introduction to information technology

1. University Of Buddhist and pali

2. About the lecturer
Dinesh Kumara Hakmana Abeynayaka Gunathilaka
• MBCS -CITP– UK
• MUKAP – University Of Greenwich

3. Subject Contents in General
• Computer Hardware
• Computer software
• Application programs
Word processing
Presentation
Spreadsheets
• Data & information management
• Computer networking
• Applications of networking: Internet, Intranet

4. Subject Content in Details
1.0 The Information Technology
Basic Information Technology Concepts
Computer History
Basic Components of Computer System
How a Computer System Works
2.0 Function of Major Computer Hardware
Computer Configuration and Classification
Central Processing Unit
Input-Output Devices and Peripherals
Secondary Storage
3.0 Basic Uses of Application S/ware & OS
Operating System and Its Functions
Disk Operating System (DOS) Primer
High and Low Level Languages
Assembler, Compiler and Interpreter
WINDOWS and MS Office Primer
4.0 Data Security
Importance of Backup
The Computer Virus Crisis
5.0 Computer and Network
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
LAN Components, Topologies and Types
Transmission Media

5. Objectives
• Describe the three fundamental characteristics of computers
• Describe at least four areas of society in which computers are
used
• Identify the basic components of a computer system: input,
processing, output, and storage
• List some common input, output, and storage media
• Distinguish data from information
• Describe the significance of networking
• Explain the significance of the Internet
• Explain the various classifications of computers

6. Course Assessment
Quiz 20%
Test 20%
Assignment 20%
Final Exam 40%
Total = 100%

7. Introduction to Computers
Computer hardware
Input, Output & peripheral devices
History of computers

8. Basic Components of a Computer System
What is computer?
An electronic device that can accept data (input),
process the input to useful information (process)
according to a set of instructions, store the
instructions and the results of processing (storage),
and produce the information (output).

9. Other definition:-
• A machine that can be programmed to accept data
(input), process it into useful information (output),
and store it away (in secondary storage device) for
safekeeping or later reuse
• Process is directed by software but performed by the
hardware
Basic Components of a Computer System

10. • Evolving more rapidly than Industrial Age
• Will continue into the current century
Information Age

11. Cornerstones of our Economy
• Land
• Labor
• Capital
• Information
Forging a Computer-Based Society:

12. Jobs
• From physical to
mental
• From muscle-power to
brain-power
Forging a Computer-Based Society:

13. A Computer in Your Future
• Where used?
– Bank withdrawal
– Supermarket
– Drive the car
• Do I need a Personal Computer?
– Campaign: One Home, One PC
– Many more use at work
• Will I use a computer in my future career?
– Almost every job will involve use of a computer

14. Computer Literacy
• Awareness
– Importance
– Versatility
– Pervasiveness in our society
• Knowledge
– What are computers
– How do computers work
– Terminology
• Interaction
– Use some simple computer applications

15. Is computer literacy enough?
• Need to be computer literate to manipulate
a computer
• Need to be computer fluent on computer
concepts as a basis to build deeper
knowledge
• Computer fluency make one able to
continue follow developments as computers
continue to evolve

16. Basic Information Technology
Concept
• Information technology - the use of modern
technology to aid the capture, storage, retrieval,
analysis, and communication of information.
• The various methods of delivering information are
by the use of data, text, image, and voice for
personal or organization needs.

17. History of Computers
• Man from centuries ago used a physical unit or sets
of units to represent numbers or quantities.
• A number or a quantity can be represented by a
physical thing, whether it is:
a pebble
a transistor
a bead of wirea mark on a bit of paper
a mechanical gear wheel
an electrical relay
a vacuum
tube

18. The Nature of Computers
Characteristics
• Speed
• Reliability
• Storage capability
Results
• Productivity
• Decision making
• Cost reduction

19. Where Computers Are Used:
Graphics
Graphs and charts
Animated graphics
Visual walk-through

20. Where Computers Are Used:
Education
• Teaching and
testing aid
• Learning by doing
• Computer-based
instruction

21. Where Computers Are Used:
Retailing
• Bar codes for pricing
and inventory
• Shipping

22. Where Computers Are Used:
Energy
• Locate oil, coal, natural gas, and uranium
• Monitor the power network
• Meter reading

