introduction to information technology

Institute of Product Design & ManufacturingUniversiti Kuala Lumpur

Introduction to Computers

Computer hardware

Input, Output & peripheral devices

History of computers

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).

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

• Evolving more rapidly than Industrial Age

• Will continue into the current century

Information Age

Cornerstones of our Economy

• Land

• Labor

• Capital

• Information

Forging a Computer-Based Society:

Jobs

• From physical to mental

• From muscle-power to brain-power

Forging a Computer-Based Society:

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

Video: Future of Information Technology

Computer Literacy

• Awareness– Importance– Versatility– Pervasiveness in our society

• Knowledge– What are computers– How do computers work– Terminology

• Interaction– Use some simple computer applications

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

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.

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 transistora bead of wire  a mark on a bit of paper   

a mechanical gear wheel  

an electrical relay 

a vacuum tube

The Nature of Computers

Characteristics• Speed• Reliability• Storage capability

Results• Productivity• Decision making• Cost reduction

Where Computers Are Used: Graphics

Graphs and charts

Animated graphics

Visual walk-through

Where Computers Are Used:Education

• Teaching and testing aid

• Learning by doing

• Computer-based instruction

Where Computers Are Used:Retailing

• Bar codes for pricing and inventory

• Shipping

Where Computers Are Used:Energy

• Locate oil, coal, natural gas, and uranium

• Monitor the power network

• Meter reading

Where Computers Are Used:Law Enforcement

• National fingerprint files

• National files on criminal

• Computer modeling of DNA

Where Computers Are Used:Transportation

• Cars

• Run rapid transit systems

• Load containerships

• Track railroad cars

• Monitor air traffic

Where Computers Are Used:Money

• Record keeping

• Banking by phone

• Credit cards

Where Computers Are Used:Agriculture

• Billing

• Crop information

• Feed combinations

• Livestock breeding and performance

Where Computers Are Used:Government

• Forecast weather

• E-government

• Process immigrants

• Taxes

• Registration: birth, identity, car etc.

Where Computers Are Used:The Home

• Educational tool• Record keeping• Letter writing• Budgeting• Drawing and editing

pictures• Newsletters• Connecting with others

Where Computers Are Used:Health and Medicine

• Monitor patients

• Electronic imaging

• Diagnose illnesses

• Tele-health

Where Computers Are Used:Robotics

• Perform jobs that are dangerous for humans

• Factory work

Where Computers Are Used:The Human Connection

• Assist the disabled

• Assist athletes by monitoring their movements

Where Computers Are Used

The Sciences• Research

• Simulation

Connectivity• Communication

• Telecommuting

Where Computers Are Used

Training• Airline pilots

• Railroad engineers

Paperwork• Junk mail

• Term paper

• Record keeping

Computers are all around!

• Grocery store• Schools• Libraries• Bank• Mail• Malls

We interact with computers everyday!We interact with computers everyday!

What computers can’t do yet?

Complex human activities

What else? Can you think of others?

Computer System

People

Software

Hardware

People

• Computer programmer – person who writes programs

• Users or End-users – make use of the computer’s capabilities

Software

• Programs

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

Hardware:Basic Components of a Computer

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

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.

Input Process Output

DataInformation

Storage

How a Computer System Works

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.

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

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.

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

- 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

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?

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.

Function of Computer System

Data handling

I Input

P Process

O Output

S Storage

Processing: Batch vs. Interactive

• 2 types of information processing– Batch processing– Interactive processing : Real time

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

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

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.

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.

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 Images OCR

Bar code Hand Written

Input devices– cont.

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

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.

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.

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

Can you think of any other input/output devices?

The Processor

Central Processing Unit (CPU)

• Converts data to useful information

• Interpret and execute instructions

• Communicate with input, output and storage

Two Types of Storage

• Secondary storage

long-term storage

• Primary storage or memory

temporary storage

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

Secondary Storage

• Long-term storage

• Non-volatile

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

Magnetic Disk

• It is needed because – Main memory stores data temporarily– Main memory space is limited

Secondary Storage

Benefits of secondary storage Space Reliability Convenience Economic

Computer System

• Computer– CPU– Memory

• Peripheral equipment– Connected to the computer by a cable– Input, output, storage

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

Home Connectivity

• Connect home PC to other computers

• Use modem to convert signals between electronic (computer) and analog (voice) formats

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!

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)

Internet – What Can You Do?

• WWW – World Wide Web

• FTP – File Transfer Protocol

• E-mail

• UseNet

• IRC – Internet Relay Chat

• Bulletin Boards

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

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

Personal Computers

• Other names– PC– Microcomputer– Home computer

• Categories– Low-end functional– Fully powered– Workstations– Net computer or net box (Web TV)

• Desktop Models

Notebook Computers

• Portable– Lightweight– Fits in a briefcase– Battery operated

• Laptop– Larger– Heavier

• More expensive that desktop models

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

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

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

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.

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.

• OS is made up of 2 programs;

Operating System and Its Function – cont.

Control Program

Service Program

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

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.

Language

Translator

Utility

Pro

gram

Other Services

Data Mgmt.Job

Mgm

t.

Resource

Allocation

Supervisor

Operating System and Its Function – cont.

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

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

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

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.

TYPES OF BROWSERS

Mozilla Firefox Internet Explorer Opera Safari Konqueror Flock

Firefox is gaining Popularity over IE

Flock

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

- 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

- 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.

- 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

Assembler, Compiler and InterpreterAssembler

Compiler/Interpreter

(Source code) (Object code)

- 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

Importance of Backup – cont.

Data is exposed to several threats.

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.

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.

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 itself3. Actively propagates - reproducing itself4. Infects other programs - contaminate or polluting different types

of programs5. Able to do harm - can cause damage to others6. Able to evolve - developing, growing and changing in

programs or systems

The Computer Virus Crisis – 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

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 detectinfection

To identify and remove viruses

COMPUTER NETWORKING

Network : Computers connected together to communicate among themselves.

Resource Sharing File Sharing Communication PCs’ Administration and Security

- 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.

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.

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.

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.

Local Area Network

Local Area Network

Router Multiplexer

Multiplexer

Modem

Modem

Front endProcessor

Host Computer

LAN COMPONENTS

Every LAN is made up of a standard set of components:

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

Star

Ring

Bus

LAN PROTOCOLS

Protocol : A set of rules to access the network to send data.

Two common LAN protocols

TRANSMISSION MEDIA

Transmission Media : The physical medium used for transmission.

Types of TM

CoaxialCable

TwistedPair Cable

Fiber OpticCable

SatelliteTransmission

MicrowaveTransmission

TRANSMISSION MEDIA - Twisted Pair Cable

Colour-coded insulation

Jacket

Copper wire conductor

Inner conductor

Insulation

Outer plastic covering

TRANSMISSION MEDIA – Coaxial Cable

TRANSMISSION MEDIA – Fiber Optic Cable

Optical fiber

Protective outer sheath

Glass covering

Strength wires

TRANSMISSION MEDIA – Microwave

TRANSMISSION MEDIA – Satellite

ANY QUESTIONS OR ADDITIONS?