Page 29 - The Illustrated Dictionary of Electronics

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14 adapter • address generation

addend In a calculation, any number to be added
to another. Compare AUGEND.
addend register In a digital computer, the register
that stores the addend.
adder 1. In a digital computer, the device or circuit
that performs binary addition. A HALF ADDER is
a two-input circuit that can produce a sum out-
put and a carry output, but it cannot accommo-
date a carry signal from another adder. A FULL
ADDER can accommodate a carry input, as well
as two binary signals to be added. Also see ANA-
LOG ADDER. 2. A circuit in a color TV receiver
auxiliary system or unit used to extend the oper- that amplifies the receiver primary matrix signal.
ation of another system (e.g., a citizens-band additive 1. The character or characters added to a
adapter for a broadcast receiver). code to encipher it. 2. In a calculation, an item
adaptive communication A method of communi- that is to be added. 3. An ingredient, usually in a
cation that adjusts itself according to the particu- small quantity, added to another material to im-
lar requirements of a given time. prove the latter in quality or performance.
adaptive suspension vehicle Abbreviation, ASV. additive color A color formed by combining the
A specialized robot that moves on mechanical rays from two or three primary-colored lights
legs, rather than on wheels. It generally has six onto a single neutral surface. For example, by
legs and resembles an insect. It is designed to projecting a red and a green beam onto a neutral
move over extremely irregular or rocky terrain, screen, a yellow additive color results.
and to carry a human passenger. additive primaries Primary colors that form other
adaptivity The ability of a system to respond to its colors in a mixing of light (see ADDITIVE COLOR),
environment by changing its performance char- but are not themselves formed by mixing other
acteristics. additive primaries. For example, red, green, and
adc Abbreviation of ANALOG-TO-DIGITAL CON- blue are the additive primaries used in color tele-
VERTER. vision. Through appropriate mixing, these colors
Adcock antenna A directional antenna system can be used to generate an unlimited variety of
consisting of two vertical antennas, spaced in other colors. Compare SUBTRACTIVE PRI-
such a way that the whole array behaves like a MARIES, which form the color spectrum by mix-
loop antenna. Its members are connected and po- ing pigments rather than lights. In additive
sitioned so that it discriminates against horizon- systems, each superimposed primary color in-
tally polarized waves, and delivers output that is creases the total light output from the reflecting
proportional to the vector difference of signal volt- (viewing) surface; in subtractive systems, each su-
ages induced in the two vertical arms.
perimposed primary decreases the total reflectiv-
ity. Thus, equal combination of additive primaries
produces gray or white, and equal combination of
subtractive primaries produces gray or black.
addition record An extra data store created in a
computer during processing.
address 1. In computer operations, a usually nu-
merical expression designating the location of
material within the memory or the destination of
such material. 2. The accurately stated location
of information within a computer; a data point
within a grid, matrix, or table; a station within a
network. 3. In computer operations, to select the
location of stored information.
address comparator A device that ensures that
Adcock direction finder A radio direction-finding the address being read is correct.
system based on the directivity of the ADCOCK address computation In digital computer opera-
ANTENNA. tions, the technique of producing or modifying
Adcock radio range A radio range system with only the address part of an instruction.
four ADCOCK ANTENNAS situated at the corners address field In a computer, the part of the in-
of a square, and a fifth antenna at the center of struction that gives the address of a bit of data (or
the square. a word) in the memory.
add-and-subtract relay A stepping relay that can address generation The programmed generation
be switched either uprange (add) or downrange of numbers or symbols used to retrieve records
(subtract). from a randomly stored direct-access file.