1. 1
What is aWhat is a
Computer?Computer?

2. 2
ComputerComputer
An electronic device whichAn electronic device which
manipulates and stores datamanipulates and stores data
It performs mathematicalIt performs mathematical
and logical operationsand logical operations

3. 3
Parts of aParts of a
ComputerComputer

4. 4

5. 5
SystemSystem
 Any collection of componentAny collection of component
elements that work together toelements that work together to
perform a task.perform a task.

6. 6
E-Data ProcessingE-Data Processing
Hardware
Software
Peopleware

7. 7
Computer SystemComputer System
 A complete, working computerA complete, working computer
 The computer system includes notThe computer system includes not
only the computer itself (hardware),only the computer itself (hardware),
but also any software and data that arebut also any software and data that are
necessary to make the computernecessary to make the computer
function.function.
 Likewise, human intervention is alsoLikewise, human intervention is also
neededneeded

8. 8
Components ofComponents of
Computer SystemComputer System

9. 9
HardwareHardware
Tangible parts of the computerTangible parts of the computer
systemsystem
It includes all the physical partsIt includes all the physical parts
such as CPU, Monitor,such as CPU, Monitor,
keyboard and etc.keyboard and etc.

10. 10
Computer HardwareComputer Hardware

11. 11
Input DevicesInput Devices
- These are devices used to enter- These are devices used to enter
information into a computerinformation into a computer

12. 12
KeyboardKeyboard
 One of the most used input devices,One of the most used input devices,
consisting of keys which are pressed toconsisting of keys which are pressed to
enter data and instructions into theenter data and instructions into the
computercomputer
 IBM first introduced the 83-key keyboardIBM first introduced the 83-key keyboard
followed by the 84 keys and finally 101-keyfollowed by the 84 keys and finally 101-key
keyboard which was the de facto standard,keyboard which was the de facto standard,
until further modifications were introduceduntil further modifications were introduced
by Microsoft.by Microsoft.

13. 13
QWERTY Keyboard LayoutQWERTY Keyboard Layout
 Originally designed by ChristopherOriginally designed by Christopher
Sholes in 1867Sholes in 1867
 Its name was derived from the first sixIts name was derived from the first six
characters on the top row of normalcharacters on the top row of normal
keyboard arrangement.keyboard arrangement.

14. 14
KeyboardKeyboard

15. 15
MouseMouse
 It is used to move on and control aIt is used to move on and control a
pointer on the computer screen,pointer on the computer screen,
specifically in a graphical user interfacespecifically in a graphical user interface
(GUI) system(GUI) system
 This is connected to the computer byThis is connected to the computer by
wire/ wireless and is held by handwire/ wireless and is held by hand

16. 16
MouseMouse

17. 17
TrackballTrackball
 It is similar to the mouseIt is similar to the mouse
 It also has a rotating ball, but the ball isIt also has a rotating ball, but the ball is
on top. Instead of moving the deviceon top. Instead of moving the device
itself, the user moves the ballitself, the user moves the ball

18. 18
JoystickJoystick
 This gives the computer informationThis gives the computer information
on the direction and extent ofon the direction and extent of
displacement of a hand-held lever,displacement of a hand-held lever,
enabling a corresponding movement inenabling a corresponding movement in
an object on the screen that is part ofan object on the screen that is part of
particular programparticular program
 Usually used for games.Usually used for games.

19. 19
Light PenLight Pen
 It is shaped like a pen with the telltaleIt is shaped like a pen with the telltale
cable connecting it to the computercable connecting it to the computer
 This is used to indicate a particularThis is used to indicate a particular
location on a a computer screen and islocation on a a computer screen and is
usually utilized for programs onusually utilized for programs on
computer-aided design (CAD)computer-aided design (CAD)

20. 20
ScannerScanner
 This device inputs a digital imageThis device inputs a digital image
of a document or picture into aof a document or picture into a
computer.computer.
 This is usually consists of a flatThis is usually consists of a flat
bed, on which an image is placedbed, on which an image is placed
and scannedand scanned

21. 21
Graphics TabletGraphics Tablet
 This is an input device in which aThis is an input device in which a
stylus is moved, by hand, over a flatstylus is moved, by hand, over a flat
surfacesurface
 The position of the stylus is tracked soThe position of the stylus is tracked so
that the user can input shapes andthat the user can input shapes and
drawingsdrawings

22. 22
Touch-Sensitive ScreenTouch-Sensitive Screen
 This is a computer monitor, whichThis is a computer monitor, which
consists of a specialized screenconsists of a specialized screen
 Users can touch particular areas orUsers can touch particular areas or
touch-points on the screen to inputtouch-points on the screen to input
certain preferences or commandscertain preferences or commands

