b asic c oncepts o f c omputers bajaj coaching center, rohtak for more such slides visit bcc2000.com

BASIC CONCEPTS OF COMPUTERS

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For more such slides visit bcc2000.com

COMPUTERThe word computer comes from the word

“compute”, which means, “to calculate”.Thereby, a computer is an electronic device that

can perform arithmetic operations at high speed.A computer is also called a data processor

because it can store, process, and retrieve data whenever desired.

Data is a raw material used as input to data processing and information is processed data obtained as output of data processing.

DATA PROCESSING

The activity of processing data using a computer is called data processing.

Data

Capture Data

Manipulate Data

Output Results

Information Data is raw material used as input and information is

processed data obtained as output of data processing.

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EVOLUTION OF COMPUTERS

Blaise Pascal invented the first mechanical adding machine in 1642.

Charles Babbage is considered to be the father of modern digital computers.He designed “Difference Engine” in 1822He designed a fully automatic analytical engine in

1842 for performing basic arithmetic functionsHis efforts established a number of principles that are

fundamental to the design of any digital computer.

SOME WELL KNOWN EARLY COMPUTERS

The Mark I Computer (1937-44) – also known as Automatic Sequence

Controlled Calculator.

The Atanasoff-Berry Computer (1939-42)

The ENIAC (1943-46)- The Electronic Numerical Integrator and

Calculator was the first all electronic computer.

The EDVAC (1946-52)- Electronic Discrete Variable Automatic

Computer.

The EDSAC (1947-49)- The Electronic Delay Storage Automatic

Calculator.

The UNIVAC I (1951)- Universal Automatic Computer.

COMPUTER GENERATIONS

“Generation” in computer talk is a step in technology. It provides a framework for the growth of computer industry.

Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software.

Till today, there are five computer generations.

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First generation computer

Period : 1942 – 1955

Main processing device : Vacuum tubes

All data and instructions were fed into the system from punched cards.

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Vacuum tubes

Punched cards

Large punched cards

First generation computer

Advantages :

. It was only electronic device

. First device to hold memory

Disadvantages :

. Too bulky i.e. large in size

. Vacuum tubes burn frequently

. They were producing heat

. Maintenance problems Bajaj Coaching Center, Rohtak

Too bulky i.e. large in size

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Vacuum tubes burn frequently

Maintenance problems

Second generation computer

Period : 1955 – 1964

Inviter : William Shockley

Main processing device : Transistor

Storage media : Magnetic disc

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Transistor

1 2

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Second generation computerAdvantages : • Size reduced considerably

• Faster than first generation computers

• Very much reliable.

• Consumed less power and dissipated less heat.

• Easier to program and use than the first generation computers.

Third generation computer

Period : 1964 – 1975

Inviter : Jack Kilby

Robert Noyce

Main processing device : IC (integrated circuit)

Storage media : Floppies

IC (integrated circuit)

Third generation computer

Advantages :

. ICs are very small in size

. Improved performance

. Production cost cheap

Disadvantages :

. ICs are sophisticated

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Fourth generation computer

Period : 1975– present

Inviter : Ted Hoff

Main processing device : ICs with VLSI

(Very Large Scale Integration)

Storage media : Floppies, CDs.

ICs with VLSI(Very Large Scale Integration)

Fifth generation computer

Period : present and beyond

Main processing device : ICs with parallel processing

Storage media : Video disksAdvantages : . Artificial intelligence . Expert system

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. First generation computer. Second generation computer

. Third generation computer. Fourth generation computer

. Fifth generation computer

Vacuum tubes

Transistors

ICs Microprocessors

ICs with parallel processing

Computer is a group of electronic devices used to process the data.

The characteristics of a computer are:

4. Accuracy5. Automation 6. Functionality 7. Tirelessness

1. Speed 2. Reliability 3. Memory capacity

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1.Speed: computer process the data at an unimaginable speed. The speed of the computer ranges up to Nano seconds.

2. Reliability: The next important characteristic of a computer is its reliability. we can always rely on the information given by a computer.

3. Memory capacity: The memory capacity of a computer is measured in in bits and bytes. Large amount of the data can be stored in computer and retrieved. Memory capacity of the computer ranges in Giga bytes.

4. Accuracy: Accuracy of the computer is very high it performs calculation with greater accuracy

in less time.

5. Automation: a computer allows automation for any process designed in the from of a program. A program can be executed any number of times to repeat the process.

6. functionality: computer can performs many kinds

of jobs. They not process the data but also can be

Used for plying music, movies, and printing jobs.

It finds its applications in all most all the fields.

7. Tirelessness: A computer never gate tired. Bajaj Coaching Center, Rohtak