AI-3
LAW OF UNION A term ORed with 1 equals 1; a term ORed with 0 equals that term; A+1 = 1, A + 0 = 0.
LEAST SIGNIFICANT (LSD) The digit which has the least effect on the value of a number.
LOGIC The science of reasoning; the development of a reasonable or logical conclusion based on known
information.
LOGIC FAMILY A group of logic circuits based on specific types of circuit elements (DTL, TTL, CMOS, and
so forth).
LOGIC GATES Decision-making circuits in computers and other types of equipment.
LOGIC POLARITY The polarity of a voltage used to represent the logic 1 state.
LOGIC SYMBOL Standard symbol used to indicate a particular logic function.
MINUEND The number from which another number is subtracted.
MIXED NUMBER Represents one or more complete units and a portion of a single unit.
MODULUS The number of different values that a counter can contain or display.
MOST SIGNIFICANT DIGIT (MSD) The digit which if changed will have the greatest effect on the value of a
number.
NAND GATE An AND gate with an inverted output. The output is LOW when all inputs are HIGH, and HIGH
when any or all inputs are LOW.
NEGATIVE LOGIC The voltage representing logic state 1 is more negative that the voltage representing a logic
state 0.
NEGATOR See inverter.
NOR GATE An OR gate with an inverted output. The output is LOW when any or all inputs are HIGH, and
HIGH when all inputs are LOW.
NOT CIRCUIT See inverter.
NUMBER A symbol used to represent a unit or a quantity.
OCTAL SYSTEM The base 8 number system using 0 through 7 as the symbols.
OR GATE A logic circuit which produces a HIGH output when one or more inputs is/are HIGH.
PARALLEL DATA Each bit of data has a separate line and all bits are moved simultaneously.
PARALLEL REGISTER A register that receives, stores, and transfers data in a parallel mode.
POSITIONAL NOTATION A method where the value of the number is defined by the symbol and the symbol’s
position.
POSITIVE LOGIC The voltage representing logic state 1 is more positive than the voltage representing a logic
state 0.
POWER OF A NUMBER The number of times a base is multiplied by itself. The power of a base is indicated
by the exponent; that is, 103 = 10 10 10.
