RE: FN-FORUM: Twos Complement Binary

date posted 13th January 2007 19:51

Gary Short wrote:
>> I appreciate that this probably isnt the best place to ask this
>> question but I have a computing exam on monday and am struggling
>> understanding how twos complement binary works!!!
>>
>> Does anyone know of any simple tutorials or can anyone give me a
>> brief description of how the system works?

FWIW 1's complement didn't add the extra one so you got two values for zero:
0 and -0. I used to program a 1's complement machine in Assembler and it
was a serious pain having to test for both values of zero. OTOH, we often
used -0 as a kind of null indicator.

Andy Henderson