IBM 5170 Technical Reference page 403

Glossary
JL.
Prefix micro; 0.000 001.
JLs. Microsecond; 0.000 001 second.
A. Ampere.
ac. Alternating current.
accumulator. A register in which the result of an operation is
formed.
active high. Designates a signal that has to go high to produce an
effect. Synonymous with positive true.
~
active low. Designates a signal that has to go low to produce an
effect. Synonymous with negative true.
adapter. An auxiliary device or unit used to extend the operation
of another system.
address bus. One or more conductors used to carry the
binary-coded address from the processor throughout the rest of
the system.
algorithm. A finite set of well-defined rules for the solution of a
problem in a finite number of steps.
aU
points addressable
(APA).
A mode in which all points of a
displayable image can be controlled by the user.
alphameric. Synonym for alphanumeric.
alphanumeric (A/N). Pertaining to a character set that contains
letters, digits, and usually other characters, such as punctuation
marks. Synonymous with alphameric.
Glossary-l