what is computer

1. INTRODUCTION
TO
INFORMATION
TECHNOLOGY
AND OPERATING
SYSTEM

2. CONTENTS
DATA vs. INFORMATION
WHAT IS A COMPUTER?
COMPUTER SYSTEMS
CLASSIFICATION OF COMPUTERS
EVOLUTION OF COMPUTERS
ARCHITECTURE OF COMPUTER

3. COMPUTER IS A PROGRAMMABLE,
MULTIPURPOSE MACHINE THAT
ACCEPTS DATA AND PROCESSES,
OR MANIPULATES IT INTO USEFUL
INFORMATION
WHAT IS A COMPUTER?
Raw Data Information

4. DATA
Data is encoded representation of
Information.
INFORMATION
Information is derived from data and
useful in solving problems.
DATA vs. INFORMATION

5. COMPUTER SYSTEM
SOFTWARE LIVEWAREHARDWARE
Input Devises
Output Devises
CPU
Backing Storage
System S/W Application S/W Operators
Programmers
System Analyst
Consultants
Languages Packagers
Pascal
VB
C+
Word Processing
Spread Sheets
Databases
Graphics

6. CLASSIFICATION OF COMPUTERS
( According to Size )
Personal Computers
Servers
Mainframe Computers
Supper Computers

7. EVOLUTION OF COMPUTER
• There had been 5 major
generations in the evolution of
computer. Each generation has
dramatically expanded its
processing power and storage
capabilities lowering the cost
simultaneously.

8. FIRST GENERATION (1946-1958)
Vacuum tubes for internal operations.
Low-Level languages for programming (machine
language).
Magnetic drums for primary memory.
Primary memory limited.
Heat and maintenance problems.
Punch cards for input and outputs.
Slow input and output.
Speed upto 10,000 inst/sec.
Large in size. e.g. UNIVAC 1, EDVAC

9. SECOND GENERATION (1958-1964)
Transistors for internal operations.
Increased use of high-level languages.
Magnetic cores for primary memory.
Increased memory capacity.
Binary coded data.
Increasing processing speed.
Magnetic tapes and disks for secondary storage.
Speed up to 200,000-300,000 inst/sec.
e.g. IBM 1620, univac 1108.

10. THIRD GENERATION (1965-1970)
Integrated circuits (ICs) on silicon chips for internal operations.
Increased memory capacity.
Common use of minicomputers.
Emergence of software industry.
Reduction in size and cost.
Increase in speed and reliability. HONEY WELL-6000 SERIES
Speed up to 5 million inst/sec.
Use of operating systems that automated the running of
programs & communications between CPU & peripheral devices.
Availability of hardware independent programming languages &
less technical skill required.

11. FORTH GENERATION (1971-TODATE)
Large Scale Integrations (LSI) and Very Large Scale (VLSI) for
internal operations.
Development of the microprocessor.
Introductions of micro and super computers.
Increase in speed, power and storage capacity.
Parallel processing.
Artificial intelligence and expert systems.
Robotics.
Increased use of Micro/Personal Computers.
e.g. Apple II, IBM PC, Micro Computers.

12. FIFTH GENERATION
Artificial Intelligence (AI) computers are in developing stage.
Artificial intelligent computers will be able to converse with
people in a human like manner

13. ARCHITECTURE
OF
A COMPUTER

14. MAIN PARTS OF A COMPUTER
INPUT
PROCESSING
OUTPUT
KEY BOARD
MOUSE
BAR CODE
READER
VOICE DEVICE
SCANNERS
LIGHT PEN
MONITOR
PRINTER
PLOTTER
SPEAKER
MICRO PROCESSOR

15. SOFTWARE
THE PROGRAMS THAT DRIVE THE HARDWARE OF A
COMPUTER SYSTEM IS SOFTWARE
SYSTEM SOFTWARE
APPLICATION SOFTWARE

16. SYSTEM SOFTWARE
A SET OF PROGRAMS WHICH CONTROLS AND
CONTRIBUTES TO THE IMPROVEMENT OF
PERFORMANCE OF COMPUTER.
ex. MS DOS, WINDOWS 95, UNIX

17. APPLICATION SOFTWARE
THE PROGRAMS WRITTEN TO DO SPECIFIC JOBS
FOR THE USER
ex. PAYROLL SYSTEMS, ACCOUNT SYSTEMS

18. OPERATING
SYSTEM

19. OPERATING SYSTEM
UNABLE TO COMMUNICATE
USER
CAN UNDERSTAND ONLY
HUMAN BEING
LANGUAGE
Ex. ENGLISH, SINHALA,
ETC.
COMPUTER
PROCESSOR
CAN UNDERSTAND ONLY
MACHINE (BINARY)
LANGUAGE

20. WINDOWS
• WINDOWS 3.11
• WINDOWS 95
• WINDOWS 98
• WINDOWS 2000
• WINDOWS XP
• WINDOWS Vista