23. 23
Recognition DevicesRecognition Devices
 These devices are mostly used byThese devices are mostly used by
banks and commercial establishmentsbanks and commercial establishments
to recognize and input large volumesto recognize and input large volumes
of dataof data
 These include Optical CharacterThese include Optical Character
Recognition (OCR), Optical MarkRecognition (OCR), Optical Mark
Recognition (OMR)Recognition (OMR)

24. 24
Voice RecognitionVoice Recognition
DeviceDevice
 Allow you to communicate to theAllow you to communicate to the
computer through speech and the likecomputer through speech and the like
 The simplest example is a condenserThe simplest example is a condenser
microphone which can be used tomicrophone which can be used to
capture soundcapture sound

25. 25
Processing DeviceProcessing Device
- Device used to process data- Device used to process data
into informationinto information

26. 26
CCentralentral PProcessingrocessing UUnitnit
 The main part of a computer whichThe main part of a computer which
executes instructions and controlsexecutes instructions and controls
various other functions of thevarious other functions of the
computercomputer
 It consists of Arithmetic and LogicIt consists of Arithmetic and Logic
Unit (ALU), Control Unit and theUnit (ALU), Control Unit and the
MemoryMemory

27. 27
Microprocessor / CPUMicroprocessor / CPU

28. 28
System UnitSystem Unit
It contains the centralIt contains the central
processing unit and primaryprocessing unit and primary
memory (the electronic circuitrymemory (the electronic circuitry
that enables the computer tothat enables the computer to
process and store data)process and store data)

29. 29
System UnitSystem Unit

30. 30

31. 31
Power InputPower Input
Where your plug in the PC’sWhere your plug in the PC’s
electrical power cordelectrical power cord

32. 32
Keyboard PortKeyboard Port
Dedicated port for theDedicated port for the
keyboardkeyboard

33. 33
Mouse PortMouse Port
Dedicated port for theDedicated port for the
mousemouse

34. 34
USB PortsUSB Ports
Universal Serial Bus portsUniversal Serial Bus ports
are general-purposeare general-purpose
connectors found on newerconnectors found on newer
PCs.PCs.

35. 35
Serial PortsSerial Ports
This-9 pin connector is oneThis-9 pin connector is one
of the oldest and mostof the oldest and most
universal ports found in theuniversal ports found in the
back of the PC.back of the PC.

36. 36
Parallel PortParallel Port
Virtually as old as the serialVirtually as old as the serial
port, the 25-pin parallel portport, the 25-pin parallel port
has been updated a numberhas been updated a number
of times, popular means forof times, popular means for
connecting printersconnecting printers

37. 37
Video PortVideo Port
This unique three-row, 15-This unique three-row, 15-
pin connector is where thepin connector is where the
monitor connects to themonitor connects to the
system unitsystem unit

38. 38
Audio PortsAudio Ports
Used to connect speakers,Used to connect speakers,
microphones, and othermicrophones, and other
audio devicesaudio devices

39. 39
Game PortGame Port
Also known as a joystickAlso known as a joystick
port, this 15-pin connectorport, this 15-pin connector
can be used for both joystickcan be used for both joystick
and for MIDI musicaland for MIDI musical
devicesdevices

40. 40
Modem PortModem Port
This looks like a telephoneThis looks like a telephone
jack.jack.
It enables your computer toIt enables your computer to
communicate with othercommunicate with other
computer via telephone line.computer via telephone line.

41. 41
Network InterfaceNetwork Interface
It sometimes referred to asIt sometimes referred to as
an Ethernet connector.an Ethernet connector.
It connects your PC to otherIt connects your PC to other
PCs in a Local AreaPCs in a Local Area
NetworkNetwork

42. Proper Opening andProper Opening and
Shutting Down of aShutting Down of a
ComputerComputer
42

43. Opening of a ComputerOpening of a Computer
1.1. Check all the cables if properly connectedCheck all the cables if properly connected
2.2. Plug and switch on the AVRPlug and switch on the AVR
3.3. Switch on the MonitorSwitch on the Monitor
4.4. Press the Power Button of the System UnitPress the Power Button of the System Unit
5.5. Wait until the desktop appears and the cursorWait until the desktop appears and the cursor
will look like thiswill look like this  before opening anybefore opening any
programprogram
43

44. Shutting Down of a ComputerShutting Down of a Computer
 Close all the programsClose all the programs
 Click the Start button and click Turn Off orClick the Start button and click Turn Off or
Shut DownShut Down
 A dialog box will appear, click again the TurnA dialog box will appear, click again the Turn
Off or Shut Down buttonOff or Shut Down button
 Wait until the monitor turns off or totally blackWait until the monitor turns off or totally black
screen.screen.
 Switch Off the monitorSwitch Off the monitor
 Switch off and unplug the AVRSwitch off and unplug the AVR 44

45. 45
InternalInternal
Components ofComponents of
a System Unita System Unit

46. 46

47. 47
CPUCPU
 Central Processing UnitCentral Processing Unit
 The brain of the computerThe brain of the computer
 AMD (Advanced Microdevices)AMD (Advanced Microdevices)
and Intel Corporationand Intel Corporation

48. 48
Random Access MemoryRandom Access Memory
(RAM)(RAM)
 The CPU’s short-termThe CPU’s short-term
memory.memory.
 Volatile storageVolatile storage
 Can be accessed quickly but itCan be accessed quickly but it
disappears when the power isdisappears when the power is
turned off.turned off.

