Correct me if I'm wrong. To subtract -4 (100), we need to complement all
three bits and add 1, which gives the same number. Unless there is another
procedure for subtracting a number..?

On 5/5/08, Robert Dick <dickrp@northwestern.edu> wrote:
>
> Kenny Tay:
> > Not really. Are you trying to say that I'm supposed to convert the
> number
> > to 4bit two's complement and then do the addition? I was thinking that
> the
> > Lab was phrased in a sense that it wanted you to deal with 3bit numbers
> and
> > then convert to 4bits only after the addition process.
>
> There is no conversion. The sum of two three-bit numbers is naturally
> four
> bits long. I don't understand why -4 poses any problem. What is the
> three-bit two's-complement encoding for -4?
>
> -Robert Dick-
>
>
Received on Mon May 5 07:50:04 2008