height. Refers to the size of a tape drive that occupies a vertical space of
about 1.5 inches.
head clog. Particles from the tape or from outside the drive adhere to the head gap
on a read or write head and obstruct the reading or writing of data.
helical scan recording. A method of magnetically recording a tape in which the
tape wraps around a rotating cylinder with 2 or 4 read/write heads writing at different
azimuth angles across the width of the tape in a helix-shaped track.
housekeeping frame. A frame that contains no user data and which is identified as
such by the values in the data fields therein.
interleaving. The process of shuffling the order of data bytes before writing them to
tape so the consecutive bytes are recorded as far away from each other as
possible.
logical beginning of tape. The point along the length of the tape where a recording
of data for interchange begins.
magazine. The specially designed, multiple cartridge container that mounts in the
magazine holder of the autoloader.
magnetic tape. A tape that accepts and retains magnetic signals intended for input,
output and storage of data for information processing.
N -group writing. Sometimes called multiple group writing. This technique repeats
each group of data so that there are N consecutive copies of each group on the
tape.
noise. A disturbance of the signal caused by the read channel, write channel,
head/tape interaction, or conducted or radiated sources.
partition boundary. The point along the length of a magnetic tape at which partition
1 ends and partition 0 begins.
physical beginning of tape (PBOT). The point where the leader tape is joined to
the magnetic tape.
physical end of tape (PEOT). The point where the trailer tape is joined to the
magnetic tape.
processing. The use of an algorithm to transform host data into codewords.
processed data. A sequence of codewords that results from the application of
processing to data.
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