49. 49
Memory DevicesMemory Devices
 These are devices that are used for theThese are devices that are used for the
temporary and short-term storage oftemporary and short-term storage of
data, which the compute can usedata, which the compute can use
during processingduring processing
 These include ROM (Read OnlyThese include ROM (Read Only
Memory) and (RAM) Random AccessMemory) and (RAM) Random Access
MemoryMemory

50. 50
Random Access MemoryRandom Access Memory

51. 51
NorthbridgeNorthbridge
 A special helper chip thatA special helper chip that
connects CPU and RAMconnects CPU and RAM
 BUS – multiple wires used toBUS – multiple wires used to
connect two or more devices inconnect two or more devices in
the motherboard.the motherboard.
 Frontside Bus – connects theFrontside Bus – connects the
CPU, Northbridge and RAMCPU, Northbridge and RAM

52. 52
CPU SpeedsCPU Speeds
 Clock Chip – a crystal thatClock Chip – a crystal that
oscillates at a certain frequencyoscillates at a certain frequency
when electricity us applied to it,when electricity us applied to it,
providing the system speed.providing the system speed.
 Each click of the clock isEach click of the clock is
measured in millions or billions ofmeasured in millions or billions of
cycles per secondcycles per second

53. 53
Note:Note:
 One cycle per second is HertzOne cycle per second is Hertz
(Hz)(Hz)
 One million cycles per secondOne million cycles per second
is a megahertz (MHz)is a megahertz (MHz)
 One billion cycles per secondOne billion cycles per second
is a gigahertz (GHz)is a gigahertz (GHz)

54. 54
Processor PackagesProcessor Packages
The form factor of the chip : itsThe form factor of the chip : its
shape, size and external featuresshape, size and external features

55. 55
Types ofTypes of
ProcessorProcessor
PackagePackage

56. 56
Single-Edge CartridgeSingle-Edge Cartridge
(SEC)(SEC)
Introduced in mid-1990sIntroduced in mid-1990s
Pentium II is an example of thisPentium II is an example of this
package.package.

57. 57
Pin-Grid Array (PGA)Pin-Grid Array (PGA)
 Most commonly used package forMost commonly used package for
the processorthe processor
 It has tiny golden wires sticking outIt has tiny golden wires sticking out
the underside of the CPUthe underside of the CPU

58. 58
MotherboardMotherboard
 The big printed circuit boardThe big printed circuit board
that covers most of the bottomthat covers most of the bottom
of the system unit.of the system unit.
 Provide an area where all ofProvide an area where all of
the internal components of thethe internal components of the
PC can connect.PC can connect.

59. 59
Expansion slotsExpansion slots
 Enable you to expand theEnable you to expand the
capabilities of your system bycapabilities of your system by
adding extra components.adding extra components.
 Any device that snaps into anAny device that snaps into an
expansion slot is an expansionexpansion slot is an expansion
card.card.

60. 60
Three Types ofThree Types of
ExpansionExpansion
SlotsSlots

61. 61
1. PCI1. PCI
Peripheral ComponentPeripheral Component
InterconnectInterconnect
Expansion slot used forExpansion slot used for
high-speed input/outputhigh-speed input/output
device which uses PCIdevice which uses PCI
busbus

62. 62
2. AGP2. AGP
Accelerated GraphicsAccelerated Graphics
PortPort
Expansion slot used forExpansion slot used for
a video carda video card

63. 63
3. ISA3. ISA
Industry StandardIndustry Standard
ArchitectureArchitecture
Used by older and/orUsed by older and/or
slower devicesslower devices

64. 64
Hard DriveHard Drive
The PC’s long-termThe PC’s long-term
memory; data storedmemory; data stored
there remains availablethere remains available
for later use.for later use.

65. 65
IDEIDE
Integrated Drive ElectronicsIntegrated Drive Electronics
A standard that defines howA standard that defines how
the motherboardthe motherboard
communicates withcommunicates with
secondary storage devices.secondary storage devices.

66. 66
CD-ROM DrivesCD-ROM Drives
Compact Disc – ReadCompact Disc – Read
Only MemoryOnly Memory
Design to read CDs.Design to read CDs.

67. 67
CD-RCD-R
Compact DiscCompact Disc
RecordableRecordable
Allow you to write data toAllow you to write data to
them but only one timethem but only one time

68. 68
CD-RWCD-RW
Compact DiscCompact Disc
ReWritableReWritable
Enables you to read andEnables you to read and
write repeatedly.write repeatedly.