23. Where Computers Are Used
:Law Enforcement
• National
fingerprint files
• National files on
criminal
• Computer
modeling of DNA

24. Where Computers Are Used:
Transportation
• Cars
• Run rapid transit systems
• Load containerships
• Track railroad cars
• Monitor air traffic

25. Where Computers Are Used:
Money
• Record keeping
• Banking by phone
• Credit cards

26. Where Computers Are Used:
Agriculture
• Billing
• Crop information
• Feed combinations
• Livestock breeding and
performance

27. Where Computers Are Used:
Government
• Forecast weather
• E-government
• Process immigrants
• Taxes
• Registration: birth, identity, car etc.

28. Where Computers Are Used:
The Home
• Educational tool
• Record keeping
• Letter writing
• Budgeting
• Drawing and editing
pictures
• Newsletters
• Connecting with others

29. Where Computers Are Used:
Health and Medicine
• Monitor patients
• Electronic imaging
• Diagnose illnesses
• Tele-health

30. Where Computers Are Used:
Robotics
• Perform jobs that are dangerous for
humans
• Factory work

31. Where Computers Are Used:
The Human Connection
• Assist the disabled
• Assist athletes by
monitoring their
movements

32. Where Computers Are Used
The Sciences
• Research
• Simulation
Connectivity
• Communication
• Telecommuting

33. Where Computers Are Used
Training
• Airline pilots
• Railroad
engineers
Paperwork
• Junk mail
• Term paper
• Record keeping

34. Computers are all around!
• Grocery store
• Schools
• Libraries
• Bank
• Mail
• Malls
We interact with computers everyday!

35. What computers can’t do yet?
Complex human activities
What else? Can you think of
others?

36. Computer System
People
Software
Hardware

37. People
• Computer programmer – person who
writes programs
• Users or End-users – make use of the
computer’s capabilities

38. Software
• Programs
• Set of instructions that directs the
hardware to do a required task
and produce the desired results

39. Hardware:
Basic Components of a Computer

40. Computer Components
1. Input Devices
- examples: keyboard and the mouse
- data entered on the keyboard and temporarily stored
in the computer’s memory and displayed on the monitor
2. System Unit
- contains the electronic circuits that cause the processing
of data to occur
- consists of central processing unit, memory, (RAM and
ROM)
and other electronic components
- CPU has a control unit and arithmetic/logic unit
- RAM temporarily stores data and program instructions
when they are processed

41. 4. Output Devices
- most commonly used output devices are monitor and
printer
- Monitor :commonly as CRT or Flat Panel Display
- Printer: Dot-Matrix, Ink-Jet etc.
5. Secondary Storage Devices
- also known as auxiliary storage devices
- stores instructions and data when they are not being
used by the system unit
- Examples : floppy disk and hard disk drive
Computer Components – cont.

42. Input Process Output
Data
Information
Storage
How a Computer System Works

44. How a Computer System Works –
cont.
Software
- The instructions needed to direct the computer to
complete specific tasks.
• The CPU follows the step-by-step instructions in a
program to complete the tasks from user.
• Operating system is the system software that controls
the basic, low-level hardware operations and file
management.

45. Microcomputers
- Also known as personal computers
- Physical sizes : palmtop, desktop and tower case
- Cheaper and smaller in size
Minicomputer
- Also known as departmental computers
- Physical sizes : small to large cabinets
- Support business application
Computer Configuration and
Classification

46. Mainframe
- Large computers with the capability to process
data at millions of instructions per second.
- Physical size : partial to full room of equipment
Supercomputer
- Most powerful and expensive computers
- Vast quantities of data manipulation
- Physical size : full room of equipment
- No. of users : hundreds of users
Computer Configuration and
Classification – cont.

