"To obtain the code of -x from the code of x... flip all the bits of x and add 1 to the result."
when I try to do this to zero in my ALU, it doesn't work, I always end up back at zero
The extra one overflows. Am I doing something wrong? The book also says "Bit-wise negation of zero gives the 2’s complement code of -1.", so negating zero should end up with -1.