CS/COE 447 Quiz 4  February 12, 2007
====================================
Q1:  Represent -10 (decimal) as 8-bit sign magnitude, 1's complement, and 2's
complement numbers:

  +10 decimal = 00001010

  Sign Magnitude:  10001010



  1's complement: 00001010 +10
                  11110101 -10, 1's complement




  2's complement: 11110101
                  +      1
                 -----------
                  11110110

    For a check, take the 2's complement of the answer:

    flip:  00001001
           +      1
           --------
           00001010  -- this is +10, so our answer above is correct.

Q2:  Assuming 8-bit numbers in 2's complement, perform the following
calculation.  Clearly label your answer and show your work.

   -10 + 3

        11110110
        00000011
       ----------
        11111001

Take 2's complement to check:

    00000110 flip
    +      1
   ----------
    00000111  = 7, so above answer is correct.
       


Q3:  Assuming 8-bit numbers in 2's complement, perform the following
calculation.  Clearly label your answer and show your work.

   -10 + -3

00000011 = 3
11111100 flip
+      1
--------
11111101 = -3

        11110110
       +11111101
      -----------
        11110011

Take 2's complement to check:

        11110011
        00001100  flip
        +      1
       ---------
        00001101  = 13, so above answer is correct.