Q#8 (1 mark):

Represent decimal 3984 in the 2421 code. Show that complementing all bits of the coded number produces the 9's complement of 3984 in the 2421 code.

Note: The decimal number 9 is represented in 2421 code as 1111

Solution

Q#9 (3 marks):

1. Obtain the 9's complement of the following eight-digit decimal numbers: A=90009951; and B=00980100
2. Obtain the 10's complement of the following eight-digit decimal numbers: A=90009951; and B=00980100
3. Suppose that we use the 10s complement of X to represent X. Show that A-B can be performed as A+ (-B); i.e., by taking the 10s complement of B and adding it to A (and ignoring the carry out of the 8-digit decimal values).

Solution:

a.

b.

c.

Q#10 (2 marks):

List the 10 BCD digits with an even parity in the leftmost position (total of five bits per digit). Repeat with an odd-parity bit.

Solution

Decimal	BCD with even parity	BCD with odd parity
0
1
2
3
4
5
6
7
8
9