The single 48-bit accumulator was fundamentally subtractive, addition being carried out by subtracting the ones' complement of the number to be added. This may appear rather strange, but the subtractive adder reduces the chance of getting negative zero in normal operations.
the single 48-bit accumulator was fundamentally subtractive addition being carried out by subtracting the ones' complement of the number to be added this may appear rather strange but the subtractive adder reduces the chance of getting negative zero in normal operations