Ba-332 Intro.to Information Technology

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BA-332

INTRO.TO INFORMATION TECHNOLOGY


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1.1 What is Information Technology?.............................................................1-1

1.2 Hardware..................................................................................................1-21.3 Software....................................................................................................1-31.4 Communication........................................................................................1-31.5 System Components.................................................................................1-31.6 Types of Software.....................................................................................1-41.7 Communication Medium..........................................................................1-4

UNIT 2: TYPES OF COMPUTERS..............................................2-1

2.1 Microcomputers........................................................................................2-2

2.1.1 Types of PCs..................................................................................2-22.1.2 Configuring a PC...........................................................................2-3

2.2 Network Computers..................................................................................2-32.3 Workstations.............................................................................................2-42.4 Mainframes...............................................................................................2-52.5 Supercomputers........................................................................................2-5

UNIT 3: INPUT DEVICES.............................................................3-1

3.1 Introduction..............................................................................................3-2

3.2 Keyboard..................................................................................................3-23.3 Mouse.......................................................................................................3-23.4 Touch Panel..............................................................................................3-23.5 Scanners....................................................................................................3-2

3.5.1 Optical Character Recognition.......................................................3-3

3.5.2 Optical Bar Recognition.................................................................3-3

3.5.3 Optical Mark Recognition..............................................................3-3

3.6 Pointing Devices.......................................................................................3-33.7 Magnetic Stripes.......................................................................................3-43.8 Smart Card................................................................................................3-4

3.9 Sound Input...............................................................................................3-43.10 Digital Camera..........................................................................................3-4

UNIT 4: OUTPUT DEVICES.........................................................4-1

4.1 Introduction..............................................................................................4-24.2 Monitors....................................................................................................4-2

4.2.1 Monitor Size...................................................................................4-2

4.2.2 Monitor Resolution........................................................................4-2

4.2.3 Flat Panel Monitors........................................................................4-3

4.2.4 Touch Screen Monitors..................................................................4-34.3 Printers......................................................................................................4-3


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4.3.1 Introduction....................................................................................4-3

4.3.2 Dot Matrix Painters........................................................................4-3

4.3.3 Laser Printers.................................................................................4-4

4.3.4 Ink-Jet Printers...............................................................................4-4

4.3.5 Plotters...........................................................................................4-4

4.4 LCD Projectors.........................................................................................4-54.5 Sound Output............................................................................................4-5

UNIT 5: PROCESSORS.................................................................5-1

5.1 Introduction..............................................................................................5-25.2 Components of a CPU..............................................................................5-2

5.2.1 The Control Unit............................................................................5-2

5.2.2 The Arithmetic and Logic Unit......................................................5-2

5.2.3 The Memory...................................................................................5-3

5.3 Serial and Parallel Processing...................................................................5-35.4 Platform....................................................................................................5-4

UNIT 6: STORAGE DEVICES......................................................6-1

6.1 Introduction..............................................................................................6-26.2 Magnetic Computer Tapes........................................................................6-26.3 Magnetic Computer Disks........................................................................6-2

6.3.1 Introduction....................................................................................6-2

6.3.2 The Diskette...................................................................................6-3

6.3.3 Hard Disks.....................................................................................6-3

6.4 Optical Disks............................................................................................6-36.5 Data Files..................................................................................................6-4

UNIT 7: TECHNOLOGY TRENDS..............................................7-1

7.1 Hardware Trends......................................................................................7-27.2 Implications of Increased Computerisation..............................................7-27.3 Emerging Technologies............................................................................7-3

7.3.1 Emerging Technologies for All the Senses....................................7-4

7.3.2 Emerging Technologies for the Internet Explosion.......................7-5

7.3.3 Emerging Technologies for the Wireless Revolution....................7-5

7.3.4 Emerging Technologies for Personal Life.....................................7-5

UNIT 8: APPLICATION SOFTWARE - PRODUCTIVITY.....8-1

8.1 Types of Software.....................................................................................8-28.2 Word Processing.......................................................................................8-2

8.2.1 Introduction....................................................................................8-28.2.2 Features..........................................................................................8-3


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8.3 Spreadsheets.............................................................................................8-48.3.1 Introduction....................................................................................8-4

8.3.2 How a Spreadsheet Works.............................................................8-4

8.3.3 Application of Spreadsheets...........................................................8-5

8.4 Databases..................................................................................................8-5

UNIT 9: APPLICATION SOFTWARE - OTHERS....................9-1

9.1 Desktop Publishing...................................................................................9-29.2 Electronic Mail.........................................................................................9-29.3 Digital Image Processing..........................................................................9-29.4 Voice Processing......................................................................................9-39.5 Presentation Software...............................................................................9-3

9.5.1 Select a Template...........................................................................9-4

9.5.2 Create an Outline for a Presentation..............................................9-49.5.3 Compile and Create Other Nontext Resources..............................9-4

