The document provides an extensive overview of computers, covering definitions, characteristics, hardware and software components, historical advancements, and the evolution of computing technology. It details the transition from early mechanical systems to modern microprocessors, the significance of operating systems, and various input/output devices. Additionally, it outlines the essential characteristics of computers including speed, accuracy, versatility, and storage capabilities.

1. C R I T I C A L U N D E R S T A N D I N G O F I C T
Course-3 Module-2

2. Syllabus
 Computer - Definition, Characteristics & Types of Computer – Speed, Storage,
Accuracy, Versatile, Automation, Diligence
 Hardware and uses-
 Input devices - Key Board, Mouse, Scanner, Microphone, Digital camera.
 Output devices - Monitor, Printer, Speaker, Screen image projector
 Storage devices - Hard Disk, CD & DVD, Mass Storage Device (Pen drive)
 ICT Tools- Touch screen, Personal Digital Assistants (PDA), Bar Code Readers,
LCD Projectors, Game Pads and Joy Sticks.
 Software’s and its uses in Education.
 Operating System - Concept and function.
 Application Software
 Word Processors
 Presentation software
 Data management -Spread sheet
 Content access software –Media Player,
 Media development software-Image Editing Software

3. Definition of Computer
 Simplest definition of a computer:
A device that processes input and generates
output

4. Definition of a Computer
 Information Processor
 Input and Output

5. Definition of Modern Computer
 Inputs, outputs, processes and stores information
 Physical: Keyboard, monitor, etc. – are these
necessary components?

6. History of Computers - Long, Long Ago
 beads on rods to count and calculate
 still widely used in Asia!

7. History of Computers - Way Back When
• Slide Rule 1630
• based on Napier’s rules for
logarithms
• used until 1970s

8. History of Computers - 19th Century
 first stored program -
metal cards
 first computer
manufacturing
 still in use today!

9. Charles Babbage - 1792-1871
 Difference Engine c.1822
 huge calculator, never finished
 Analytical Engine 1833
 could store numbers
 calculating “mill” used punched
metal cards for instructions
 powered by steam!
 accurate to six decimal places

10. Discussion Question
 What was the biggest advance that led to modern
computers?
 Electricity
 Transistor
 Microchip
 Data storage

11. Vacuum Tubes - 1941 - 1956
 First Generation Electronic
Computers used Vacuum
Tubes
 Vacuum tubes are glass tubes
with circuits inside.
 Vacuum tubes have no air inside
of them, which protects the
circuitry.

12. UNIVAC - 1951
 first fully electronic
digital computer built
in the U.S.
 Created at the
University of
Pennsylvania
 ENIAC weighed 30
tons
 contained 18,000
vacuum tubes
 Cost a paltry $487,000

13. Grace Hopper
 Programmed UNIVAC
 Recipient of Computer
Science’s first “Man of the
Year Award”

14. First Computer Bug - 1945
 Relay switches
part of computers
 Grace Hopper
found a moth
stuck in a relay
responsible for a
malfunction
 Called it
“debugging” a
computer

15. First Transistor
 Uses Silicon
 developed in 1948
 won a Nobel prize
 on-off switch
 Second Generation
Computers used
Transistors,
starting in 1956

16. Second Generation – 1965-1963
 1956 – Computers began to incorporate
Transistors
 Replaced vacuum tubes with Transistors

17. Integrated Circuits
 Third Generation Computers used Integrated Circuits
(chips).
 Integrated Circuits are transistors, resistors, and
capacitors integrated together into a single “chip”

18. Operating System
 Software – Instructions for Computer
 Operating system is set of instructions loaded each
time a computer is started
 Program is instructions loaded when needed

19. Third Generation – 1964-1971
 1964-1971
 Integrated Circuit
 Operating System
 Getting smaller, cheaper

20. The First Microprocessor – 1971
 The 4004 had 2,250
transistors
 four-bit chunks (four 1’s or
0’s)
 108Khz
 Called “Microchip”

21. What is a Microchip?
 Very Large Scale Integrated Circuit (VLSIC)
 Transistors, resistors, and capacitors
 4004 had 2,250 transistors
 Pentium IV has 42 MILLION transistors
 Each transistor 0.13 microns (10-6 meters)

22. 4th Generation – 1971-present
 MICROCHIPS!
 Getting smaller and smaller, but we are still using
microchip technology

23. Birth of Personal Computers - 1975
 256 byte memory (not
Kilobytes or
Megabytes)
 2 MHz Intel 8080
chips
 Just a box with
flashing lights
 cost $395 kit, $495
assembled.