47. Central Processing Unit (CPU)
- It is the heart of the computer, that is the microprocessor
chip.
- A highly complex, extensive set of electronic circuitry
that executes stored program instructions.
- CPU perform three main tasks :-
• Perform arithmetic operations
• Perform logic operations
• Retrieval and storage of data

48. - CPU consists of two main units :-
1. Arithmetic Logic Unit (ALU)
- arithmetic operations e.g. +, -, x, /
- logic operations e.g. >, >=, ==, <,
<=
CPU – cont.
2. Control unit
- fetches instructions from memory
- decode/translate instructions
- executes the processing tasks
- stores result in memory

49. CPU – cont.
- CU fetches instructions
from memory
- CU decodes/translates
instructions, directs
necessary data to ALU
- ALU executes
arithmetic/logic
instruction
-ALU stores results into
memory
What happens in a CPU?

50. Memory
- also known as primary storage, primary memory,
main storage, internal storage, and main
memory
- Consists of RAM and ROM
1. RAM (Random Access Memory)
- volatile; means the data exists only when power is ON
- two types of RAM, dynamic and static
2. ROM (Read Only Memory)
- non-volatile; means data permanently stored in and
cannot be changed
CPU – cont.

53. Function of Computer System
Data handling
I Input
P Process
O Output
S Storage

54. Processing: Batch vs. Interactive
• 2 types of information processing
– Batch processing
– Interactive processing : Real time

55. Input devices
• Accept data or commands and convert
them to electronic form
• Getting data into the computer
– Typing on a keyboard
– Pointing with a mouse
– Scanning with a wand reader or bar-code
reader
– Terminal

56. Output devices
Monitor or screen
• Text
• Numbers
• Symbols
• Art
• Photographs
• Video
Printer
• Black and white
• Color
• Convert from electronic form to some other
form
• May display the processed results
• Usable information

57. Input and Output Devices
1. Input devices
- Common type of devices used are the keyboard and the
mouse
- Standard type of keyboard is the QWERTY which has
86 keys (basic) and 101-102 keys (enhanced).
- Mouse is a pointing device for effective use of
computer interface. Trackball and touch pad are also
considered as pointing devices.

58. Input and Output Devices – cont.
Digitizer
- A pad with a pen-like stylus.
- The tablet sends electronic signals to the
computer, displaying the image drawn.

59. Input and Output Devices – cont.
the use of special equipment to collect data at
the source and send it directly to the computer.
Source data automation
MICR
ImagesOCR
Bar code Hand Written
Input devices– cont.

60. Input and Output Devices – cont.
2. Output devices
- most common devices are monitor displays and
printers
- Two types of display; flat panel display and CRT
display (Cathode Ray Tube)
- Two categories of printers; impact and non-impact
printers

61. Displays
1. Flat Panel
- commonly used in laptop, notebook
- examples of flat panel; LCD, Gas Plasma
2. CRT
- produce best images for computers
- two types of display; monochrome and color
- monochrome; displays one color (green or
amber)
- color; four types:
Input and Output Devices – cont.

62. Standard Graphic Add-on-Boards
Resolution
(by pixels)
CGA (Color Graphic Adapter) 640 x 200
EGA (Enhanced Graphic Adapter) 640 x 350
VGA (Video Graphic Array) 640 x 480
SVGA (Super Video Graphic Array) 1024 x 768
Displays – cont.
Input and Output Devices – cont.

63. Two types of printers (according to printing methods)
Impact printers
-use a physical contact with the paper to produce an
image
-e.g. dot matrix printer and line printer
Non-impact printers
-Place images on a paper without physically
touching it
-e.g. thermal, inkjet, laser printer
Input and Output Devices – cont.
Printers

64. Can you think of any other
input/output devices?

65. The Processor
Central Processing Unit (CPU)
• Converts data to useful information
• Interpret and execute instructions
• Communicate with input, output and
storage

66. Two Types of Storage
• Secondary storage
long-term storage
• Primary storage or memory
temporary storage

67. Memory / Primary Storage
• Temporary storage
• Holds input to be processed
• Holds results of processing
• Contains the programs to control the
computer and manipulate input into
output
• Volatile

