IBM B-Series, Maintenance Information

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interblock gap (IBG). An area on a data medium to
indicate the end of a block or physical record.
interface. A shared boundary. An interface might be a
hardware component to link two devices or it might be a
portion of storage or registers accessed by two or more
computer programs.
interposer. The part used to convert a 68-pin
connector to a 50-pin D-shell connector.
intervention required. Manual action is needed.
INTRO. Introduction.
I/O. Input/output.
IOP. Input/output processor.
IPL. Initial program load.
IPS. Independent Position Sensor.
IOCDS. I/O configuration data set.
IOCP. I/O Configuration Program.
ITST. Idle-time self-test.
K
km. kilometer.
L
LAN. Local area network. A computer network within a
limited area.
LED. Light-emitting diode.
loadable. Having the ability to be loaded.
LUN. Logical unit.
LZ-1. Lempel-Ziv electronic data compactor.
M
Magazine. A container of 10 cartridges that is loaded
into the Library.
magnetic tape. A tape with a magnetical surface layer
on which data can be stored by magnetic recording.
MAP. Maintenance analysis procedure.
mask. A pattern of characters that controls the
retention or elimination of portions of another pattern of
characters. To use a pattern of characters to control the
retention or elimination of portions of another pattern of
characters.
master file. A file used as an authority in a given job
and that is relatively permanent, even though its
contents may change. Synonymous with main file.
media capacity. The amount of data that can be
contained on a storage medium, expressed in bytes of
data.
micro. One millionth of.
microcode. (1) One or more micro instructions. (2) A
code, representing the instructions of an instruction set,
implemented in a part of storage that is not
program-addressable. (3) To design, write, and test
one or more micro instructions. (4) See also
microprogram.
microdiagnostic routine. A program that runs under
the control of a supervisor, usually to identify field
replaceable units.
microdiagnostic utility. A program that is run by the
customer engineer to test the machine.
microinstruction. A basic or elementary machine
instruction.
microprogram. A group of microinstructions that when
executed performs a preplanned function.
The term microprogram represents a dynamic
arrangement or selection of one or more groups of
microinstructions for execution to perform a particular
function. The term microcode represents
microinstructions used in a product as an alternative to
hard-wired circuitry to implement certain functions of a
processor or other system component.
Migration. Going from one tape subsystem to a
different tape subsystem.
MIM. Media information message.
mm. Millimeter.
modifier. That which changes the meaning.
mount a device. To assign an I/O device with a
request to the operator.
MP. Microprocessor.
ms. Millisecond.
MSG. Message.
multipath. Pertaining to using more than one path.
Gloss-4
IBM 3570 MI