IBM 6150 Hardware Maintenance Manual page 631

terminal or a processing unit, that interprets and
executes instructions.
program. A file containing a set of instructions
conforming to a particular programming
language syntax.
radio frequency (RF). An ac frequency that is
higher than the highest audio frequency. So
called because of the application to radio
communication.
RAM. Random access memory. Read/write
memory.
random access memory (RAM). Read/write
memory.
raster. A predetermined pattern of lines that
provides uniform coverage of a display space.
read. To acquire or interpret data from a
storage device, from a data medium, or from
another source.
read-only memory (ROM). A storage device
whose contents cannot be modified. The
memory is retained when power is removed.
read/write memory. A storage device whose
contents can be modified. Also called RAM.
resident. Permanently located in memory, such
as read-only memory.
ROM. Read-only memory.
RS232C. A standard by the EIA for
communication between computers and external
equipment.
X-4 Service Manual
setup. ( 1 ) In a computer that consists of an
assembly of individual computing units, the
arrangement of interconnections between the
units, and the adjustments needed for the
computer to operate. (2) The preparation of a
computing system to perform a job or job step.
Setup is usually performed by an operator and
often involves performing routine functions,
such as mounting tape reels. (3) The
preparation of the system for normal operation.
software. (1) Computer programs, procedures,
and rules concerned with the operation of a data
processing system. (2) Contrast with
hardware.
source number. The two leftmost digits of a
service request number. Identifies the entity
that sensed the error.
SRA
number. Service repair action number.
SRN.
Service request number.
storage. (1) The location of saved
information. (2) In contrast to memory, the
saving of information on physical devices such
as disk or tape. See memory. (3) The retention
of data in a storage device. (4) The placement
of data into a storage device.
synchronous transmission. (1) Data
transmission which the time of occurrence of
each signal representing a bit is related to a
fixed time frame. (2) Data transmission which
the sending and receiving devices are operating
continuously at substantially the same
frequency and are maintained, through
correction, in a desired phase relationship.