24. Generations of Electronic Computers
First
Generation
Second
Gen.
Third
Gen.
Fourth Gen.
Technology Vacuum
Tubes
Transistors Integrated
Circuits
(multiple
transistors)
Microchips
(millions of
transistors)
Size Filled Whole
Buildings
Filled half a
room
Smaller Tiny - Palm
Pilot is as
powerful as
old building
sized
computer

25. Over the past 50 years, the Electronic
Computer has evolved rapidly.
Connections:
 Which evolved from the other, which was an
entirely new creation
 vacuum tube
 integrated circuit
 transistor
 microchip

26. Evolution of Electronics
Vacuum
Tube
Transistor
Integrated
Circuit
Microchip
(VLSIC)

27. Evolution of Electronics
 Vacuum Tube – a dinosaur without a modern
lineage
 Transistor  Integrated Circuit  Microchip

28. IBM PC - 1981
 IBM-Intel-Microsoft joint
venture
 First wide-selling personal
computer used in business
 8088 Microchip - 29,000
transistors
 4.77 Mhz processing speed
 256 K RAM (Random Access
Memory) standard
 One or two floppy disk drives

29. Apple Computers
 Founded 1977
 Apple II released 1977
 widely used in schools
 Macintosh
 released in 1984, Motorola 68000
Microchip processor
 first commercial computer with
graphical user interface (GUI)
and pointing device (mouse)

30. Computers Progress
UNIVAC
(1951-1970)
(1968 vers.)
Mits Altair
(1975)
IBM PC
(1981)
Macintosh
(1984)
Pentium IV
Circuits Integrated
Circuits
2 Intel 8080
Microchip
Intel 8088
Microchip -
29,000 Transistors
Motorola
68000
Intel P-IV
Microchip - 7.5
million transistors
RAM
Memory
512 K 265 Bytes 256 KB 256 MB
Speed 1.3 MHz 2 KHz 4.77 MHz 3200 MHz
= 3.2 GHz
Storage 100 MB Hard
Drive
8” Floppy
Drive
Floppy Drive Floppy
Drives
Hard Drive,
Floppy, CD-
Rom
Size Whole Room Briefcase
(no monitor)
Briefcase +
Monitor
Two
shoeboxes
(integrated monitor)
Cost $1.6 million $750 $1595 ~$4000 $1000 -
$2000

31. 1990s: Pentiums and Power Macs
 Early 1990s began penetration of computers into
every niche: every desk, most homes, etc.
 Faster, less expensive computers paved way for
this
 Windows 95 was first decent GUI for “PCs”
 Macs became more PC compatible - easy file
transfers
 Prices have plummeted
 $2000 for entry level to $500
 $6000 for top of line to $1500

32. 21st Century Computing
 Great increases in speed, storage, and memory
 Increased networking, speed in Internet
 Widespread use of CD-RW
 PDAs
 Cell Phone/PDA
 WIRELESS!!!

33. What’s next for computers?
 Use your imagination to come up with what the next
century holds for computers.
 What can we expect in two years?
 What can we expect in twenty years?

34. Basic characteristics
 1. Speed: - As you know computer can work very
fast. It takes only few seconds for calculations that
we take hours to complete. You will be surprised to
know that computer can perform millions
(1,000,000) of instructions and even more per
second.
 Therefore, we determine the speed of computer in
terms of microsecond (10-6 part of a second) or
nanosecond (10 to the power -9 part of a second).
From this you can imagine how fast your computer
performs work.

35.  2. Accuracy: - The degree of accuracy of computer
is very high and every calculation is performed with
the same accuracy. The accuracy level is 7
 determined on the basis of design of computer. The
errors in computer are due to human and inaccurate
data

36.  3. Diligence: - A computer is free from tiredness,
lack of concentration, fatigue, etc. It can work for
hours without creating any error. If millions of
calculations are to be performed, a computer will
perform every calculation with the same accuracy.
Due to this capability it overpowers human being in
routine type of work.

37.  4. Versatility: - It means the capacity to perform
completely different type of work. You may use your
computer to prepare payroll slips. Next moment you
may use it for inventory management or to prepare
electric bills.