68. Secondary Storage
• Long-term storage
• Non-volatile

69. Secondary Storage Examples
• Magnetic disks – read and written by
magnetic disk drive
– Hard disk
– Diskette
• Optical disks – read and written by optical disk
drives
– CD-ROM
– DVD-ROM
• Magnetic tape – read and written by magnetic
tape drives
– Primarily used for back-up

70. Magnetic Disk

71. • It is needed because
– Main memory stores data temporarily
– Main memory space is limited
Secondary Storage
 Benefits of secondary storage
 Space
 Reliability
 Convenience
 Economic

72. Computer System
• Computer
– CPU
– Memory
• Peripheral equipment
– Connected to the computer by a cable
– Input, output, storage

73. Computer Network
• Definition
– A system that uses communications equipment
to connect computers and their resources.
• Types
– Local area network (LAN) – connects computers
in close proximity
– Metropolitan are network (MAN) – connect
computers between buildings in the same
geographic area
– Wide are network (WAN) – connects computers
over great distances

74. Home Connectivity
• Connect home PC to other computers
• Use modem to convert signals
between electronic (computer) and
analog (voice) formats

75. Internet
• Collection of networks
• No ownership
• No central source for services available
• No comprehensive index of what information
is available
Individuals
Businesses
Organizations
Libraries
Research labs
Government
Connects Everyone!

76. Getting Connected
• User’s computer must connect to a server
• Server must communicate using TCP/IP
• The user can purchase access to a server
from an ISP (Internet Service Provider)

77. Internet – What Can You Do?
• WWW – World Wide Web
• FTP – File Transfer Protocol
• E-mail
• UseNet
• IRC – Internet Relay Chat
• Bulletin Boards

78. World Wide Web
• Browser – program that allows the user
to move around and explore the
Internet
• Use the mouse to point and click on
text and graphics
• Web page
• Web site
• Home page

79. Classifications of Computers
• Use the computer that fits your needs
• Based upon
– Size
– Speed
– Cost
– Portability
– Number of simultaneous users supported
– Available software
– Typical use

80. Personal Computers
• Other names
– PC
– Microcomputer
– Home computer
• Categories
– Low-end functional
– Fully powered
– Workstations
– Net computer or net box (Web TV)
• Desktop Models

81. Notebook Computers
• Portable
– Lightweight
– Fits in a briefcase
– Battery operated
• Laptop
– Larger
– Heavier
• More expensive that desktop models

82. Handheld Computers
• Personal Digital Assistant (PDA)
– Scheduling
– Addresses
– Handwritten input
– May offer wireless e-mail and fax
• PDA Phone
– More power than PDA
– Cellphone, GPS, MP3/MP4, Camera,
Video, TV, Radio etc.
– Runs various type softwares, serving various
applications

83. Other Types of Computers
Mainframes
– High speed
– More expensive
– Used to process large amounts of data quickly
– Support multiple users
– Does server tasks
Supercomputers
– Fastest speed
– Most expensive

84. What is a software?
- The instructions needed to direct the computer to
complete specific tasks.
- Software can be categorized into two types :-
Operating System and Its Function

85. Application Software
- program that tells a computer how to produce information
- examples of application software :
Business, scientific, educational programs and etc.
System Software
- program controlling the actual operations of the computer
equipments
- the operating system tells computer how to perform
functions such as load, store, execute application program,
transfer data between I/O devices and main memory
Operating System and Its Function
– cont.

86. Definition of OS :-
A set of programs that control and supervise a
computer system’s hardware
Purposes of OS :-
• To manage the hardware for efficient utilization of
computer resources
• To interface between a user/an application program
with the hardware
Operating System and Its Function
– cont.

87. • OS is made up of 2 programs;
Operating System and Its Function
– cont.
Control
Program
Service
Program

88. 1. Control program - three main functions
Operating System and Its Function
– cont.
Resource allocation allocate processor time, primary storage,
input and output devices
Job management to monitor, schedule and control programs
for its efficient processing
Data management -managing access to data for input of
information to printers,
disks/displays
- all hardware components activities are
controlled by the supervisor program

89. 2. Service programs
- provides services to the user/programmer
- services include language-translator programs and
utility programs
- language-translator program converts instructions from
English-like language to machine-language to be executed by the
computer
- utility program performs loading, saving, copying, keeping
track of files stored on a disk, preparing a formatted disk
Operating System and Its Function
– cont.

