1. Data Storage

2. SIGN AND MAGNITUDE Storing and representing numbers

3. Give the sign and magnitude of -30

4. Give the sign and magnitude of the following integers + 60 and -60 +90 and -90 +29 and -29

5. TWO’S COMPLEMENT REPRESENTATION

6. Represent -50 in two’s complement

7. Represent -38 in two’s complement

8. Perform the calculation 75 – 30, using two’s complement method.

9. Perform the calculation 90 – 30, using two’s complement method.

10. Perform the calculation 52– 27, using two’s complement method.

11. BINARY CODED DECIMAL(BCD) Storing and representing digits and characters

12. Binary coded decimal (BCD) is a system of writing numerals that assigns a four-digit binary code to each digit 0 through 9 in a decimal (base-10) numeral. Computer use the number system you have been studying in order to carry out calculations. Once a calculation is completed, the result has to be displayed in the decimal format on the screen, for example on electronic scoreboard, calculators, microwave ovens and digital clock.

13. BCD Representations 0000 – 0 0001 – 1 0010 – 2 0011 – 3 0100 – 4 0101 – 5 0110 – 6 0111 – 7 1000 – 8 1001 – 9 1101 – (-) negative sign 1011 – (-)

14. Represent the digits 4901 in BCD form

15. Give the BCD representations of the following numbers: 91 430 256 -81 297

16. Covert BCD representation 010101111001 to decimal

17. Covert BCD representation 100000000101 to decimal

18. Covert the following BCD values into decimal 00101001 00110000 01110101 10010111 10000000

19. Exam extract

20. ASCII ASCII (American Standard Code for Information Interchange) is a character-encoding scheme. Originally based on the English alphabet, it encodes 128 specified characters into 7-bit binary integers.

22. Example In a computer system using the seven bit ASCII representation, the letter J would be represented by 1001010 or 74, Give the ASCII representation of letters E and P.

24. Exercise 1 The ASCII representation of letter P has a decimal value of 80. What is the ASCII representation of letter S?

25. Exercise 2

26. Home Work