The document provides an introduction to computers, detailing their basic operations such as input, processing, output, and storage, along with the difference between data and information. It outlines the evolution of computer generations from the first generation using vacuum tubes to the current focus on artificial intelligence and ultra-large scale integration circuits. Additionally, it discusses the advantages and disadvantages of computers, various applications, and a classification of computer hardware and software components.

1. An Introduction to Computer
1
C.SURYA
Assistant Professor/CSE
Sri Ramakrishna College of Engineering
Perambalur.

3. What is Computer?
3
The computer is an electronic device that accepts
data, performs operations on that data , presents
the results, and stores the data or results as
needed.

4. Basic Operations of Computer
1.
2.
3.
4.
It perform four primary operations are:
INPUT – entering data into the computer
PROCESSING – performing operations on
the data
OUTPUT – presenting the results
STORAGE – saving data, or output for future
use.

5. 4
Data
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Data is a collection of facts, figures and
statistics related to an object.
Data can be processed to create useful
information.
Data is a valuable asset for an organization.

6. Information
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The manipulated and processed form of data is
called information.
It is more meaningful than data. It is used for
making decisions.
Data is used as input for processing and
information is used as output of this processing.
6

7. Data Vs. Information
DATA INFORMATION
It is a raw fact about an object. It is the processed data.
It has no meaning. It has meaning.
Eg. Ram, 10. Eg. Ram’s age is 10.
Or
Ram’s mark is 10.

8. Characteristics of Computer
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Speed
Storage
Spontaneous (automatic)
Consistency
No feelings
Communications
Diligence

9. Things Get to Know about Computer ?
????
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Generation of computer
Basic organization of computer
Classification of computer
Computer Languages

10. 10
Generations of Computers
Computers can be divided into 5 upon the technologies used.
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First Generation (1942 - 1955)
Second Generation (1955 - 1964)
Third Generation (1964 - 1975)
Fourth Generation (Since 1975)
Fifth Generation (Since 1980)

11. 11

12. First Generation Computers
(1942 - 1955)
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The vacuum tube technology was used in first-
generation computers.
Mark-1m, ENIAC, EDSAC, EDVAC, UNIVAC-1 etc.
The machine language only was used in first-generation
computers.
Advantages are :
These computers were the fastest of their time.
They were programmed using machine language.

13. Disadvantages
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Unreliable Very costly
Generate lot of heat Huge size
Need of A.C. Non portable
Consumed lot of electricity
Constant (or frequent) maintenance
required

14. 14

15. 15
Second Generation Computers
(1955 - 1964)
• This generation using the transistor were cheaper,
consumed less power, more compact in size, more
reliable and faster than the first generation machines
made of vaccum tubes.
Advantages are :
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Use of transistors
Smaller size as compared to First generation
computers
Generate less heat as compared to First generation
computers
Consumed less electricity as compared to First
generation computers

16. Disadvantages
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Still very costly
A.C. needed
Constant (or frequent) maintenance required

17. 17

18. Third Generation Computers
(1964 - 1975)
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The third generation of computer is marked by the
use of Integrated Circuits (IC's) in place of transistors.
A single I.C has many transistors, resistors and
capacitors.
This development made computers smaller in size,
reliable and efficient.
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19. 19
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More reliable
Smaller size
Generate less heat
Faster
Lesser maintenance
Consumed lesser electricity
Disadvantages are:
Still costly
A.C needed
Advantages are :

20. 20

21. Fourth Generation Computers
(1975 onwards)
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The fourth generation of computers is marked by the use of
Very Large Scale Integrated (VLSI) circuits.
As a result, it gave rise to personal computer (PC) revolution.

22. 22
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Very cheap
Portable and reliable
Smaller in size
Production cost is very low
Very high processing speed
Very large internal and external storage capacity
•
Disadvantages are:
Highly sophisticated technology required for the
manufacturer of microprocessor chips
Advantages:

23. 23

24. Fifth Generation Computers
(In process)
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The main features of Fifth Generation
are:
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ULSIC (Ultra Large Scale Integration Circuits )
technology Development of true artificial intelligence
Advancement in Parallel Processing
More user friendly interfaces with multimedia
features Very powerful and compact computers at
cheaper rates