38.  5. Power of Remembering: - Computer has the
power of storing any amount of information or data.
Any information can be stored and recalled as long
as you require it, for any numbers of years. It
depends entirely upon you how much data you want
to store in a computer and when to lose or retrieve
these data.

39.  6. No IQ: - Computer is a dumb machine and it
cannot do any work without instruction from the
user. It performs the instructions at tremendous
speed and with accuracy. It is you to decide what you
want to do and in what sequence. So a computer
cannot take its own decision as you can.

40.  7. No Feeling: - It does not have feelings or
emotion, taste, knowledge and experience. Thus it
does not get tired even after long hours of work. It
does not distinguish between users.

41.  8. Storage: - The Computer has an in-
built memory where it can store a large amount of
data. You can also store data in secondary storage
devices such as floppies, which can be kept outside
your computer and can be carried to
other computers.

42. Hardware
42

43. 1. Keyboard,
2. Mouse,
3. Scanner
4. Microphone,
5. Digital Camera
6. Monitor,
7. Printer
8. Speaker,
9. Screen Image Projector
10. Hard Disc,
11. CD and DVD,
12. Pen drive
13. Touch Screen,
14. Personal Digital Assistants
15. Bar Code Readers,
16. LCD Projectors
17. Game Pads,
18. Joy Sticks
43

44.  Hardware represents the physical and tangible
components of a computer i.e. the components that
can be seen and touched.
 Examples of Hardware are following:
Input devices -- keyboard, mouse etc.
Output devices -- printer, monitor etc.
Secondary storage devices -- Hard disk, CD, DVD
etc.
Internal components -- CPU, motherboard, RAM
etc.
44

45. 45

46. 46

47. 47
What’s available for input…
 touch - fingers, feet, breath
 sound - voice, other sounds
 gesture
 gaze
 brainwaves…

48. 48
Input Devices
Used by a person to communicate to a computer.
Person to
computer

49. 49
and output…
 textual information
 visual images - photos, diagrams, icons
 moving images
 sounds - music, voice
 etc..

50. 50
Output Devices
Displays information from the computer to a person.

51. 51
Input Devices
 Keyboard
 Mouse
 Joy Stick
 Light pen
 Track Ball
 Scanner
 Graphic Tablet
 Microphone
 Bar Code Reader
 Optical Mark Reader(OMR)

52. 52
The Keyboard
THE MOST COMMONLY USED INPUT
DEVICE IS THE KEYBOARD ON
WHICH DATA IS ENTERED BY
MANUALLY KEYING IN OR TYPING
CERTAIN KEYS. A KEYBOARD
TYPICALLY HAS 101 OR 105 KEYS.

53. 53
Keyboard
 The keyboard allows the computer user to enter
words, numbers, punctuation, symbols, and
special function commands into the computer’s
memory.

54. Keyboard
 Keyboard is the most common and very popular
input device which helps in inputting data to the
computer. The layout of the keyboard is like that of
traditional typewriter, although there are some
additional keys provided for performing additional
functions.
 Keyboards are of two sizes 84 keys or 101/102 keys,
but now keyboards with 104 keys or 108 keys are
also available for Windows and Internet.
54

55. The keys on the keyboard
1. Typing Keys -These keys include the letter keys (A-Z) and digit keys
(0-9) which generally give same layout as that of typewriters.
2. Numeric Keypad It is used to enter numeric data or cursor
movement. Generally, it consists of a set of 17 keys that are laid out
in the same configuration used by most adding machines and
calculators.
3. Function Keys -The twelve function keys are present on the
keyboard which are arranged in a row at the top of the keyboard.
Each function key has unique meaning and is used for some
specific purpose.
4. Control keys -These keys provide cursor and screen control. It
includes four directional arrow keys. Control keys also include
Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl),
Alternate(Alt), Escape(Esc).
5. Special Purpose Keys -Keyboard also contains some special
purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar,
Tab, and Print Screen
55

56. 56
The Mouse
IS A POINTING DEVICE WHICH IS
USED TO CONTROL THE MOVEMENT
OF A MOUSE POINTER ON THE
SCREEN TO MAKE SELECTIONS
FROM THE SCREEN. A MOUSE HAS
ONE TO FIVE BUTTONS. THE
BOTTOM OF THE MOUSE IS FLAT
AND CONTAINS A MECHANISM
THAT DETECTS MOVEMENT OF THE
MOUSE.

