1.Data information

1. Data Information

Content

IntroductionTransforming data into informationData representation in ComputerSummary

Introduction

The computer accepts data as an input, stores it process it as the user requires and produces information or processed data as an output in desired format.

Computer is one of the major component of an Information Technology and is gaining increasing popularity.

Basic Computer operations: It accepts data or instruction by way of input. It stores data. It can process data as required by the user. It gives result in form of output . It controls all operations inside a computer.

Transforming data into information

The process of producing results from the data for getting useful information can be termed as

Transforming Data Into Information.

What is Data?Data can be defined as a representation of facts, concepts or instruction in a formalized manner which should be suitable for communication , interpretation or processing by human or electronic machine.

Data is represented with the help of characters like alphabets (A-Z, a-z), digits (0-9) or special characters(+,-,/,*,<,>,= etc).

What is Information? Information is organized or classified data so that it

has some meaningful values to the receiver. Information is the processed data on which decisions and actions are based.

For the decision to be meaningful, the processed data must qualify for the following characteristics

Timely - Information should be available when required. Accuracy - Information should be accurate. Completeness - Information should be complete.

DATA PROCESSING: Data processing is the re-structuring or re-ordering

of data by people or machine to increase their usefulness & add values for particular purpose.

Data processing consists of basic steps input, processing and output. These three steps constitute the data processing cycle.

Data Processing Cycle

Input – In this step the input data are prepared in some convenient form for processing. The form will depend on the processing machine. For example, when electronic computers are used, the input data could be recorded on any one of several types of input medium, such as magnetic disks, tapes and so on.

Processing – In this step input data are changed to produce data in a more useful form. For

example, pay-checks may be calculated from the time cards, or a summary of sales for the month may be calculated from the sales orders.

Output –Here the result of the proceeding processing step are collected. The particular form of the output data depends on the use of the data. For example, output data may be pay-checks for employees.

Storage –Finally the storage unit is used to store data or information permanently.

Basic Computer Operations


Functional Units

The computer system is divided into three separate units for its operation. They are:

Arithmetic Logical unit Control Unit Central Processing Unit


Functional Units Arithmetic Logical Unit {ALU}:

After you enter data through input device it is stored in the primary storage unit.

The actual processing of the data and instruction are performed by Arithmetic Logical Unit.

Operation performed by the ALU are: Addition Subtraction Multiplication Division Logic Comparison

Arithmetic Logical Unit (ALU)


Functional Units Control Unit (CU):

Acts like the supervisor seeing that things are done in proper fashion.

Determines the sequence in which computer programs and instructions are executed.

Control Unit


Functional Units Central Processing Unit (CPU):

The ALU and the CU of a computer system are jointly known as the central processing unit.

CPU can be called Brain of any computer system. It takes all major decisions, makes all sorts of

calculations and directs different parts of the computer functions by activating and controlling the operation.

Data representation in Computer

Instruction data representation considers how a computer uses numbers to represent data inside the computer.

Three types of data are considered at this stage: Number including positive , negative and fractions Text Graphics

What is Computer Number System?

COMPUTER -NUMBER SYSTEM

When we type some letters or words, the computer translates them in numbers as computers can understand only numbers.

A computer can understand positional number system where there are only a few symbols called digits and these symbols represent different values depending on the position they occupy in the number.

A value of each digit in a number can be determined using The digit The position of the digit in the number The base of the number system (where base is defined as the

total number of digits available in the number system).

Decimal Number System The number system that we use in our day-to-day life is the

decimal number system. Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represent units, tens, hundreds, thousands and so on.

Each position represents a specific power of the base (10). For example 1234 can be written as:

(1x1000)+ (2x100)+ (3x10)+ (4xl)(1x103)+ (2x102)+ (3x101)+ (4xl00)1000 + 200 + 30 + 11234

As a computer programmer or an IT professional, you should understand the following number systems which are frequently used in computers.S.N. Number System & Description

1 Binary Number SystemBase 2. Digits used: 0, 1

2 Octal Number SystemBase 8. Digits used: 0 to 7

3 Hexa Decimal Number SystemBase 16. Digits used: 0 to 9, Letters used: A- F

Binary Number System Uses two digits, 0 and 1. Also called base 2 number system Each position in a binary number represents a 0

power of the base (2). Example 20

Octal Number System Uses eight digits, 0,1,2,3,4,5,6,7. Also called base 8 number system Each position in a octal number represents a 0


Hexadecimal Number System Uses 10 digits and 6 letters,

0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F. Letters represents numbers starting from 10. A = 10.

B = 11, C = 12, D = 13, E = 14, F = 15. Also called base 16 number system Each position in a hexadecimal number represents a 0



Decimal representation in computersDecimal Binary coded decimal

0 0000

1 0001

2 0010

3 0011

4 0100

5 0101

6 0111

7 1000

8 1001

9 00010000

10 00010001

11 00010010

12 00010011


Alphanumeric Representation

A set containing alphabets (in both cases), the decimal digits (1 0 in number) and special characters (roughly 10-15 in numbers) consist of at lea 70-80 elements. One such code generated for this set and is popularly used is ASCII (American National Standard Code for Information Interchange).

This code uses 7bits to represent 128 characters. Now an extended ASCII is used having 8-bit character representation code on Microcomputer.

Binary codes can be formulated for any set of discrete elements.


Computational Data Representation The computer is discrete digital and store information in

flip-flops, which are two state devices, in binary form. Basic requirements of the computational data

representation in binary form are: Representation of sign Representation of magnitude If the number is fractional then binary or decimal point and

exponent. The solution to sign representation is easy, because sign

can be either positive or negative, therefore, one bit can be used to represent sign. By default it should be the left most bit.

A number of n bits can be represented as n+1 bit number, where n+1th bit is the sign bit and rest n bits represent its magnitude.

To simplify the representation aspect two methods are suggested:

A) Fixed point representation• The fixed-point numbers bit 1 binary uses a sign bit. A positive number

have a sign bit 0, while the negative has a sign bit 1. In fixed-point numbers we assume that the positive of the binary point is at the end.

B) Decimal Fixed point representation• A decimal digit is represented as a combination of four bits; thus, a

four digit decimal number will require16 bits for decimal digits representation and additional 1 bit for sign.

C) Floating point representation• The first part of the number is a signed fixed point number, which is

termed as mantissa and the second part specifies the decimal or binary point position and is termed as an Exponent.

Summary

The five basic operations that a computer performs. These are input, storage, processing, output and control.

A computer accepts data as input, stores it, processes it as the user requires and provides the output in a desired format.

Computer system into three functional units i.e. Arithmetic logical unit (ALU), Control unit (CU), Central processing unit.

Number System

1.Data information

Technology

Transcript of 1.Data information