69. 69
Floppy DrivesFloppy Drives
Read floppy discsRead floppy discs
The first kind of storageThe first kind of storage
used by PCsused by PCs

70. Data HierarchyData Hierarchy
 Bit = 1 or 0Bit = 1 or 0
 1 Byte = 8 bits = 1 character1 Byte = 8 bits = 1 character
 1024 Bytes = 1 Kilobyte1024 Bytes = 1 Kilobyte
 1024 KB = 1 Megabyte1024 KB = 1 Megabyte
 1024 MB = 1 Gigabyte1024 MB = 1 Gigabyte
 1024 G = 1 Terabyte1024 G = 1 Terabyte
70

71. 71
Video CardVideo Card
Also known as graphicAlso known as graphic
adapteradapter
Act as the interfaceAct as the interface
between computer andbetween computer and
monitormonitor

72. 72
Power SupplyPower Supply
Converts standardConverts standard
household A/C currenthousehold A/C current
into the D/C currentinto the D/C current
needed by the PCneeded by the PC

73. 73
Sound CardSound Card
Provides the sound inputProvides the sound input
and output for your PC.and output for your PC.
Used for speakers andUsed for speakers and
microphonesmicrophones

74. 74
Network Interface CardNetwork Interface Card
(NIC)(NIC)
To access a Local AreaTo access a Local Area
NetworkNetwork

75. 75
Output DevicesOutput Devices
-Display or transfer-Display or transfer
information to the user afterinformation to the user after
processingprocessing

76. 76
MonitorMonitor
 One of the most common output devices.One of the most common output devices.
It is the screen which shows the results ofIt is the screen which shows the results of
processing or the inputs of the userprocessing or the inputs of the user
 Desktop or Personal Computers comeDesktop or Personal Computers come
with Cathode-Ray Tube(CRT) similar towith Cathode-Ray Tube(CRT) similar to
those of televisions while Laptopthose of televisions while Laptop
computers come with a Liquid Crystalcomputers come with a Liquid Crystal
Display(LCD).Display(LCD).

77. 77
MonitorMonitor

78. 78
PrinterPrinter
 This device provides hardcopy or aThis device provides hardcopy or a
printout to the userprintout to the user
 It takes text as inputted and thenIt takes text as inputted and then
prints them on paperprints them on paper

79. 79
Types of PrinterTypes of Printer
 Dot Matrix – use small wires to press onDot Matrix – use small wires to press on
ribbons and quite noisyribbons and quite noisy
 Inkjet Printer – similar to matrix printersInkjet Printer – similar to matrix printers
but instead of using needles it spraysbut instead of using needles it sprays
droplets of ink onto the paper to formdroplets of ink onto the paper to form
imagesimages
 Laser Printer – noise-free, as these employLaser Printer – noise-free, as these employ
light to draw text and images; useslight to draw text and images; uses
electrostatic processelectrostatic process

80. 80
PlotterPlotter
 It is a special output device which alsoIt is a special output device which also
causes printed output to be producedcauses printed output to be produced
in a manner not too different fromin a manner not too different from
that used by regular printersthat used by regular printers

81. 81
SpeakersSpeakers
 Provide output for voice, sound orProvide output for voice, sound or
music and are a necessary of amusic and are a necessary of a
multimedia systemmultimedia system

82. 82
Storage Media &Storage Media &
DevicesDevices
- Provide a permanent storage- Provide a permanent storage
for data, information andfor data, information and
programs for later use orprograms for later use or
retrievalretrieval

83. 83
Hard DiskHard Disk
 Most common storage media whichMost common storage media which
usually permanent part of theusually permanent part of the
computercomputer
 This is where most programs and dataThis is where most programs and data
are stored, especially the operatingare stored, especially the operating
system for fast retrieval and executionsystem for fast retrieval and execution
by the userby the user

84. 84
Floppy DiskFloppy Disk
 This is removable storage device whichThis is removable storage device which
has a smaller capacity compared to ahas a smaller capacity compared to a
hard diskhard disk
 The standard 3.5-inch floppy disk hasThe standard 3.5-inch floppy disk has
1.44 MB capacity1.44 MB capacity

85. 85
Compact Disc (CD)Compact Disc (CD)
 Also a removable device with a largerAlso a removable device with a larger
capacity than a floppycapacity than a floppy
 It usually come in the form of CD-ROMIt usually come in the form of CD-ROM
(Compact Disc-Read Only Memory)(Compact Disc-Read Only Memory)
 The common capacity of a CD-ROM isThe common capacity of a CD-ROM is
650MB650MB
 There are also recordable and erasable CDsThere are also recordable and erasable CDs

86. 86
Digital Video Disc (DVD)Digital Video Disc (DVD)
 CDs which contain a very largeCDs which contain a very large
amount of data and are used foramount of data and are used for
storing films and other data-intensivestoring films and other data-intensive
files such as computer games andfiles such as computer games and
applicationsapplications
 Usually store up to 8 GB of dataUsually store up to 8 GB of data