57.  Mouse is most popular pointing device. It is a
very famous cursor-control device having a small
palm size box with a round ball at its base which
senses the movement of mouse and sends
corresponding signals to CPU when the mouse
buttons are pressed.
 Generally it has two buttons called left and right
button and a wheel is present between the
buttons. Mouse can be used to control the
position of cursor on screen, but it cannot be
used to enter text into the computer.
57

58. 58
Wheel
Mouse
Cordless
Mouse
Types of Mice
 Wheel mouse – Contains a rotating wheel
used to scroll vertically within a text document;
connects to PS/2 port or USB port
 Cordless mouse – Uses infrared signals to
connect to the computer’s IrDA port; it must be
within sight of the receiving port

59. Advantages
 Easy to use
 Not very expensive
 Moves the cursor faster than the arrow keys of
keyboard.
60

60. Joystick
 Joystick is also a pointing device which is used to
move cursor position on a monitor screen. It is a
stick having a spherical ball at its both lower and
upper ends. The lower spherical ball moves in a
socket. The joystick can be moved in all four
directions.
 The function of joystick is similar to that of a
mouse. It is mainly used in Computer Aided
Designing(CAD) and playing computer games.
61

61. 62
Pointing devices - direct
 Touch screens

62. 63
Touch screens
 Often used for applications with occasional
use, for example
 Bank ATMs, Information Kiosks, etc.
 No extra hardware - used for input and for
output
 Can be precise to 1 pixel
 Good for menu choice - not so good for other
functions
 Intuitive to use

63. 64
Touch screens
 BUT
 Tiring if at wrong angle (needs to be 30-45% from
horizontal)
 Get greasy, jammy
 Finger can obscure screen
 Alternative - use stylus to touch screen, or lightpen

64. 65
Indirect Pointing Devices
 Need more cognitive processing than direct
methods, but can be more efficient
 mouse
 tracker ball
 track point
 touchpad…

65. 66
Indirect pointing
devices - other
 Tracker ball, trackpad,
trackpoint
 Less space on desktop
 Good in moving
environments, e.g. car,
train

66. 67
Indirect pointing devices - other
 Joystick
 The main use of a joystick is to
play computer games by
controlling the way that
something moves on the screen.

67. 68
Microphones - Speech Recognition
•Use a microphone to talk to your
computer
•Add a sound card to your computer
•Sound card digitizes audio input
into 0/1s
•A speech recognition program can
process the input and convert it into
machine-recognized commands or
input

68. Microphone
 Microphone is an input device to input sound that is
then stored in digital form. The microphone is used
for various applications like adding sound to a
multimedia presentation or for mixing music.
69

69. 70
Audio Input: Speech Recognition
 Speech recognition is a
type of input in which the
computer recognizes words
spoken into a microphone.
 Special software and a
microphone are required.
 Latest technology uses
continuous speech
recognition where the user
does not have to pause
between words.

70. 71
Microphones - Speech Recognition

71. 72
Digital camera
A digital camera can store many more pictures
than an ordinary camera. Pictures taken using a
digital camera are stored inside its memory and can
be transferred to a computer by connecting the
camera to it. A digital camera takes pictures by
converting the light passing through the lens at the
front into a digital image.

72. 73
Scanner
A scanner can be used to input pictures and text into
a computer. There are two main types of scanner;
Hand-held and Flat-bed.

73. 74
Light pen
•A light pen is a small ‘pen-shaped’ wand, which
contains light sensors.
•It is used to choose objects or commands on the
screen either by pressing it against the surface of
the screen or by pressing a small switch on its side.
•A signal is sent to the computer, which then works
out the light pen’s exact location on the screen.
•The advantage of a light pen is that it doesn’t need
a special screen or screen coating.

