Seagate Technology 10002475-003, Руководство по описанию продукции

Страница: 79 / 84

Product Description Manual Page 71
Glossary
ATA Packet Interface—The interface providing for communications between the host computer and
the drive (standard QIC-157).
Azimuth—The angular deviation, in minutes of arc, of the mean flux transition line from the line
normal to the tape reference edge.
Backup—Copy of a file or collection of files on fixed disk, diskette, or tape. Ensures against data loss.
Beginning of Media (BOM)—Equal to the physical beginning of the tape.
Beginning of Tape (BOT)—Equal to the logical beginning of the tape.
Bezel—Front panel of a drive.
Bit—A single digit in the binary numbering system.
Bit Error Rate—The number of errors divided by the total number of bits written or read.
Block—A group of 512 consecutive data bytes plus additional control bytes recorded as a unit.
BOP—Beginning of Partition. The position at the beginning of the permissible recording region of a
partition.
BOT marker—The beginning of tape (BOT) marker is a set of two holes punched side by side in the
tape.
Byte—A group of 8 binary bits operated on as a unit.
Cancelmark—A "negative" Filemark or Setmark. When a Cancelmark follows as the first block in the
next frame after a Filemark or Setmark, the drive when reading the tape will logically ignore the
Cancelmark and the Filemark or Setmark it cancels.
Cartridge—An enclosure containing magnetic tape wound on two coplanar hubs.
Control field—A group of 8 bytes recorded before the data area in each block, continaing information
about clock address, track address, and block type.
Cyclic Redundancy Check (CRC)—A group of 2 bytes recorded at the end of each block of data for
the purpose of error detection.
Data block—A block containing user valid data in its data field
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.
A