90. LanguageTranslator
Utility
Program
Other Services
Data M
gmt.
Job M
gm
t.
Resource Allocation
Supervisor
Operating System and Its Function
– cont.

91. What an Operating System does?
1. Checks the functionality of the computer’s hardware.
It generates an error message (by messages or beeps) if
any components are found faulty.
2. Then the OS control programs will load the supervisor
program into the computer’s memory – booting
3. Once the supervisor control program in memory, the
system displays the prompt sign (C:>), indicating that
it is ready to work

92. MS-DOS
 DOS is the supervisor program of the computer
 It does all the followings
• Interface to peripherals – How to interpret input, how to
process data, and how to produce output
• Application launcher – Most programming software, games
etc. use DOS prompt to run application
• Utility provider – Manage disks and files, prepare disks for
storage, copy files to a disk, to move or rename files, and to
delete files

93. MS-DOS – cont.
• Using DOS prompt to get command from user
• Examples for DOS operation
• DOS version/prompt type
• Modify date/time
• File and directory contents
• Clearing a DOS screen
• Going to subdirectory and back to root directory
• Searching for specific files
• Copy files from A drive / C drive

94. TYPES OF OS
 Microsoft Windows (98,
2000, XP, Vista)
 Mac OS (X)
 Linux OS (Hundreds of
even thousands of distros
ex: Red Hat, Ubuntu,
Mandrake etc. Visit
http://distrowatch.com/
for listing of Linux OS)
 Unix OS etc.

95. TYPES OF BROWSERS
 Mozilla Firefox
 Internet Explorer
 Opera
 Safari
 Konqueror
 Flock
Firefox is gaining
Popularity over IE
Flock

96. Low and High Level
Languages
Programming Language
- a set of written symbols that instruct the computer
hardware to perform certain tasks
- can be categorized as Low level Language and High Level
Language
Low Level Language
- Language that has the tendency towards specific,
delicate machine syntax
- Machine Language and Assembly Language

97. - consists of entirely 1’s and 0’s that only the computer
understands
- depends on different, specific hardware designs
- it executes very fast, but is time consuming and difficult to
understand
- only programmer who has the knowledge of the computer
architecture is able to understand the language
Low and High Level Languages
– cont.
Low Level Language – cont.
Machine Language

98. -also considered as Low Level Language because it still needs
specific knowledge of hardware
-it differs from machine language because of it uses
mnemonic in spite of 1’s and 0’s to represent the operation
codes
-mnemonic code is an alphabetic abbreviation that is easy to
remember
-it produce programs very efficient, less storage usage and the
execution is much faster
Low Level Language – cont.
Assembly Language
Low and High Level Languages –
cont.

99. - instructions resemble human language and mathematical
notation
- no detail knowledge of computer hardware and internal
operation of a computer
- easier to learn because of the English-like language rather
than understanding machine codes and instructions
- E.g. FORTRAN, COBOL, BASIC, Pascal, C/C++
Low and High Level Languages –
cont.
High Level Language

100. Assembler, Compiler and
Interpreter
Assembler
Compiler/Interpreter
(Source code) (Object code)

101. - the source code will remain unchanged after the conversion
but can be updated and changed, then compiled again
- after it is compiled, then the object code can be executed
-example of HLL program uses compiler is the C and C++
- the interpreter will translate a program one line at a time,
executing each line of the program after it is translated
- if an error should occur during execution, the error must be
rectified or solved before it can proceed to the next line
- example of HLL program uses interpreter is the BASIC
Assembler, Compiler and
Interpreter – cont.
Compiler
Interpreter

102. Importance of Backup – cont.
Data is exposed to several threats.

103. Uninterruptible Power Supply (UPS)
How does UPS works?
- it is connected in series with the computer system
- when power is interrupted, this result the UPS to function as a
backup supply of power to the computer system
- depends on the type of UPS, it will operate in 20 minutes or more
- it is advisable to backup important data within the time limit to
prevent any lost of data
Importance of Backup – cont.

