BBA-II-Intro To Computers.pptx

8/18/2019 BBA-II-Intro To Computers.pptx

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BASIC CONCEPTS OF

COMPUTERS

Unit I


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WHAT IS A COMPUTER?

A computer:

Is an electronic device

Operating under the control of instructions

(software) stored in its own memory unit,That can accept data (input),

Manipulate data (process), and

Produce information (output)

Generally, the term is used to describe acollection of devices that function together as a

system.


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DEVICES THAT COMPRISE A

COMPUTER SYSTEM

Printer

(output)

Monitor

(output)Speaker

(output)

Scanner

(input)

Mouse

(input)

Keyboard

(input)

System unit

(processor, memory…)

Storage devices

(CD-RW, Floppy,Hard disk, zip,…)


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CHARACTERISTICS OF COMPUTERS

Speed:Computer is very fast and accurate device.It can process millions and millions of instructionswithin seconds.

Accuracy:Computer results are highly accurate.

Memory:Computers have a large amount of memory to hold avery large amount of data or information.

Programmed Intelligence:Computer themselves as such are dumb terminals.But they are programmed in such a way that they canperform those operations which have been fed intothem in the form of executable programs.


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CHARACTERISTICS OF COMPUTERS

Diligence:Computer is free from problems like lack of

concentration, and confusions etc.

Computer may never be confused like humans.

Versatility:We can perform many different types of tasks on

computer.

One moment it might be busy in calculating the

statistical data for annual performance evaluation of a

business organization and next moment it might beworking on playing movies.

Power of Remembrance:Unlike humans, computer can store things for unlimited

period of time.


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WHAT DOES A COMPUTER DO?

Computers can perform five general operations,

which comprise the information processing cycle.

Input

Process Output

Storage

Control


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DATA AND INFORMATION

All computer processing requiresdata, which is a

collection of raw facts, figures and symbols, such as

numbers, words, images, video and sound, given to

the computer during the input phase.

Computers manipulate data to create information.

Information is data that is organized,

meaningful, and useful.

During theoutput Phase, the information that

has been created is put into some form, such as a

printed report.

The information can also be put in computer

storage for future use.


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HOW DOES A COMPUTER KNOW

WHAT TO DO?

It must be given a detailed list of instructions,

called acomputer program orsoftware, that

tells it exactly what to do.

Before processing a specific job, the computer

program corresponding to that job must be stored

inmemory.

Once the program is stored in memory the

computer can start the operation byexecuting

the program instructions one after the other.


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WHAT ARE THE PRIMARY

COMPONENTS OF A COMPUTER ?

Input devices.

Central Processing

Unit (containing the

control unit and the

arithmetic/logic unit).

Memory.

Output devices.

Storage devices.

These are also known as theFunctional

Componentsof a Computer!


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BLOCK DIAGRAM OF COMPUTER

SYSTEM

SecondaryMemory

PrimaryMemory

Control Unit

Arithmetic LogicUnit

InputUnit

OutputUnit

Program &Data

Resul

ts

Storage Unit

Central

Flo o!

ControlFlo o!Data


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FUNCTIONS OF INPUT UNIT

Links the external environment with the computer

system.

Accepts or reads the instructions and data from

the outside world.

Converts these instructions and data into

computer acceptable form (Binary Codes).This transformation is accomplished by units called

input interfaces.

Supplies the converted instructions and data to the

computer system for further processing.


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FUNCTIONS OF OUTPUT UNIT

Links the computer system with the external

environment

Accepts the result produced by the computer (in

binary codes).

Converts these results into human readable form.This transformation is accomplished by units called

output interfaces.

Supplies the converted results to the outside world.


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FUNCTIONS OF STORAGE UNIT

Provides space for storing:Data and instructions required for processing, and

received from input devices.

Intermediate results of processing.

Final results of processing, before they are released toan output device.


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FUNCTIONS OF ARITHMETIC/LOGIC

UNIT

It is the place where actual execution of instructions

takes place, during the processing operation.

Calculations are performed and all comparisons are

made in the ALU.

The data and instructions stored in the primary

memory, are transferred as and when needed to the

ALU.

Intermediate results generated by the ALU are

temporarily transferred back to the primary memory.Hence, data may move from primary memory to

ALU, and back again to memory, many times before

processing is over.


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FUNCTIONS OF CONTROL UNIT

It does not perform any actual processing of data.

But it acts as a central nervous system for other

components of the computer system.

It manages and coordinates the entire computersystem.

It obtains instructions from the program stored in

main memory, interprets the instructions, and

issues signals.

These signals cause other units of the system to

execute the instructions.


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FUNCTIONS OF CENTRAL

PROCESSING UNIT

The Control Unit and Arithmetic Logic Unit are

jointly known as the Central Processing Unit of the

system.

The CPU is the brain of a computer system.

In a computer system, all major calculations are

performed inside the CPU.

The CPU is responsible for activating and

controlling the operations of other units of the

computer system.

BBA-II-Intro To Computers.pptx

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