Signed Binary Numbers

Signed Binary Numbers

• In practice, we use plus sign to represent positive number and minus sign to represent negative number.

• However, because of hardware limitations, in computers, both positive and negative numbers are represented with Sign only binary digits.

• The leftmost bit (sign bit) in the number represents sign of the number.

• The sign bit is 0 for positive numbers and it is 1 for negative numbers.

• Fig. 1.5.1 shows the sign magnitude format for 8-bit signed number.

• Here are some examples of sign-magnitude numbers.

Ex. 1.5.1 A binary machine handles negative numbers in the true magnitude form. How mil -4 be stored in a register with a sign bit and 4 bits representing magnitude ?

Sol.

Review Questions

1. What are l's complement and 2's complement numbers ?

2. State advantages of 2's complement number representation.

3. What are the different ways to represent a negative number ?

4. State the different ways for representing the signed binary numbers.