Question

Convert decimal 3,712 and 4,132 to both BCD and ASCII codes. For ASCII, an even parity bit is to be apppended at the left.

Answer 1

(1)

(i) 3712₁₀

3₁₀ = 0011BCD

7₁₀ = 0111_BCD

1₁₀ = 0001_BCD

2₁₀ = 0010_BCD

Therefore, 3712 in BCD = 0011 0111 0001 0010

(ii)

ASCII Value	Hex Decimal	Decimal	Binary	ASCII CODE (even parity)
3	33	3x161+3x160 = 51	0110011	0 0110011
7	37	3x161+7x160 = 55	0110111	1 0110111
1	31	3x161+1x160 = 49	0110001	1 0110001
2	32	3x161+2x160 = 50	0110010	1 0110010

Therefore, ASCII Code: 00110011  10110111  10110001  10110010

Note: Bold bits are parity bits.

Method 2: (Shortcut)

To convert to ASCII

Step 1: Add 48 to given character

3 + 48 = 51

7 + 48 = 55

1 + 48 = 49

2 + 48 = 50

step 2: Now convert obtained decimal numbers to binary

51 = 0110011₂

55 = 0110111₂

49 = 0110001₂

50 = 0110010₂

Step 3:

Even parity means total number 1's should be even. If a number contains odd 1's append 1 to it's left to make it even.

If it contains odd 1's append 0 to it's left.

ASCII code: 00110011  10110111  10110001  10110010

2)

(i) 4132₁₀

4₁₀ = 0100

1₁₀ = 0001

3₁₀ = 0011

2₁₀ = 0010

BCD :  0100 0001 0011 0010

(ii)

ASCII Value	Hex Decimal	Decimal	Binary	ASCII CODE (even parity)
4	34	3x161+4x160 = 52	0110100	1 0110100
1	31	3x161+1x160 = 49	0110001	1 0110001
3	33	3x161+3x160 = 51	0110011	0 0110011
2	32	3x161+2x160 = 50	0110010	1 0110010

ASCII Code of 4132 is : 10110100  10110001  00110011  10110010