74. Bar Code Readers
 Bar Code Reader is a device used for reading bar
coded data (data in form of light and dark lines). Bar
coded data is generally used in labelling goods,
numbering the books etc. It may be a hand held
scanner or may be embedded in a stationary scanner.
Bar Code Reader scans a bar code image, converts it
into an alphanumeric value which is then fed to the
computer to which bar code reader is connected.
75

75. 76
Bar codes
•A bar code is a set of lines of different thicknesses that
represent a number
•Bar Code Readers are used to input data from bar codes.
Most products in shops have bar codes on them
•Bar code readers work by shining a beam of light on the
lines that make up the bar code and detecting the amount
of light that is reflected back

76. 78
Output Types
 Text output
 Graphics output
 Video output
 Audio output

77. 79
Output Devices: Engaging our Senses
 Output devices are peripheral devices that enable us to
view or hear the computer’s processed data.
 Visual output – Text, graphics, and video
 Audio output – Sounds, music, and synthesized
speech

78. 80
Output Devices
 Monitors
 Printers
 Speakers
 Data Projectors

79. 81
Monitors
 A monitor is a peripheral device which displays
computer output on a screen.
 Screen output is referred to as soft copy.
 Types of monitors:
 Cathode-ray tube (CRT)
 Liquid Crystal Display (LCD or flat-panel)
CRT LCD

80. 82
Monitors
 CRT - Cathode Ray Tube
 electron gun shoots a stream of electrons at a specially
phosphor-coated screen
 on impact, the phosphor flares up for a fraction of a second
 electron gun sweeps across the screen many times a second
 LCD
 Liquid Crystal Display
 one of several types of “flat-panel” displays
 forms output by solidifying crystals and “backlighting” the
image with a light source
 TV sets are CRTs and many desktop monitors use this
technology
 LCD is primarily used for laptops and other portable
devices

81. Video Display Terminology
 Pixel
 picture element (smallest
unit of an image, basically a
single dot on the screen)
 Resolution
 number of pixels in the
image
 Common resolution size is
1024x768
 Refresh rate
 how often a CRT’s electron
gun rescans
 LCD displays do not use an
electron gun, so do not
perform refreshing
83
The CRT electron gun “shoots” 3
electrons at the screen
representing the amount of red,
green and blue for the pixel.

82. 84
Printers
 Ink Jet Printer
 least expensive, color, slower with a higher per page cost
than laser printers
 Laser Printer
 More expensive, faster, lower per page cost than ink jet,

83. 85
Printers
 A printer is a peripheral
device that produces a
physical copy or hard
copy of the computer’s
output.

84.  A printer is an output device that prints
characters, symbols, and perhaps graphics on
paper. The printed output is generally referred to
as hardcopy because it is in relatively
permanent form. Softcopy refers to temporary
images such as those displayed on a monitor.
Printers are categorized according to whether or
not the image produced is formed by physical
contact of the print mechanism with the paper.
Impact printers have contact; nonimpact printers
do not.
86

85. Impact Printers
 Impact printers operate by having an element strike the paper. In a
dot-matrix impact printer, which is the most common type still sold
as of October of 2012, the printer's print head has a vertical column
of pins which fire in order to generate characters.
 For instance, to make a capital "I" in a serif font, the top and bottom
pin would fire, then every pin would fire, then the top and bottom
pin would fire. The pins strike an ink-impregnated ribbon and press
it into the paper, leaving a mark. One of the problems with dot
matrix printing technology is that there are gaps between the pins,
leading to output that has a number of gaps and looks incomplete.
 Daisy wheel impact printers pressed a wheel with pre-formed
characters, much like the mechanism in an electrical typewriter,
against a ribbon to form an impression on a page. They produced
very high quality output but could only print in a single font and
character size. In addition, they were extremely slow, with some
printing just 10 characters per second.
87

86. Non-Impact Printers
 The print heads of non-impact printers do not strike
the page. In an inkjet printer, a print head sits a
small distance above the page and either sprays ink
or pops a bubble of ink onto the paper. Laser and
light-emitting diode printers use electrical charges to
transfer dry toner particles from a light sensitive
drum to a piece of paper and then melt the toner
onto it.
88

87. 89
Inkjet Laser
Types of Printers
 Inkjet printer, also
called a bubble-jet, makes
characters by inserting
dots of ink onto paper
 Letter-quality printouts
 Cost of printer is
inexpensive but ink is
costly
 Laser printer works like
a copier
 Quality determined by
dots per inch (dpi)
produced
 Color printers available
 Expensive initial costs but
cheaper to operate per
page

88. 90
Plotter
 A plotter is a printer that uses a pen that moves
over a large revolving sheet of paper.
 It is used in engineering, drafting, map making,
and seismology.