25. Advantages of Computer
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Easy processing of complex tasks.
It saves time by quick manipulation of data as
compared to when done manually.
The errors in data processing are minimized when a
computer is used.
It has helped in making communication easier by using
internet.
It stores, retrieves, and processes a large amount of
data. It helps in multitasking of various jobs.
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26. Disadvantages of Computer
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Un-Employment Cyber-crime
Computer can perform only what is it programmed
to do.
Computer need well defined instructions to perform
any operation

27. Applications of Computer
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Education
Entertainment
Science
Publishing
Agriculture
Government
Home

28. Computer System
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The computer along with various units and software that
performs different activities in data processing are
collectively known a computer system.
A computer system is divided into two sub- systems:
1.
2.
Computer Software
Computer Hardware

29. Computer Software
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A set of instructions given to the computer in machine code
that tells the computer what to do and how to perform the
given task of the user is known as computer software.
The software is developed in computer programming
languages.
You can not feel, touch or see software inside the computer
memory.
The Computer software is classified into two main
categories: 1.Application software.
2.System software.

30. Computer Hardware
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2.
3.
4.
The physical parts of a computer are known as computer
hardware.
The hardware consists of electronic circuits and mechanical
equipment etc. used to perform various functions in the
computer.
The H/w componentsare:
1.Input devices
Output devices
Central Processing Unit (CPU)
Memory unit
5.Storage devices

32. Input Unit
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Input is any data or instructions entered into the computer in
the form of signals. The input into the computer can be
entered:
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Through keyboard (by typing characters).
By selecting commands (icons) on the screen and then
clicking with mouse.
By pressing finger on touchscreen.
By speaking into a microphone.
By scanning data printed on paper through scanner etc.
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33. 42
Input Devices
Now-a-days, the commonly used input devices are:
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Keyboard Mouse Scanner Microphone
Digital Camera
Optical Bar Code Reader
Optical mark recognition (OMR) Touch
Screen
Joystick
Magnetic Ink Character Recognition (MICR)

34. 48
Output Devices
• An output device is a hardware component used to get
output from the computer.
OUTPUT DEVICES
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Monitor
Plotter
Speaker
Printer

35. Central Processing Unit (CPU)
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Central Processing Unit (CPU) consists of the
following features −
CPU is considered as the brain of the computer.
CPU performs all types of data processing operations.
It stores data, intermediate results, and instructions
(program).
It controls the operation of all parts of the computer.

36. Components of CPU
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CPU itself has following 3 components.
Memory or Storage Unit
Control Unit
ALU(Arithmetic Logic Unit)

37. Memory Unit
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Memory unit is the amount of data that can be stored in
the storage unit. This storage capacity is expressed in
terms of Bytes.

38. RAM Vs. ROM

39. Control Unit
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Functions of control unit are −
It is responsible for controlling the transfer of data and
instructions among other units of a computer.
It manages and coordinates all the units of the
computer.
It obtains the instructions from the memory, interprets
them, and directs the operation of the computer.
It communicates with Input/Output devices for
transfer of data or results from storage.
It does not process or store data.

40. Arithmetic & Logic Unit (ALU)
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Arithmetic section is to perform arithmetic
operations like addition, subtraction,
multiplication, and division.
Logic section is to perform logic
operations such as comparing, selecting,
matching, and merging of data.

41. Types of Computers
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• Computers can also be divided into three categories
depending upon their instruction and form of input
data that they accept and process. These are:
AnalogComputers
DigitalComputers Hybrid
Computers

42. Analog Computers
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It means that these computers accept input and
give output in the form of analog signals. The
output is measured on a scale.
The analog computers are used to measure the
continuous values.
Eg.The thermometer
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43. Digital Computers
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The digital computer is designed using digital circuits in
which there are two levels for an input or output signal.
These two levels are known as logic 0 and logic 1.
Digital Computers can give more accurate and faster
results.

44. 70
Depending upon their speed and memory size, computers
are classified into following four main groups.
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Supercomputer
Mainframe computer
Mini computer
Microcomputer
Desktop computer
Laptops
Hand-held (PDA)
Classification of Digital computers

45. Computer Languages
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Python
C, C++, C#
Java, JavaScript, JSP
Java Servlet Page(JSP)
HTML, XML, PHP
HyperText Markup Lang.(HTML)
Extensible Markup Lang.(XML)
Hypertext PreProcessor(PHP)
SQL – Structured Query Lang.(SQL)
COBOL- Common Business Oriented Lang.
PASCAL, etc