IBM 5251 Series Maintenance Information Manual page 12

field attribute: The control characters that describe a
displayed field. For example, a display field can be
intensified, reversed, underscored, or made to blink.
flyplate: The bottom of a key module. See reference
135.
FRU: Field-replaceable unit.
hex: Hexadecimal.
HH:MM:SS: Hours, minutes, and seconds.
10:
Identification.
implode: To break inward suddenly.
Ins key: The key on the keyboard that is used to select
the insert mode.
IPL: Initial program load.
KBD: Keyboard.
key stem: The connecting part between the key top and
the key module. See reference 135.
Keylock feature: A feature with a lock and key that
restricts the use of the display station.
keystroke: The action of pressing a key on the
keyboard.
LED: Light-emitting diode.
linearity: The size of displayed characters of equal
width.
line turnaround: The time between the reception of the
last bit of a frame by a work station and the start of
transmission by that same work station.
LP: Light pen.
LRC: Longitudinal redundancy check.
main planar: The basic printed circuit electronic board
used in the display station.
make/break key: A key that generates a scan code
when the key is pressed and when it is released.
mandatory: Something that must be done or must be
present.
menu: A list of options that can be selected.
microfarad: One millionth part of a farad.
microinstruction: A basic or elementary machine
instruction.
microprocessing: Operations performed by the MPU.
xii
microprocessing unit (MPU): A processing unit that is
microprogram controlled and performs internal machine
operations. The MPU receives data, controls the display
of data, and controls the flow of information to and
from the controller.
microprogram: A program that uses microinstructions
to carry out system operations.
mini-MAP: A maintenance analysis procedure that is
located in the maintenance information manual. A
mini-MAP continues the failure analysis after one of the
other MAPs has located the area that is failing.
MPU: Microprocessing unit.
MSR: Magnetic Stripe Reader feature.
mm: Millimeter.
ms: Millisecond.
msg: Message.
MSIPL: Main storage initial program load.
multiframe response: More than one frame of data is
being sent.
N/C: Pertains to a switch setting; normally closed.
N/O: Pertains to a switch setting; normally open.
null: A hex character composed of all zeros; this
character occupies a position in the buffer and is
displayed as a blank.
online test: A series of tests that can be requested
from the system after power on and before sign-on.
See reference 206.