89. 91
Audio Output: Sound Cards and
Speakers
 Audio output is the ability of the computer to
output sound.
 Two components are needed:
 Sound card – Plays contents of digitized recordings
 Speakers – Attach to sound card

90. Hard Disc
 A hard disk drive (HDD), hard disk, hard drive or fixed disk is
a data storage device used for storing and retrieving digital information
using one or more rigid rapidly rotating disks (platters) coated with
magnetic material. The platters are paired with magnetic heads arranged
on a moving actuator arm, which read and write data to the platter
surfaces. Data is accessed in a random-access manner, meaning that
individual blocks of data can be stored or retrieved in any order and not
only sequentially. HDDs are a type of non-volatile memory, retaining
stored data even when powered off.
 Introduced by IBM in 1956, HDDs became the dominant secondary
storage device for general-purpose computers by the early 1960s.
Continuously improved, HDDs have maintained this position into the
modern era of servers and personal computers.
92

91. 93

92. CD
 Compact disc (CD) is a digital optical disc data
storage format, co-developed by Philips and Sony. The
format was originally developed to store and play only
sound recordings but was later adapted for storage of data
(CD-ROM). Several other formats were further derived from
these, including write-once audio and data storage (CD-R),
rewritable media (CD-RW), Video Compact Disc (VCD),
Super Video Compact Disc (SVCD), Photo CD,
PictureCD, CD-i, andEnhanced Music CD. Audio CD players
have been commercially available since October 1982,
when the first commercially available CD player was
released in Japan.
94

93. DVD
 DVD ("digital versatile disc” or "digital video
disc") is a digital optical disc storage format
invented and co-developed
by Sony, Philips, Toshiba, and Panasonic in 1995.
The medium can store any kind of digital data and
is widely used for software and other computer
files as well as video programs watched using DVD
players. DVDs offer higher storage capacity
than compact discs while having the same
dimensions.
95

94. 96

95. Pendrive
 A USB flash drive, also variously known as a USB drive, USB
stick, thumb drive, pen drive, flash-disk, or USB memory, is
a data storage device that includes flash memory with an
integrated USB interface. USB flash drives are typically
removable and rewritable, and physically much smaller than
an optical disc. Most weigh less than 30 grams
 USB flash drives are often used for the same purposes for
which floppy disks or CDs were once used, i.e., for storage,
data back-up and transfer of computer files. They are
smaller, faster, have thousands of times more capacity, and
are more durable and reliable because they have no moving
parts. Additionally, they are immune to electromagnetic
interference (unlike floppy disks), and are unharmed by
surface scratches (unlike CDs).
97

96. Pendrive
98

97. Touch Screen
 A touchscreen is an important source of input
device and output device normally layered on the top of
an electronic visual display of an information processing
system. A user can give input or control the information
processing system through simple or multi-touch
gestures by touching the screen with a special stylus and/or
one or more fingers.[1] Some touchscreens use ordinary or
specially coated gloves to work while others use a special
stylus/pen only. The user can use the touchscreen to react
to what is displayed and to control how it is displayed; for
example, zooming to increase the text size.
99

98.  The touch screen enables the user to interact directly with
what is displayed, rather than using a mouse, touchpad,
or any other intermediate device (other than a stylus,
which is optional for most modern touch screens).
 Touch screens are common in devices such as game
consoles, personal computers, tablet
computers, electronic voting machines, and smart
phones. They can also be attached to computers or, as
terminals, to networks. They also play a prominent role
in the design of digital appliances such as personal digital
assistants (PDAs) and some e-readers.
100

99.  The popularity of smartphones, tablets, and
many types of information appliances is driving
the demand and acceptance of common
touchscreens for portable and functional
electronics. Touchscreens are found in the
medical field and in heavy industry, as well as
for automated teller machines (ATMs), and
kiosks such as museum displays or room
automation, where keyboard and mouse systems
do not allow a suitably intuitive, rapid, or
accurate interaction by the user with the display's
content.
101

100. Personal Digital Assistants
 A personal digital assistant (PDA), also known as
a handheld PC, or personal data assistant, is amobile
device that functions as a personal information manager.
The term evolved from Personal Desktop Assistant, a
software term for an application that prompts or prods the
user of a computer with suggestions or provides quick
reference to contacts and other lists. PDAs were largely
discontinued in the early 2010s after the widespread
adoption of highly capable smartphones, in particular those
based on iOS and Android.
102

