IBM XT 5160 Technical Reference page 397

parallel. (1)
Pertaining to the concurrent or simultaneous
operation of two or more devices, or to the concurrent
performance of two or more activities. (2) Pertaining to the
concurrent or simultaneous occurrence of two or more related
activities in multiple devices or channels. (3) Pertaining to the
simultaneity of two or more processes. (4) Pertaining to the
simultaneous processing of the individual parts of a whole, such as
the bits of a character and the characters of a word, using
separate facilities for the various parts. (5) Contrast with serial.
parameter.
(1) A variable that is given a constant value for a
specified application and that may denote the application. (2) A
name in a procedure that is used to refer to an argument passed to
that procedure.
parity bit. A
binary digit appended to a grou'p of binary digits to
make the sum of all the digits either always odd (odd parity) or
always even (even parity).
parity check. ( 1) A
redundancy check that uses a parity bit.
(2) Synonymous with odd-even check.
PEL.
Picture element.
personal computer. A
small home or business computer that has a
processor and keyboard and that can be connected to a television
or some other monitor. An optional printer is usually available.
phototransistor. A
transistor whose switching action is controlled
by light shining on it.
picture element (PEL).
The smallest displayable unit on a
display.
polling. (1)
Interrogation of devices for purposes such as to
avoid contention, to determine operational status, or to determine
readiness to send or receive data. (2) The process whereby
stations are invited, one at a time, to transmit.
port.
An access point for data entry or exit.
positive true.
Synonym for active high.
Glossary-26