< data > A system used in some computers to represent negative numbers in binary . Each bit of the number is inverted (zeros are replaced with ones and vice versa), as for ones complement , but then one (000...0001) is added (ignoring overflow). This avoids the two representations for zero found in ones complement by using all ones to represent -1.
... 000...00011 = +3 000...00010 = +2 000...00001 = +1 000...00000 = 0 111...11111 = -1 111...11110 = -2 111...11101 = -3 ...
This representation simplifies the logic required for addition and subtraction, at the expense of a little extra complexity for negation.
(1994-10-31)