IBM Netfinity 3000, User Handbook Manual

Page: 339 / 370

doped silicon, and that when
energized produce a flow of positive
charge carriers (holes).
POST . Power-on self-test.
power-on self-test (POST) . A
series of diagnostic tests that are run
automatically by a device when the
power is turned on.
processing . The performance of
logical operations and calculations
on data, including temporary
retention of data in microprocessor
storage while the data is being
operated on.
processing unit . (1) A functional
unit that consists of one or more
processors and their internal
storages. (I) (A)
(2) See
processor.
processor . A functional unit that
interprets and executes instructions.
A processor consists of at least an
instruction control unit and an
arithmetic and logic unit. (T) See
microprocessor and central
processing unit.
program . (1) A sequence of
instructions that a computer can
interpret and execute. (2) To
design, write, modify, and test
computer programs. (I) (A)
programmable read-only memory
(PROM)
. A storage device that,
after being written to once, becomes
read-only memory. (T) (A)
prompt . A visual or audible
message sent by a program to
request the user's response. (T)
PUN . Physical unit number.
R
RAID . Redundant array of
independent disks.
RAM . Random access memory.
random access memory (RAM) .
(1) A storage device in which data
can be written and read. (2) A
storage device into which data is
written and from which data is read
in a nonsequential manner.
RAS . Reliability, availability, and
serviceability.
read . To acquire or interpret data
from a storage device, from a data
medium, or from another source.
read-only memory (ROM) .
Memory in which stored data
cannot be modified by the user
except under special conditions. See
also EEPROM, EPROM, and PROM.
record . (1) A set of data treated as
a unit. (2) A set of one or more
related data items grouped for
processing.
refresh . (1) To recharge a memory
location in volatile memory with an
electric current so that it retains a
state or binary value. (2) In
computer graphics, the process of
repeatedly producing a display
Glossary
305