Introduction, History, Classification, Characteristics and Application of Computer

1. Introduction to Computer
Er. Sharad Kafle

2. Computer System
Er. Sharad Kafle

3. Introduction
●Machine that performs
calculations and processes
Information.
●List of Instructions
●Quick and accurate
●Integral part of our life
Common Characteristics:
● Word Length
● Speed
● Storage
● Accuracy
● Versatility (Very simple to
complex)
● Automation
● Diligence (Free of tiredness,
Continuous concentration and
so on)
Data Information
Processing
Er. Sharad Kafle

4. Digital and Analog Computer
DIGITAL COMPUTERS
 Input as discrete quantities
 More Versatile
 More Accurate
 Less Complex
 Works on numbers (0 , 1)
Eg. All Modern Computers,
calculators
ANALOG COMPUTERS
Input as continuously
changeable physical quantities
(electrical, mechanical, etc)
Less Versatile
Less Accurate
More Complex
Dependent on multiple factors
Eg. Op-amps, altimeters,
speedometer, etc
Er. Sharad Kafle

5. Characteristics of Computer
1. Word Length
 Number of bits the computer can process at a time in parallel.
 Commonly used : 8, 16, 32 or 64 bits
 The longer the word length, the more powerful is the computer.
32- bit computer means ??
Er. Sharad Kafle

6. Characteristics of Computer
2. Speed
 Rate of instructions executed per seconds.
 Modern computers speed are measured in nano-pico seconds.
 Millions of instructions are executed in a second.
Er. Sharad Kafle

7. Characteristics of Computer
3. Storage
 Main Memory
 Auxiliary Memory
4. Accuracy
 Error detection and Correction techniques
 Hardware errors
 Errors due to human factors
 GIGO
Er. Sharad Kafle

8. Characteristics of Computer
5. Versatility
Simple to highly complex computations
6. Automation
Simple to highly complex computations
Not as simple as it is seen.
Computer performs lots of calculations until it obtains the result.
Er. Sharad Kafle

9. Characteristics of Computer
7. Diligence
 Being constant and earnest in effort and application.
 कहिल्यै नथाक्ने, अनवरत
 No Depression, No Lack of Concentration
 Same speed and same accuracy for millionth of times.
Er. Sharad Kafle

10. History of Computer
Stones and Sticks : First Counting Devices used by people
 ABACUS : Subtract, Multiply and Divide
: China, Japan and Korea still use ABACUS.
 PASCALINE : Blaise Pascal
: Upto 9 Digits.
 JACKQUARD’s LOOM
Er. Sharad Kafle

11. History of Computer
Difference Engine
 Produces Table of Numbers
that the ship navigator uses
during navigation.
Er. Sharad Kafle

12. History of Computer
Er. Sharad Kafle

13. Generations of Computer
Based on the period of development and the features incorporated
 First Generation Computers (1945-1955)
 Second Generation Computers (1957-1963)
 Third Generation Computers (1964-1971)
 Fourth Generation Computers (1972 onwards)
 Fifth Generation Computers (Present and Future)
Er. Sharad Kafle

14. First Generation Computer
Based on the period of development and the features incorporated
1945-1955
 First Digital Computer using Vacuum Tubes
 Machine Language (not assembly and high level)
 ENIAC
 EDVAC (1947) : greater versatility due to stored program as well as data
 UNIVAC I (1951)
 Vacuum Tubes(More Size)
 Magnetic Drums (Storage)
Er. Sharad Kafle

15. Second Generation Computer
Based on the period of development and the features incorporated
1956-1963
 Invention of Transistor (Replaced large Vacuum Tubes)
 Smaller, faster, more reliable and energy efficient
 Used Assembly Language
 Stored Program (Instruction were held inside the computer memory)
 IBM 1401
Er. Sharad Kafle

16. Third Generation Computer
Based on the period of development and the features incorporated
1964-1971
 Transistor produced heat damaging sensitive part.
 Inauguration of IC (1958).
 Computer became more Smaller, faster, more reliable and energy efficient
 Inauguration of OS, that allowed machines to run many programs at once
with a central monitoring system.
Er. Sharad Kafle

17. Fourth Generation Computer
Based on the period of development and the features incorporated
1972 onwards
 Size considerably reduced
 LSI, VLSI : sequenced 1000s of components onto a chip
 ULSI : increased to millions.
 IBM introduced PC, Apple’s Macintosh, GUI, etc.
 Number of computers were built and kept at a place : need of network.
 Inception of WWW
Er. Sharad Kafle

18. Fifth Generation Computer
Based on the period of development and the features incorporated
 Present and future.
 Artificial Intelligence (AI)
 Super Large Scale Integration (SLSI)
 Large Number of Processes Grouped into :
1. Knowledge Base System : Set of Processors, databases.
2. Inference System : Draws reasoned conclusion from KBS
: lips (logical inferences per second)
3. Intelligent User Interface
: Interface between computer and user.
: extensive graphics and Image processing
Er. Sharad Kafle

19. Classifications of Computer
1. Microcomputers
2. Minicomputers
3. Mainframes
4. Super Computers
Network Computers
IncreaseinSize
Er. Sharad Kafle

20. Microcomputers
 General Purpose Computers
 Least Expensive
 Ranges from palmtops to desktop (PC).
 Microprocessor is the core part of
Microcomputers which forms the CPU.
Er. Sharad Kafle

21. Minicomputer
 Intermediate between microcomputers and mainframe in terms of size.
 For Process control, engineering applications and scientific research.
 IBM is market leader in minicomputers with its AS/400 series of
computers.
 DDP – Distributed Data Processing i.e. decentralized processing across
different computers.
 Microcomputers are inadequate in processing power and peripheral
connections to complete the work while mainframes are too expensive for
that.
Er. Sharad Kafle

22. Mainframes
 High Performance computers : Large scale computing purpose
 Large Databases
 Several Million program Instructions per Second (MIPS).
 Typically hundred or thousands or online computers can be linked to the
mainframe.
 Insurance Companies, Bank, Airline, Railway, etc.
 Popular IBM models : 3090, ES/9000, S/390, Z800, etc.
Er. Sharad Kafle

23. Supercomputers
 Computers with highest
processing power.
 Primary application in scientific
and military purpose.
 Complex calculations,
simulations, image processing,
etc.
 4 to 10 times faster than
mainframes.
Er. Sharad Kafle

24. Computer System
Er. Sharad Kafle

25. Computer System
1. Input
2. Processor
3. Secondary Storage
4. Output
Er. Sharad Kafle

26. Computer System
Microprocessor
 Built onto a single piece of silicon, known as wafer or chip.
 Developed form of IC using s/c technology.
 Serves as CPU in the general purpose computers.
Er. Sharad Kafle

27. Computer System
Central Processing Unit
a) Control Unit
 Access Program Instruction
 Decode instruction
 Controls flow of data throughout the system
 Data flows passes through path called buses.
b) Arithmetic-Logic Unit
 Performs computation and comparison on data.
Er. Sharad Kafle

28. Computer System
Central Processing Unit
c) Registers
 High Speed storage area.
 Hold Data and instruction
d) Main memory
 Stores instruction from program
 Stores data to be processed.
Er. Sharad Kafle

29. Applications of Computer
• Medical Application
• Educational Application
• Virtual Reality
• Simulation
• Military
• Industrial Application
• Telecommunication, etc.
Er. Sharad Kafle

30. Thanks!
Er. Sharad Kafle
Institute of Engineering, Tribhuwan University
Web : www.skafle.com.np
FB : www.facebook.com/kaflesharad
Email : kaflesharad@hotmail.com
kaflesharad@rocketmail.com