At 10:06  7/03/00 +0200, you wrote:
>Hi
>
>I'm looking for the way to calculate what the Two's
>Complement of a value will be. Can anyone help me?
>For instance:
>
>8-bit value:
>01101110
>10010001 (Inverted)
>
>But this is not two's complement yet!? What Next?
>
>Can somebody maybe also solve this one:
>16-Bit value:
>01011100 11110110
>10100011 00001001 (Inverted)
>
>Thanks!!!
>
Somebody has already pointed out that you need to invert the number then add
1. Here's a short cut you may find useful.
Starting at the least significant bit, copy any trailing 0's and the first 1
you encounter. Now invert everything to the left.

eg1. 101000011 00001001    There are no trailing 0's so copy the lsb (1) and
invert all to the left
     010111100 11110111

eg2. 11001111 00010000  number
     00110000 11110000  2's comp

cheers.
Bob Jenner
Trading as RAJE Consulting
3 Cahill Cr Nakara NT 0810
Tel 08 89 455 796
Fax 08 89 275147
http://www.coolspot.com.au