87. 87
Hardware ConnectionHardware Connection
- These are the connectors that- These are the connectors that
physically connect and link thephysically connect and link the
components and devices socomponents and devices so
that they can interact andthat they can interact and
exchange dataexchange data

88. 88
BUSBUS
 This is a group of wires composing aThis is a group of wires composing a
system interconnections that allowsystem interconnections that allow
communication between the differentcommunication between the different
devicesdevices
 It is the electrical pathway throughIt is the electrical pathway through
which the computer processorwhich the computer processor
communicatescommunicates

89. 89
Circuit BoardsCircuit Boards
 These are arrangements of electricalThese are arrangements of electrical
components through which signals orcomponents through which signals or
current can pass throughcurrent can pass through

90. 90
Serial ConnectionSerial Connection
 This type of connection whichThis type of connection which
involves a slow transfer of informationinvolves a slow transfer of information
from the computer to an externalfrom the computer to an external
component such as mouse or printercomponent such as mouse or printer

91. 91
Parallel ConnectionParallel Connection
 Uses multiple sets of wires but isUses multiple sets of wires but is
limited in terms of distance coveredlimited in terms of distance covered
 It also connects components such asIt also connects components such as
printers or scanners to the computerprinters or scanners to the computer

92. 92
Types of SoftwareTypes of Software

93. 93
System SoftwareSystem Software
 The kind of software that controls andThe kind of software that controls and
takes care of the working computer andtakes care of the working computer and
overall functioning of the system.overall functioning of the system.
 The best example of system software is theThe best example of system software is the
operating systemoperating system
 Ex. Windows XP, Windows ME, WindowsEx. Windows XP, Windows ME, Windows
XP, Linux, Unix, Apple’s OSXP, Linux, Unix, Apple’s OS

94. 94
Application SoftwareApplication Software
 Software that generally suited toSoftware that generally suited to
perform a particular task or functionperform a particular task or function
 Ex. Word Processor, Spreadsheet,Ex. Word Processor, Spreadsheet,
Computer Games, Desktop PublishingComputer Games, Desktop Publishing
Software and Graphics ProgramSoftware and Graphics Program

95. 95
Types of ProductionTypes of Production
of Softwareof Software

96. 96
Commercial SoftwareCommercial Software
 These are created and marketed byThese are created and marketed by
big software companiesbig software companies
 Usually made by a team of expertsUsually made by a team of experts
and computer professionals andand computer professionals and
are sold for quite a big priceare sold for quite a big price
 Ex. Microsoft Windows OS, MSEx. Microsoft Windows OS, MS
OfficeOffice

97. 97
SharewareShareware
 Because of the high cost of software,Because of the high cost of software,
many individual programmers mademany individual programmers made
sharewareshareware
 Shareware, however is not reallyShareware, however is not really
shared but is lent or allowed to beshared but is lent or allowed to be
tested for a time before a fee istested for a time before a fee is
requestedrequested

98. 98
FreewareFreeware
 Given for free or allowed to beGiven for free or allowed to be
downloaded from the Internet.downloaded from the Internet.
 Programmers who create freeware doProgrammers who create freeware do
it as a service to users who cannotit as a service to users who cannot
afford programsafford programs

99. 99
Output DeviceOutput Device
 It displays data once it has beenIt displays data once it has been
processed.processed.
 The most common output devicesThe most common output devices
are the computerare the computer display screendisplay screen
andand printerprinter

100. 100
Secondary Storage DeviceSecondary Storage Device
 It allows data to be permanently storedIt allows data to be permanently stored
so that it can be used at a later time.so that it can be used at a later time.
 Common secondary storage devicesCommon secondary storage devices
include floppy disk drives, hard diskinclude floppy disk drives, hard disk
drives, and CD-ROM drivesdrives, and CD-ROM drives

101. 101
Note:Note:
Input, output and secondaryInput, output and secondary
storage devices are alsostorage devices are also
sometimes referred to assometimes referred to as
peripheral devicesperipheral devices

102. 102
SoftwareSoftware
 It is a set of instructions that tells theIt is a set of instructions that tells the
computer hardware what to do.computer hardware what to do.
 It is also known as programIt is also known as program
 Examples: MS Word, Excel, &Examples: MS Word, Excel, &
PowerPointPowerPoint

103. 103
PeoplewarePeopleware
 They are mainly responsible for theThey are mainly responsible for the
development and use of the systemdevelopment and use of the system
 No computer would run withoutNo computer would run without
the help of peoplethe help of people

104. 104
How theHow the
ComputerComputer
Works?Works?

