1.3.4 SIGNED MAGNITUDE CONVENTION

      1.      To represent negative numbers, WE NEED A NOTATION FOR NEGATIVE VALUES.

2.      The convention is to make the sign bit 0 for positive and 1 for negative.

3.      The user determines whether the number is signed or unsigned:

a.       If the binary number is signed, then the leftmost bit represents the sign and the rest of the bits represent the number.

b.      If the binary number is assumed to be unsigned, then the leftmost bit is the most significant bit of the number.

0101

ü  5 (unsigned number)

ü  +5 (signed number) (leftmost bit is 0)

1101

ü  13 (unsigned number)

ü  -5 (signed number) (leftmost bit is 1)

NOTE: There is no confusion in identifying the bits if the type of representation for the number is known in advance.