BASIC CONCEPTS OF

COMPUTERS PREPARED BY:

BAJAJ COACHING CENTER ROHTAKBCC2000.COM

COMPUTER

The 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

Bajaj C

oachin

g Cen

ter,RO

HT

AK

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

Bajaj C

oachin

g Cen

ter,RO

HT

AK

EVOLUTION OF COMPUTERS Blaise Pascal invented the first mechanical

adding machine in 1642 Charles Babbage is considered to be the

father of modern digital computersHe designed “Difference Engine” in 1822He designed a fully automatic analytical

engine in 1842 for performing basic arithmetic functions

His efforts established a number of principles that are fundamental to the design of any digital computer

Bajaj C

oachin

g Cen

ter,RO

HT

AK

SOME WELL KNOWN EARLY COMPUTERS The Mark I Computer (1937-44) The Atanasoff-Berry Computer (1939-42) The ENIAC (1943-46) The EDVAC (1946-52) The EDSAC (1947-49) Manchester Mark I (1948) The UNIVAC I (1951)

Bajaj C

oachin

g Cen

ter,RO

HT

AK

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

Bajaj C

oachin

g Cen

ter,RO

HT

AK

First generation computer

Period : 1945 – 1956

Inviter : Lee de Forest

Main processing device : Vacuum tubes

Bajaj C

oaching Center,R

OH

TAK

Vacuum tubesB

ajaj Coaching C

enter,RO

HTA

K

Punched curdsB

ajaj Coaching C

enter,RO

HTA

K

Large punched cards

Bajaj C

oaching Center,R

OH

TAK

. First generation computerAdvantages :

. 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 C

oaching Center,R

OH

TAK

Too bulky i.e. large in sizeB

ajaj Coaching C

enter,RO

HTA

K

Vacuum tubes burn frequentlyB

ajaj Coaching C

enter,RO

HTA

K

Maintenance problemsB

ajaj Coaching C

enter,RO

HTA

K

. Second generation computer

Period : 1956 – 1963

Inviter : William Shockley

Main processing device : Transistor

Storage media : Magnetic disc

Bajaj C

oaching Center,R

OH

TAK

Transistor

1 2

Bajaj C

oaching Center,R

OH

TAK

Second generation computer

Advantages :

. Size reduced considerably

. The very fast

. Very much reliable

Disadvantages :

. They over heated quickly

. Maintenance problems

Bajaj C

oaching Center,R

OH

TAK

Third generation computer

Period : 1964 – 1971

Inviter : Jack Kilby

Robert Noyce

Main processing device : IC (integrated circuit)

Storage media : Floppies

Bajaj C

oaching Center,R

OH

TAK

IC (integrated circuit)B

ajaj Coaching C

enter,RO

HTA

K

Third generation computer

Advantages :

. ICs are very small in size

. Improved performance

. Production cost cheap

Disadvantages :

. ICs are sophisticated

Bajaj C

oaching Center,R

OH

TAK

. Fourth generation computer

Period : 1971– present

Inviter : Ted Hoff

Main processing device : ICs with VLSI

(Very Large Scale Integration)

Storage media : Floppies, CDs.

Bajaj C

oaching Center,R

OH

TAK

ICs with VLSI(Very Large Scale Integration)

Bajaj C

oaching Center,R

OH

TAK

. Fifth generation computer

Period : present and beyond

Main processing device : ICs with parallel processing

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

Bajaj C

oaching Center,R

OH

TAK

. First generation computer. Second generation computer

. Third generation computer. Fourth generation computer

. Fifth generation computer

Vacuum tubes

Transistors

ICs ICs with VLSI

ICs with parallel processing

Bajaj C

oaching Center,R

OH

TAK

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

Bajaj C

oachin

g Cen

ter,RO

HT

AK

Characteristics Of A Computer

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.

Bajaj C

oachin

g Cen

ter,RO

HT

AK

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.

Bajaj C

oachin

g Cen

ter,RO

HT

AK

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 C

oachin

g Cen

ter,RO

HT

AK