104. Components of UPS
- one rectifier (charger) to convert AC to DC and to fully charge
the battery
- one battery to supply DC power to the inverter and the supported
time are based on the number and size of batteries
- one inverter to convert DC to AC
- one static bypass switch to control the load from/to the power
source to/from the battery and allows certain load to transfer
tolerances needed by the computer and its peripherals
Importance of Backup – cont.

105. The Computer Virus Crisis
The elements of a computer virus :
1. A set of instructions - a program being made to disrupt or
interfere other programs
2. Deliberately created - purposely created by humans or by itself
3. Actively propagates - reproducing itself
4. Infects other programs - contaminate or polluting different types
of programs
5. Able to do harm - can cause damage to others
6. Able to evolve - developing, growing and changing in
programs or systems

106. TheComputerVirusCrisis –
cont.
What are the damages of the virus to a computer system :
1. Creates garbage in your computer system that takes up space
in the memory and into your diskettes
2. Messing up files in their normal standard and altering some
of the files
3. Messing up the FAT (File Allocation Table) which contains
information of where are the other data's stored on your disk
4. Messing up the boot sector that can restrict your computer
from being able to execute at all

107. The Computer Virus Crisis–
cont.
Types of anti-virus software
The Computer Virus Industry Association (CVIA) in the USA
has developed three basic categories of anti-virus software.
To prevent initial
infection
To detect
infection
To identify and
remove viruses

108. COMPUTER NETWORKING
Network : Computers connected together to
communicate among
themselves.
Resource Sharing
File Sharing
Communication
PCs’ Administration and Security

109. - Computer network technology can be classified by the distance
the network technology is designed to span
- There are three types of networking :
Local Area Network (LAN)
Metropolitan Area Network
(MAN)
Wide Area Network (WAN)
COMPUTER NETWORKING –cont.

110. Local Area Network (LAN)
- Relatively small refers to the transmission media and
computer hardware
- The area is not exceeding 10 KM
- It only uses one type of transmission medium
- It share resources within building or campus
COMPUTER NETWORKING –cont.

111. Metropolitan Area Network (MAN)
- The network is larger compared to LAN
- The area covers a city of 10 to 100KM
- It requires efficient hardware and transmission
media
to cover these areas
COMPUTER NETWORKING –cont.

112. Wide Area Network (WAN)
- The network is larger than MAN and LAN
- It interconnect LAN of opposite sides of country or around
the world
- It covers huge geographical area in the world
COMPUTER NETWORKING –cont.

113. Local Area Network
Local Area Network
Router Multiplexer
Multiplexer
Modem
Modem
Front end
Processor
Host Computer

114. LAN COMPONENTS
Every LAN is made up of a standard set of components:

115. Topology: The physical connection among
computers within a network
- the topology is the configuration of the hardware and shows
which pairs of nodes can communicate
-there are three common types of topologies :-
LAN TOPOLOGIES
Star topology
Ring topology
Bus topology

116. Star
Ring
Bus

117. LAN PROTOCOLS
Protocol : A set of rules to access the network
to send data.
Two common LAN protocols

118. TRANSMISSION MEDIA
Transmission Media : The physical medium used for
transmission.
Types of TM
Coaxial
Cable
Twisted
Pair Cable
Fiber Optic
Cable
Satellite
Transmission
Microwave
Transmission

119. TRANSMISSION MEDIA - Twisted
Pair Cable
Colour-coded insulation
Jacket
Copper wire conductor

120. Inner conductor
Insulation
Outer plastic covering
TRANSMISSION MEDIA – Coaxial
Cable

121. TRANSMISSION MEDIA – Fiber
Optic Cable
Optical fiber
Protective outer
sheath
Glass covering
Strength wires

122. TRANSMISSION MEDIA –
Microwave

123. TRANSMISSION MEDIA – Satellite

124. ANY QUESTIONS OR ADDITIONS?