Question

1. What are the four main functions that a computer is capable of?

2. What are bits and bytes?

3. Why are bits important in computers?

4. What number systems are used in computing?

5. What is meant by kilobytes, megabytes, gigabytes, and terabytes?

6. What are ASCII, extended ASCII, and Unicode? What are they used for, and how do they differ?

Answer 1

1.

Computer is an electronic device that recievs information and manipulates it based on sequesnce of instructions and gives quick result.

The basic functions of a computer system are as follows:
input
output
processing
storage

Input:
Input is nothing but transferring or rendering of information into the system. This may be through a keyboard or mouse some other program, cd etc.

Output:
The processor in computer executes the set of instructions that are given by user and then,Output is the function that allows a computer to display information for the user. This can be accomplished through the monitor, printer, speakers etc.

Processing:Here the computer actually does its work of manipulating and controlling data over the entire system.

Storage: computers are able to store data both temporarily but also long-term. We can transfer data to Storage locations through on hard-drives or external storage devices.

2) A bit is a short form of binary digit. And it is a smallest unit of data in computer.A bit can hold only one of two values: 0 or 1,which are binary values.In computers the istructions provided are manipulate with bits, but bit is a very small unit. Hence generally instructions are manipulated with bytes.

An eight bits digits long is nothing but a byte. It is a data unit in computer and it can store single ASCII character like 'R'.

Here is tha small logic that providing you that, one kilobyte is equal to 1024 bytes not one thousand bytes. Becuase we are measuring in binary units.

3) As per discussed bit is a small unit of data in computers. And it is useful for measuring the performance of computer like we have two types 32-bit and 64-bit. Processing capacity depends on this bit values. Bits are also used in telecommunication to measeure bits that are transmitted in given time.

4) Number systems: Number system is defined as the set values that repesesnts some quantity.The computer represents all kinds of data and information in binary numbers.

Computer architecture supports following number systems.

• Binary number system
• Octal number system
• Decimal number system
• Hexadecimal (hex) number system

a) Binary Number System

A Binary number system has only two digits that are 0 and 1. Each and every value represents with 0 and 1 in this number system. The base of binary number system is 2.

b) Octal number system

Octal number system contains digits from 0 to 7. Every value represents with 0,1,2,3,4,5,6 and 7 in this number system. The base of octal number system is 8.

c) Decimal number system

Decimal number system has ten digits from 0 to 9. Every value represents with 0,1,2,3,4,5,6, 7,8 and 9 in this number system. The base of decimal number system is 10.

d) Hexadecimal number system

A Hexadecimal number system contains sixteen alphanumeric values from 0 to 9 and A to F. Every number represents with 0,1,2,3,4,5,6, 7,8,9,A,B,C,D,E and F in this number system. The base of hexadecimal number system is 16. Here A is 10, B is 11, C is 12, D is 13, E is 14 and F is 15.

5) As per discussed bits and bytes are used to measure data. As volume of data getting heigher there are several measurements for each level of data.

Kilobyte is nothing but 1024 bytes,megabyte is nothing but 1024KB,gigabyte is 1024MB and terabyte is 1024GB.

6)A character set maps characters to some other code values. Unicode is a global standard for character encoding and is the most commonly used character set today.

ASCII code: Computers internally processes with binary system and they work with 0's and 1's only.

The computer converts characters into numbers, and then converts those numbers into binary. The system to encode letters and characters into numbers is called the ASCII code (American Standard Code for Information Interchange). It is a set of 128 characters.

ASCII is a 7-bit system. That means 7 bits, 128 numbers (0-127 in decimal notation) are available to code characters. ASCII was soon expanded to an 8-bit system that has 256 code points, 0-255 There are many variants of Extended ASCII characters to cover regional characters and symbols nothing but Extended ASCII.

In these 8-bit extensions, the lower 128 characters (0 to 127) are the same ASCII characters, while the upper 128 (128 t0 255) characters are changed and arranged for the appropriate language.This extended arrangement is notingbut unicode.