CS Chap #1 (Sub-topic 1.1: Data Representation)

Question 1

Binary

Answer 1

number system is base 2, using only bits 0 and 1.

Question 2

One’s Complement and Two’s Complement

Answer 2

1. Invert all number. ( 1 becomes 0, 0 becomes 1).
2. After One’s Complement add one to the solution.

Question 3

Hexadecimal

Answer 3

number system is base 16, using only digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.( A=10, B=11, C=12, D=13, E=14 and F=15)

Question 4

Binary Coded Decimal (BCD)

Answer 4

number system that uses 4 bits to represent each denary digit

Question 5

ASCII code

Answer 5

Coding system for all the characters on a keyboard and control codes.

Question 6

Unicode

Answer 6

Coding system which represents all the languages of the world (first 128 characters are the same as ASCII code).

Question 7

Kibibyte, Mebibyte, Gibibyte, Tebibyte, Pebibyte

Answer 7

2^10, 2^20, 2^30, 2^40, 2^50

Question 8

Kilobyte (KB), Megabyte (MB), Gigabyte (GB), Terabyte (TB), Petabyte (PB).

Answer 8

10^3, 10^6, 10^9, 10^12, 10^15

Question 9

How to convert form Hexadecimal to Binary?

Answer 9

Use four bits in decimal to represent one hexadecimal value. (Vice versa for Binary to Hexadecimal)

Question 10

Uses of Hexadecimal

Answer 10

Memory Dump, Error Messages, HTML Colour, IP Address

Question 11

Uses of BCD

Answer 11

When denary numbers need to be electronically coded and/or displayed.

e.g.
- to operate displays on an electronic calculator
- Date and time stored in BIOS of PCs
- Financial applications
- Identification of latitude and longitude (e.g. cell towers)
- Barcodes

Question 12

Difference between ASCII and Unicode

Answer 12

ASCII- 7-bit system (128 character),
Unicode- extended character set for ASCII that has 1,000s of characters (first 128 of both are the same)

Question 13

Advantages of Unicode

Answer 13

• Much larger number of characters or group of characters
• Contains some non western european characters