101. PDA
103

102. LCD Projectors
 An LCD projector is a type of video projector for displaying video,
images or computer data on a screen or other flat surface. It is a modern
equivalent of the slide projector or overhead projector. To display
images, LCD (liquid-crystal display) projectors typically send light from
a metal-halide lamp through a prism or series of dichroic filters that
separates light to three poly silicon panels – one each for the red, green
and blue components of the video signal. As polarized light passes
through the panels (combination of polarizer, LCD panel and analyzer),
individual pixels can be opened to allow light to pass or closed to block
the light. The combination of open and closed pixels can produce a wide
range of colours and shades in the projected image.
 Metal-halide lamps are used because they output an ideal colour
temperature and a broad spectrum of colour. These lamps also have the
ability to produce an extremely large amount of light within a small
area; current projectors average about 2,000 to 15,000 American
National Standards Institute (ANSI) lumens.
104

103. 105

104. Game Pads,
 A gamepad (also called joypad), is a type
of game controller held in two hands, where the
fingers (especially thumbs) are used to provide
input. They are typically the main method of input
for video game consoles.
 Gamepads generally feature a set
of buttons handled with the right thumb and a
direction controller handled with the left.
The direction controller has traditionally been a
four-way digital cross
106

105. 107

106. Screen Image Projector
 A projector or image projector is
an optical device that projects an image (or moving
images) onto a surface, commonly a projection
screen.
 Most projectors create an image by shining a light
through a small transparent lens, but some newer
types of projectors can project the image directly,
by using lasers. A virtual retinal display, or retinal
projector, is a projector that projects an image
directly on the retina instead of using an external
projection screen.
108

107. 109

108. Mother Board
 The motherboard is a sheet of plastic that holds all the
circuitry to connect the various components of a computer
system.
 A motherboard is one of the most essential parts of a
computer system. It holds together many of the crucial
components of a computer, including the central processing
unit (CPU), memory and connectors for input and output
devices. The base of a motherboard consists of a very firm
sheet of non-conductive material, typically some sort of rigid
plastic. Thin layers of copper or alluminum foil, referred to
as traces, are printed onto this sheet. These traces are very
narrow and form the circuits between the various
components. In addition to circuits, a motherboard contains
a number of sockets and slots to connect the other
110

109. 111

110. 112
Summary
• Introduction to Hardware
• Input Devices
– Keyboard,mouse,joystick,scanners,digital camera,
bar code reader, touch Sreeen,Speech input device
(microphone)
• Output Devices
– Monitor , Speaker, Printers ( different types)

111. Relationship between Hardware and Software
 Hardware and software are mutually dependent on each other. Both of
them must work together to make a computer produce a useful output.
 Software cannot be utilized without supporting hardware.
 Hardware without set of programs to operate upon cannot be utilized
and is useless.
 To get a particular job done on the computer, relevant software should
be loaded into the hardware
 Hardware is a one-time expense.
 Software development is very expensive and is a continuing expense.
 Different software applications can be loaded on a hardware to run
different jobs.
 A software acts as an interface between the user and the hardware.
 If hardware is the 'heart' of a computer system, then software is its
'soul'. Both are complimentary to each other.
113

112. Introduction to Computer
Software

113. Syllabus-
 Concept and Functions of Operating System
 Application Software –
 Word Processor,
 Presentation Software
 Data Management,
 Spreadsheet, Content Access Software- Media Player
 Application Software – Media Development
Software- Image Editing Software

114.  An operating system (OS) is system software that manages computer
hardware and software resources and provides
common services for computer programs. All computer programs,
excluding firmware, require an operating system to function.
 Time-sharing operating systems schedule tasks for efficient use of the
system and may also include accounting software for cost allocation of
processor time, mass storage, printing, and other resources.
 For hardware functions such as input and output and memory
allocation, the operating system acts as an intermediary between
programs and the computer hardware,[1][2] although the application code
is usually executed directly by the hardware and frequently
makes system calls to an OS function or is interrupted by it. Operating
systems are found on many devices that contain a computer –
from cellular phones and video game consoles to web servers and
supercomputers.

