Computer is an electronic machine that accepts input, processes it, and produces output quickly and efficiently. It has input devices like keyboards and mice, output devices like monitors and printers, and a processing device called the CPU. The CPU contains components like the ALU for calculations and MU for data storage. Generations of computers progressed from vacuum tubes to transistors to integrated circuits, increasing speed and capacity at each stage. Modern computers include desktop, portable, and specialized types that are used for different purposes.

1. COMPUTER
 Computer is an electronic machine which
accepts the input, process the input and
produces the output in fast and efficient way.

2. COMPONENTS OF COMPUTER
 Input Device
-Keyboard, Mouse, OMR(Optical Mark
Reader),OCR(Optical Character
Reader),MICR(Magnetic Ink Character
Recognition), Scanner
 Output Device
-Monitor, Printer
 Processing Device
-CPU(Central Processing Unit),ALU(Arithmetic &
Logic Unit),CU(Control Unit),MU(Memory Unit)

3. INPUT DEVICE
 Normal Keyboard having 108 keys.
 There are 3 types
i)Alphanumeric Keys-a-z,A-Z,0-9
ii)Function Keys – F1 – F12
iii)Special Keys – Alt, Ctrl, Del, Shift, Enter, Tab,
+,-,*,/$ etc....

4. MOUSE
(MECHANICALLY OPERATED USE SERIAL
ENGINE)
 Mouse was introduced in Stanford Research
Institute
 Types of Mouse
i)Mechanical Mouse-Movement is identified using
Roller ball
ii)Opto Mechanical Mouse-Movement is identified
using Light Sensitive optical device
iii)Optical Mouse-Movement is identified using
Laser light

5. CONTINUE…
Mechanical Mouse Opto Mechanical Mouse
Optical Mouse

6.  OMR is used in CET Exams to shade the answers.
 OMR sheets are valuated by OMR Machine after
written the exam.
OMR-OPTICAL MARK READER

7.  OCR is used in ATM machines to identify the pin numbers
entered by the customers when withdraw the amount.
OCR-OPTICAL CHARACTER READER

8. MICR
(MAGNETIC INK CHARACTER
RECOGNITION)
 It is used in bank cheques to write the check number
on it.

9. SCANNER
 It is used to scan the documents or photos.

10. OUTPUT DEVICE
MONITOR
 It is also called VDU(Visual Display Unit)
 It can be Monochrome or color Monitor
 CRT(Cathode Ray Tube),LCD(Liquid Crystal
Display),LED(Light Emitting Diode) are the types of
Monitor
 Resolution(Clarity), Size(17’,19’&20’) and Refresh
rate(Per minute how much of the image redrawn in
the monitor) are the 3 important things in Monitor
 Pixel(Picture Element) is used to support text based
and graphics based information.

11. MONITORS
CRT
LCD
LED

12. PRINTER
 It is used to give the output in paper format
 There are 2 types
Impact Printer :
Print Head & Inked Ribbon will be there to print
Produces noise while printing character
No need to use better quality paper
Clarity will not be good
Ex: Dot net & Daisy Wheel Printer
Non Impact Printer
Print Head & Inked Ribbon will not be there to print
Not Produces noise while printing character
Need to use better quality paper
Clarity will be good
Ex: Inkjet & Laser Printer

13. PRINTERS
IMPACT PRINTER - EXAMPLES
NON IMPACT PRINTER -
EXAMPLES
DotMatrix Printer
Daisy Wheel Printer
Inkjet Printer
Laser Printer

14. PROCESSING DEVICE
 CPU is used to do the process.
 ALU is used to do Mathematical operations.
 MU is used to store the datas.
 CU is used to control the overall Operation of the
CPU.

15. PROCESSING DEVICE
CPU MU
ALU
CU

16. HISTORY OF COMPUTER
 5000 years ago small pebbles were used in
olden days for counting purpose
 Joseph marie jacquard introduced
punched card in weaving clothes
 Later on Abacus was introduced for
counting
 Blaise Pascal introduced Pascal
Calculator to do 10 number of
Addition
 Gottfried Wilham Von improved the
pasaline calcilator to do
multiplicaion also
 Herman Hollerith introduced this
punched card in business world and
became very popular.
 He introduced the Tabulating Machine
Company(IBM)
 Charles Babbage introduced Difference
Engine(differential Equation) and
Analytical Engine(streaming)
 Clifford berry introduced a machine for
doing Boolean Algebra

17. CHARACTERISTICS OF COMPUTER
 Accuracy
 Speed
 Diligence
 Versatility
 Power of remembering
 Intangible benefits
 Storage Capacity
 Reduced Cost
 Time Saving

18. GENERATIONS OF COMPUTER
 First Generation Computers
 Second Generation Computers
 Third Generation Computers
 Fourth Generation Computers
 Fifth Generation Computers

19. FIRST GENERATION COMPUTER
 In this generation mostly they were used vacuum
tubes in the computer.
 They introduced ENIAC,EDVAC & UNIVAC
Computers.
 ENIAC (Electronic Discrete Variable Automatic
Computer)was introduced by John prosper eckert&
john W.Mauchly. It consists of 18000 vaccum tubes,
70000 resistors and 5 million soldered joints. We
need to spend 160 KW of electricity every day to
maintain this computers.

20. CONTINUE ….
 EDVAC (Electronic Discrete Variable Automatic
Computer)was introduced by John Von Neuman.
It is used for stored the programs.
 UNIVAC(Universal Automatic Computer) was
introduced by Remington rand company. It was
the first commercially available computer.

21. FIRST GENERATION-ENIAC

22. EDVAC

23. UNIVAC

24. SECOND GENERATION
 In 2nd generation, they were used transistors instead
of vacuum tubes.
THIRD GENERATION
 In this generation they were used IC’s(Integrated
Circuits) in the computer. IC was introduced by Jack
Kilby. They were used semiconductors also. If we fit
3 components in single chip, then it is called IC.If we
fit more than 3 components in single chip then it is
called Semiconductor.

25. 4TH & 5TH GENERATION
In 4th generation they were used LSI,VLSI&ULSI.
 If we fit 100’s components in single chip, then it is
called LSI(Large Scale Integration).
 If we fit 1000’s components in single chip, then it is
called VLSI(Very Large Scale Integration).
 If we fit million’s components in single chip, then it
is called ULSI(Ultra Large Scale Integration).
In 5th generation they will be try to use AI(Artificial
Intelligence) & Robots.

26. VACUUM TUBE TRANSISTOR IC

27. SEMI CONDUCTOR, LSI,VLSI,ULSI ,AI AND
ROBOTS

28. CLASSIFICATION OF COMPUTERS
1.Mini Computer.
2. Mainframe Computer.
3.Micro Computer – PC & Workstation
4.Super Computer.

29. DESKTOP & PORTABLE COMPUTERS

30. MEMORY AND ITS TYPES
RAM PROM
SRAM EPROM
DRAM
EEPROM
ROM