105. 105
Electronic vs.Electronic vs.
ElectricElectric

106. 106
ComputerComputer
 It is an electronic deviceIt is an electronic device
 An electronic device uses very smallAn electronic device uses very small
electric current at very low voltageelectric current at very low voltage
levels to represent and store statelevels to represent and store state
informationinformation

107. 107
Electronic DeviceElectronic Device
 Generally, at 0 volt the state is off andGenerally, at 0 volt the state is off and
at 5 volts the state is on.at 5 volts the state is on.
 Power dissipation for computers,Power dissipation for computers,
particularly portable such as laptopsparticularly portable such as laptops
and palmtops is kept low.and palmtops is kept low.

108. 108
Electric ApplianceElectric Appliance
 It uses raw power to operate and functionIt uses raw power to operate and function
and not to store or represent dataand not to store or represent data
 Air-conditioning units, refrigerators,Air-conditioning units, refrigerators,
electric fans, and the like all use powerlineelectric fans, and the like all use powerline
voltage levels of 110 or 220 volts.voltage levels of 110 or 220 volts.

109. 109
Does it mean thatDoes it mean that
computers do notcomputers do not
require powerlinerequire powerline
electricity?electricity?

110. 110
 The answer is NO.The answer is NO.
 Computers use the 110- or 220-Computers use the 110- or 220-
volt electricity for their powervolt electricity for their power
supply and internally convert thissupply and internally convert this
to the appropriate voltage levels.to the appropriate voltage levels.

111. 111
Let us see howLet us see how
an on or an off isan on or an off is
used to representused to represent
data.data.

112. 112
Data HierarchyData Hierarchy

113. 113
BitBit
 Smallest unit of dataSmallest unit of data
 Represented by 0 or 1Represented by 0 or 1

114. 114
NibbleNibble
 It consists of four bitsIt consists of four bits

115. 115
ByteByte
 It consists of 8 bits or 1 characterIt consists of 8 bits or 1 character
 Character – smallest meaningfulCharacter – smallest meaningful
unit of dataunit of data

116. 116
Kilobyte (KB)Kilobyte (KB)
 It consists of 1024 bytesIt consists of 1024 bytes

117. 117
Megabyte (MB)Megabyte (MB)
 It consists of 1024 KBIt consists of 1024 KB

118. 118
Gigabyte (GB)Gigabyte (GB)
 It consists of 1024 MBIt consists of 1024 MB

119. 119
Terabyte (TB)Terabyte (TB)
 It consists of 1024 GBIt consists of 1024 GB

120. 120
Petabyte (PB)Petabyte (PB)
 It consists of 1024 TBIt consists of 1024 TB

121. 121
Exabyte (EB)Exabyte (EB)
 It consists of 1024 PBIt consists of 1024 PB

122. 122
Proper Care ofProper Care of
ComputersComputers

123. 123
Here are some ways:Here are some ways:
Place your computer in a dry,Place your computer in a dry,
clean and cool placeclean and cool place
Do not eat or drink whileDo not eat or drink while
working on your computerworking on your computer

124. 124
Here are some ways:Here are some ways:
 Clean your computer regularly.Clean your computer regularly.
Use dry cloth and a waxUse dry cloth and a wax
specially made for computers.specially made for computers.
 Cover your computer when not inCover your computer when not in
use so that dust will not gatheruse so that dust will not gather
on it.on it.

125. 125
continuation…continuation…
 When you are using aWhen you are using a
computer, handle its parts withcomputer, handle its parts with
care.care.
 Do not hit your computer whenDo not hit your computer when
there is something wrong withthere is something wrong with
it. Call somebody who isit. Call somebody who is
technically knowledgeable intechnically knowledgeable in
fixing the problem.fixing the problem.

126. 126
continuation…continuation…
 Run the shutdown programRun the shutdown program
before turning off ,yourbefore turning off ,your
computer. Failure to do socomputer. Failure to do so
many results in data loss.many results in data loss.
 Clean your mouse regularlyClean your mouse regularly
so that you will not haveso that you will not have
difficult rolling it over a mousedifficult rolling it over a mouse
pad.pad.

127. 127
continuation…continuation…
 Protect the data stored in yourProtect the data stored in your
storage media. Place yourstorage media. Place your
disks and CD-ROM in adisks and CD-ROM in a
protective case. Don’t bendprotective case. Don’t bend
your disks or put them nearyour disks or put them near
magnets. Magnets willmagnets. Magnets will
damage the data stored indamage the data stored in
your disks.your disks.

128. 128
ComputerComputer
Problems andProblems and
IssuesIssues

129. 129
Software BreakdownSoftware Breakdown

130. 130
Things to do when SoftwareThings to do when Software
Breakdown occursBreakdown occurs
 Turn the computer off and thenTurn the computer off and then
on again (cold booting), thenon again (cold booting), then
run the program againrun the program again

131. 131
Things to do when SoftwareThings to do when Software
Breakdown occursBreakdown occurs
 If the program continues toIf the program continues to
encounter difficulties, tryencounter difficulties, try
reinstalling it.reinstalling it.
 If the problem continues,If the problem continues,
contact your software vendorcontact your software vendor
or dealer and try replacing theor dealer and try replacing the
software.software.

