Glossary g-51
Glossary
plished by sharing the resources of a real data processing system. (2)
A functional simulation of a computer system and its associated
devices, multiples of which can be controlled concurrently by one
operating system (D, T).
virtual storage VS. (1) Storage space that may be regarded as addressable main stor-
age by the user of a computer system in which virtual addresses are
mapped to real addresses. The size of virtual storage is limited by the
addressing scheme of the computer system and by the amount of
auxiliary storage available, not by the number of main storage loca-
tions. (2) Addressable space that is apparent to the user as processor
storage space, from which the instructions and the data are mapped
to the processor storage locations (A, D, I).
volt A measure of the difference in electrical potential between two points
in a conductor, equal to one ohm resistance carrying a constant cur-
rent of one ampere, with a power dissipation of one watt (D). See
volts alternating current; volts direct current.
volts alternating
current VAC. A term for classifying the system in which volts exist. VAC
means that the volts exist in a circuit where the electricity can travel
in either direction. Contrast with volts direct current. See volt.
volts direct current VDC. A term for classifying the system in which volts exist. VDC
means that the electricity has a specific path it must follow. Contrast
with volts alternating current. See volt.
W
warning message A message that indicates a possible error has been detected. See also
error message.
watt A unit of power in the International System equal to one joule (New-
ton-meter) per second (D).
window The main window for the EFC Manager application or Product Man-
ager applications. Each application has a unique window that is
divided into separate panels for the title, navigation control, alerts,
and the main or Product View. The user performs all management and