This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
The binary of 4 "00000100" If you do a complement if becomes "11111011" which is actually -5. Just remember this when you do a complement on a positive number the resulting negative number will be one greater than the original positive number with a negative sign.
~4 = -(4+1)
When we are doing a complement we are actually doing a two's complement.