132. 132
Note:Note:
 This problem may occurs dueThis problem may occurs due
to other problems such as ato other problems such as a
hard disk loaded with toohard disk loaded with too
many programs, viruses or justmany programs, viruses or just
simple incompatibility with thesimple incompatibility with the
hardware.hardware.

133. 133
Hard Disk CrashHard Disk Crash

134. 134
Hard Disk CrashHard Disk Crash
 One of the worst experiences for a new userOne of the worst experiences for a new user
 When you turn on the computerWhen you turn on the computer
and nothing happensand nothing happens
 You find out that all the contentsYou find out that all the contents
of your hard disk are totally erasedof your hard disk are totally erased
without recovering any filewithout recovering any file

135. 135
Things to do when HardThings to do when Hard
Disk Crash occursDisk Crash occurs
 Have your hard disk checked ifHave your hard disk checked if
there is hope for recoveringthere is hope for recovering
any important data or fileany important data or file

136. 136
Things to do when HardThings to do when Hard
Disk Crash occursDisk Crash occurs
 Have your hard diskHave your hard disk
reformatted and programs youreformatted and programs you
want to reinstalledwant to reinstalled
 The next time you use yourThe next time you use your
computer, have a BACKUP ofcomputer, have a BACKUP of
all your important files inall your important files in
another storage media.another storage media.

137. 137
Virus AttacksVirus Attacks

138. 138
Virus AttacksVirus Attacks
Hard disk may crash causedHard disk may crash caused
by virusesby viruses
Computer may behave in anComputer may behave in an
unpredictable mannerunpredictable manner
The software or programsThe software or programs
may breakdownmay breakdown

139. 139
Let us understand what aLet us understand what a
virus IS NOTvirus IS NOT
A virus is not a germ,A virus is not a germ,
bacteria or organic virusbacteria or organic virus
A virus is not a malfunctionA virus is not a malfunction
of any devices or computerof any devices or computer
part.part.

140. 140
What, then is a VIRUS?What, then is a VIRUS?
It is a program that copyIt is a program that copy
itself, and then transfer fromitself, and then transfer from
one computer to anotherone computer to another
without users knowing it.without users knowing it.

141. 141
What, then is a VIRUS?What, then is a VIRUS?
 The program cannot be seenThe program cannot be seen
like an ordinary file. It is hiddenlike an ordinary file. It is hidden
within executable files or datawithin executable files or data
 It is made to either expressIt is made to either express
something through screen, or tosomething through screen, or to
infect and erase datainfect and erase data

142. 142
Things to do to in Virus AttacksThings to do to in Virus Attacks
Always BACKUP yourAlways BACKUP your
important dataimportant data
Install an anti-virusInstall an anti-virus
program on yourprogram on your
computer.computer.

143. 143
Things to do to in Virus AttacksThings to do to in Virus Attacks
 NEVER share floppy disk andNEVER share floppy disk and
other storage media with otherother storage media with other
computer users. Also don’t usecomputer users. Also don’t use
pirated software.pirated software.
 Don’t open or access unknownDon’t open or access unknown
files or attachment in the Internetfiles or attachment in the Internet
as these be affected by a virusas these be affected by a virus

144. 144
SafetySafety
Precautions forPrecautions for
Working on aWorking on a
ComputerComputer

145. 145
#1#1
Make notes as you workMake notes as you work
so that you can go backso that you can go back
step-by-step to checkstep-by-step to check
your work later ifyour work later if
necessarynecessary

146. 146
#2#2
When unpacking hardwareWhen unpacking hardware
or software, remove theor software, remove the
packing tape andpacking tape and
cellophane from the workcellophane from the work
area as soon as possiblearea as soon as possible

147. 147
#3#3
Keep componentsKeep components
away from your hairaway from your hair
and clothingand clothing

148. 148
#4#4
Keep screws andKeep screws and
spacers orderly and inspacers orderly and in
one place, such as aone place, such as a
cup or traycup or tray

149. 149
#5#5
Do not stack boardsDo not stack boards
on top of each other,on top of each other,
you could remove ayou could remove a
chip accidentally.chip accidentally.

150. 150
#6#6
When handlingWhen handling
motherboards andmotherboards and
expansion cards doexpansion cards do
not touch the chips onnot touch the chips on
the boardsthe boards

151. 151
#7#7
 Hold expansion cards by theHold expansion cards by the
edges. Do not touch anyedges. Do not touch any
soldered components on asoldered components on a
card, and do not touch chips orcard, and do not touch chips or
edge connectors unless it isedge connectors unless it is
absolutely necessary. Do notabsolutely necessary. Do not
touch a chip with a magnetizedtouch a chip with a magnetized
screwdriver.screwdriver.

