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
onescomplement, 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)