115. Software & Hardware?
 Computer Instructions or data, anything that can be stored
electronically is Software.
 Software means computer instructions or data. Anything
that can be stored electronically is software
 Hardware is one that is tangible. The storage devices (Hard
disk, CD’s etc.,), mouse, keyboard CPU and display devices
(Monitor) are Hardware.
For example: There is a problem in the Software implies –
Problem with program or data

116. Types of Software
 Organized information in the form of operating systems,
utilities, programs, and applications that enable computers
to work.
 Software consists of carefully-organized instructions and
code written by programmers in any of various special
computer languages. Software is divided commonly into 4
main categories:
• System Software
• Application Software
• Open source Software
• Proprietary Software

118. System Software:
System Software includes the Operating System and all
the utilities that enable the computer to function.
System software is a term referring to any computer
software which manages and controls the hardware so
that application software can perform a task.
System software: controls the basic (and invisible to the
user) functions of a computer and comes usually
preinstalled with the machine. See also BIOS and
Operating System.
Example:
Operating Systems, Compiler, Loader, Linker,
Interpreter.

119. System Software
Operating System:
 Operating System is a software, which makes a computer
to actually work.
 It is the software the enables all the programs we use.
 The OS organizes and controls the hardware.
 OS acts as an interface between the application programs
and the machine hardware.
 Examples: Windows, Linux, Unix and Mac OS, etc.,

120. System Software
Loader: A loader is the part of an operating system that is
responsible for loading programs into memory, preparing
them for execution and then executing them.
The loader is usually a part of the operating system's kernel
and usually is loaded at system boot time and stays in
memory until the system is rebooted, shut down, or
powered off.
In Unix, the loader is the handler for the system call
execve().

121. System Software
Interpreter: An interpreter is a computer
program that translates and executes
instructions written in a computer programming
language line-by-line, unit by unit etc.,
An interpreter needs to be able to analyze, or
parse, instructions written in the source
language.
Example: Lisp systems, etc.,

122. System Software
Source
Languages
Target Languages
‘C’ language ‘C’ language
‘Pascal’ language Machine language
FORTRAN language
C++ language
ADA language
Compiler: A compiler is a program that reads a program
in one language – the source language and translates into
an equivalent program in another language – the target
language.

123. System Software (contd):
Linker: A linker or link editor is a program that takes
one or more objects generated by compilers and assembles
them into a single executable program.
Linkers can take objects from a collection called a library.
The objects are program modules containing machine code
and information for the linker.
The linker takes care of arranging the objects in a
program's address space.

124. Application Software:
Word Processors:
Word processing is a tool that helps user in creating,
editing, and printing documents. Word processors will
normally have the following capabilities built into them:
• Spell checking
• Standard layouts for normal documents
• Have some characters appear in bold print,
italics, or underlined
• Center lines, make text line up on the left side of
the paper, or the right side of the paper
• Save the document so it can be used again
• print the document.
Examples: WordPerfect and Microsoft Word

125. Application Software
Spreadsheets: The spreadsheet packages are
designed to use numbers and formulas to do calculations
with ease. Examples of spreadsheets include:
• Budgets
• Payrolls
• Grade Calculations
• Address Lists
The most commonly used spreadsheet programs are
Microsoft Excel and Lotus 123.

126. Application Software
Graphic Presentations: The presentation
programs can make giving presentations and using
overheads easier. Other uses include:
• Slide Shows
• Repeating Computer Presentations on a computer
monitor
• Using Sound and animation in slide shows
The most recognized graphic presentation programs are
Microsoft PowerPoint and Harvard Graphics.

127. Application Software
Database Management System (DBMS):
 A DBMS is a software tool that allows multiple users to
store, access, and process data into useful information.
 Database programs are designed for these types of
applications:
• Membership lists
• Student lists
• Grade reports
• Instructor schedules
All of these have to be maintained so you can find what you
need quickly and accurately.
 Example:Microsoft Access, dBASE, Oracle.

128. Functions of Application Software
 The function of application software is to perform
specific operations for various applications.
 These functions include writing reports, creating
spreadsheets, manipulating images, keeping records,
developing websites and calculating expenses.

129. Open Source Software:
 Open source software (OSS) is computer software
whose source code is available under a license that permits
users to use, change, and improve the software, and to
redistribute it in modified or unmodified form.
 It is often developed in a public, collaborative manner.
Well-known OSS products are Linux, Netscape, Apache,
etc.,

130. Proprietary Software
 Proprietary software (also called non-free
software) is software with restrictions on using,
copying and modifying as enforced by the proprietor.
Restrictions on use, modification and copying is
achieved by either legal or technical means and
sometimes both.
 Proponents of proprietary software are Microsoft.
 Ex: CAD, Nortan Antivirus etc.,

131. 133
THANK YOU