152. 152
#8#8
Do not use a graphite pencilDo not use a graphite pencil
to change DIP switchto change DIP switch
settings, because graphitesettings, because graphite
is a conductor of electricityis a conductor of electricity
and the graphite can lodgeand the graphite can lodge
in the switch.in the switch.

153. 153
#9#9
Always turn off aAlways turn off a
computer before movingcomputer before moving
it. A computer’s hardit. A computer’s hard
drive always spin while itdrive always spin while it
is on, unless it has ais on, unless it has a
sleep mode.sleep mode.

154. 154
#10#10
Always turn off a computerAlways turn off a computer
before moving it. Abefore moving it. A
computer’s hard drivecomputer’s hard drive
always spin while it is on,always spin while it is on,
unless it has a sleep mode.unless it has a sleep mode.

155. 155
#11#11
To protect disks, keep themTo protect disks, keep them
away from magnetic fields,away from magnetic fields,
heat and extreme cold. Doheat and extreme cold. Do
not open the shuttle windownot open the shuttle window
or touch the disk’s surface.or touch the disk’s surface.

156. 156
#12#12
 The power supply and theThe power supply and the
monitor can hold amonitor can hold a
dangerous level of electricitydangerous level of electricity
even after you turn them offeven after you turn them off
and disconnect from aand disconnect from a
power source.power source.

157. 157
ProtectingProtecting
AgainstAgainst
ElectrostaticElectrostatic
DischargeDischarge

158. 158
ElectroStatic Discharge (ESD)ElectroStatic Discharge (ESD)
 Commonly known as static electricityCommonly known as static electricity
 An electrical charge that can build upAn electrical charge that can build up
on the surface of insulating materials,on the surface of insulating materials,
such as clothing or plastic.such as clothing or plastic.
 This is why touching a metalThis is why touching a metal
doorknob after you cross a carpet indoorknob after you cross a carpet in
your stocking feet can result in a veryyour stocking feet can result in a very
noticeable shock.noticeable shock.

159. 159
Why worry about ESD?Why worry about ESD?
 A charge of much less than 3000 voltsA charge of much less than 3000 volts
can damage electronic components .can damage electronic components .
 Walking across carpet can generateWalking across carpet can generate
1,500 to 30,000 volts of static1,500 to 30,000 volts of static
electricity.electricity.
 Just picking up a common plastic bagJust picking up a common plastic bag
can generate over 1,000 volts andcan generate over 1,000 volts and
often much more.often much more.

160. 160
How to prevent ESD?How to prevent ESD?
Ground Bracelet or AntistaticGround Bracelet or Antistatic
Wrist StrapWrist Strap
Ground MatGround Mat
Static Shielding BagStatic Shielding Bag

161. 161
Manual Way to prevent ESDManual Way to prevent ESD
 As you work on a computer, make aAs you work on a computer, make a
point of touching the metal frame orpoint of touching the metal frame or
power supply box before you touchpower supply box before you touch
any other part.any other part.
 Touch it again every time you moveTouch it again every time you move
around, this will at least equalize thearound, this will at least equalize the
amount of static electricity stored upamount of static electricity stored up
and waiting to move in you and in theand waiting to move in you and in the
PC.PC.

162. 162
Lab ActivitiesLab Activities

163. 163
Handling PC ConnectionsHandling PC Connections
 Identify the types of ports andIdentify the types of ports and
connectionsconnections
 You need a computer with standardYou need a computer with standard
peripherals attached including aperipherals attached including a
mouse, keyboard and monitor.mouse, keyboard and monitor.

164. 164
Opening a System UnitOpening a System Unit
 You need:You need:
PCPC
A Phillips screwdriverA Phillips screwdriver
Preferably an antistatic wrist strapPreferably an antistatic wrist strap
 Identify the internal parts of theIdentify the internal parts of the
System UnitSystem Unit

165. 165
Handling Expansion CardsHandling Expansion Cards
 You need:You need:
 A PC running WindowsA PC running Windows
 A Phillips screwdriverA Phillips screwdriver
 A straight-slot screwdriverA straight-slot screwdriver
 An Antistatic wrist strapAn Antistatic wrist strap
 A three-prong parts retrieverA three-prong parts retriever

166. 166
Identifying the Type ofIdentifying the Type of
CPU in Your PCCPU in Your PC
 A working PC running WindowsA working PC running Windows
 Paper and PencilPaper and Pencil
 ScrewdriversScrewdrivers
 An antistatic wrist strapAn antistatic wrist strap
 You need to know the manufacturer,You need to know the manufacturer,
model, speed and package.model, speed and package.

167. 167
Five ways to identify the type of theFive ways to identify the type of the
CPUCPU
 System InformationSystem Information
 My Computer PropertiesMy Computer Properties
 Physical ConnectionPhysical Connection
 RebootReboot
 CPU-Z (Application Program) canCPU-Z (Application Program) can
be downloaded at www.cpuid.combe downloaded at www.cpuid.com