IBM TS22 Series, Руководство пользователя

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CE
Customer engineer; field engineer; service representative.
centimeter (cm)
One one-hundredth of a meter (0.01 m). Approximately 0.39 inch.
channel command
An instruction that directs a data channel, control unit, or device to complete an operation or set of operations.
char
Character.
CHK
Check.
cleaning cartridge
A tape cartridge that is used to clean the heads of a tape drive. Contrast with data cartridge.
command
A control signal that initiates an action or the start of a sequence of actions.
compact disc (CD)
A disc, usually 4.75 inches in diameter, from which data is read optically by using a laser.
compression
The process of eliminating gaps, empty fields, redundancies, and unnecessary data to shorten the length of records or blocks.
concurrent
Refers to diagnostic procedures that can be run on one control unit while the rest of the subsystem remains available for customer applications.
contingent connection
A connection between a channel path and a drive that is caused when a unit check occurs during an I/O operation.
controller
A device that provides the interface between a system and one or more tape drives.
CP
Circuit protector.
ctrl
Control.
CU
Control unit.
D
danger (notice)
A word to call attention to possible lethal harm to people. Contrast with attention and caution.
data
Any representations such as characters or analog quantities to which meaning is or might be assigned.
data buffer
The storage buffer in the control unit. This buffer is used to increase the data transfer rate between the control unit and the channel.
data cartridge
A tape cartridge that is dedicated to storing data. Contrast with cleaning cartridge.
data check
A synchronous or asynchronous indication of a condition that is caused by invalid data or incorrect positioning of data.
dc
Direct current.
degauss
To make a magnetic tape nonmagnetic by using electrical coils that carry currents that neutralize the magnetism of the tape.
degausser
A device that makes magnetic tape nonmagnetic.
degradation
A decrease in quality of output or throughput or an increase in machine error rate.
degraded
Decreased in quality of output or throughput or increased machine error rate.
deserialize
To change from serial-by-bit to parallel-by-byte.
detented
A part that is held in position with a catch or lever.
device
Any hardware component or peripheral device, such as a tape drive or tape library, that can receive and send data.
device driver
A file that contains the code that is needed to use an attached device.
DIAG
Diagnostic section of maintenance information manual.
differential
See High Voltage Differential (HVD).
direct access storage
A storage device in which the access time is independent of the location of the data.
DNS
Directory Name System. This system allows the library to recognize text-based addresses instead of numeric IP addresses.
download
To transfer programs or data from a computer to a connected device, typically a personal computer.
To transfer data from a computer to a connected device, such as a workstation or microcomputer.
DRAM
Dynamic random-access memory.
drive, magnetic tape
A mechanism for moving magnetic tape and controlling its movement.
IBM TS22xx Tape Drives 73