Number Representation

How do we represent signed (positive & negative) numbers?

Option 2: One's Complement

• Flip every bit to represent the number's negative value
  (Note: this works both ways!)
• Left-most bit still represents the sign
• Examples:

          00000001  = +1
          11111110  = -1   (one's complement)
  
          00000101  = +5
          11111010  = -5   (one's complement)
  
          01111111  = +127
          10000000  = -127   (one's complement)

• Problem 1:

          00000000  = +0
          11111111  = -0   (one's complement)

• Problem 2:

           00000101     5
           11111110  + -1
           --------  -----
          100000011  overflow  ???