IBM 5150 Technical Reference page 289

programming system. One or more programming languages and
the necessary software for using these languages with particular
automatic data-processing equipment.
PROM. Programmable read-only memory.
propagation delay. (1) The time necessary for a signal to travel
from one point on a circuit to another.
(2)
The time delay
between a signal change at an input and the corresponding change
at an output.
protocol.
(1)
A specification for the format and relative timing of
information exchanged between communicating parties. (2) The
set of rules governing the operation of functional units of a
communication system that must be followed if communication is
to be achieved.
pulse. A variation in the value of a quantity, short in relation to
the time schedule of interest, the final value being the same as the
initial value.
radio frequency (RF). An ac frequency that is higher than the
highest audio frequency. So called because of the application to
radio communication.
radix.
(1)
In a radix numeration system, the positive integer by
which the weight of the digit place is multiplied to obtain the
weight of the digit place with the next higher weight; for example,
in the decimal numeration system the radix of each digit place is
10. (2) Another term for base.
radix numeration system. A positional representation system in
which the ratio of the weight of anyone digit place to the weight
of the digit place with the next lower weight is a positive integer
(the radix). The permissible values of the character in any digit
place range from
a
to one less than the radix.
RAM. Random access memory. Read/write memory.
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