9.5.4 Integrate Resources........................................................................9-4

9.5.5 Add Special Effects........................................................................9-4

9.5.6 Add Notes......................................................................................9-4

9.5.7 Make the Presentation....................................................................9-4

UNIT 10: SYSTEM SOFTWARE................................................10-1

10.1 Introduction............................................................................................10-210.2 The Operating System............................................................................10-210.3 Objectives of the Operating System.......................................................10-310.4 Graphical User Interface.........................................................................10-4

10.4.1 Text-based Software....................................................................10-4

10.4.2 Graphical-based Software............................................................10-4

10.5 Utilities...................................................................................................10-510.5.1 Introduction..................................................................................10-5

10.5.2 Functions of Utilities....................................................................10-5

UNIT 11: COMPUTER LANGUAGES......................................11-1

11.1 Introduction ...........................................................................................11-211.2 What is a 4GL?.......................................................................................11-3

UNIT 12: METHODS OF SOFTWARE ACQUISITION.........12-1

12.1 Introduction............................................................................................12-212.2 Custom Developed Software..................................................................12-2

12.2.1 Introduction..................................................................................12-2

12.2.2 Advantages...................................................................................12-212.2.3 Disadvantages..............................................................................12-2


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12.3 Packaged Software.................................................................................12-312.3.1 Introduction..................................................................................12-3

12.3.2 Advantage....................................................................................12-3

12.3.3 Disadvantages..............................................................................12-4

UNIT 13: COMMUNICATION MEDIUM.................................13-1

13.1 The Communication Channel.................................................................13-213.2 Communication Media: Wire and Wireless...........................................13-2

13.2.1 Twisted Pair Wire........................................................................13-2

13.2.2 Coaxial Cable...............................................................................13-3

13.2.3 Fiber Optics Cable.......................................................................13-3

13.2.4 High Speed Wireless....................................................................13-4

13.2.5 PCs Communicating Without Wires............................................13-513.3 Common Carriers...................................................................................13-513.4 Data Transmission in Practice................................................................13-6

UNIT 14: NETWORKS................................................................14-1

14.1 Introduction............................................................................................14-214.2 Network Topology..................................................................................14-214.3 Types of Networks..................................................................................14-214.4 Local Area Networks..............................................................................14-214.5 Advantages of Networks........................................................................14-3

14.6 Wide Area Networks..............................................................................14-414.7 Value-Added Networks..........................................................................14-414.8 Metropolitan Area Networks..................................................................14-414.9 Tiny Area Networks...............................................................................14-4

UNIT 15: TELECOMMUNICATION........................................15-1

15.1 Introduction............................................................................................15-215.2 Communication Hardware......................................................................15-215.3 The Modem.............................................................................................15-2

15.4 Network Interface Cards.........................................................................15-315.5 Special Function Communication Devices.............................................15-315.6 Network Configuration Factors..............................................................15-4

UNIT 16: TELECOMMUNICATION EQUIPMENT...............16-1

16.1 Overview................................................................................................16-216.2 Telephone...............................................................................................16-216.3 PABX......................................................................................................16-216.4 Voice Service..........................................................................................16-316.5 Fax..........................................................................................................16-3

16.6 Telex.......................................................................................................16-3


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BA332 INTRODUCTION TO COMPUTERS

UNIT 17: PROCESSING TECHNIQUES..................................17-1

17.1 Online Processing...................................................................................17-217.2 Real-Time Processing.............................................................................17-217.3 Configuration for Real-Time System.....................................................17-3

17.4 Interface of Online Systems...................................................................17-317.5 Batch Processing.....................................................................................17-317.6 Procedure for Batch Data Processing.....................................................17-317.7 Validation...............................................................................................17-4

UNIT 18: GOING ONLINE.........................................................18-1

18.1 The Internet.............................................................................................18-218.2 Going Online..........................................................................................18-218.3 The World Wide Web.............................................................................18-3

18.4 Who Controls the Internet?.....................................................................18-318.5 Connecting to the Net.............................................................................18-318.6 Retrieving and Viewing Information......................................................18-4

UNIT 19: SOFTWARE INTERFACES......................................19-1

19.1 Human-Computer Interaction.................................................................19-219.2 Commands..............................................................................................19-219.3 Menus.....................................................................................................19-219.4 Form Display..........................................................................................19-219.5 Dialogue..................................................................................................19-2

19.6 Graphical User Interface.........................................................................19-319.6.1 Introduction to Windows.............................................................19-3

19.6.2 Using Windows............................................................................19-3

19.6.3 Advantages...................................................................................19-3

19.7 Ergonomics.............................................................................................19-419.8 Multimedia..............................................................................................19-5

UNIT 20: TELECOMMUNICATIONS CONCEPTS...............20-1

20.1 Importance of Telecommunications.......................................................20-2

20.2 Type of Communication Networks........................................................20-220.3 Data Encryption......................................................................................20-220.4 Bandwidth, Speed and Cost of Transmission.........................................20-220.5 Communications Standards....................................................................20-320.6 Videotex/Viewdata.................................................................................20-320.7 Teletext...................................................................................................20-320.8 Comparing Videotex and Teletext..........................................................20-420.9 Videoconferencing..................................................................................20-420.10 Telecommuting.......................................................................................20-4


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INTRODUCTION TO COMPUTERS BA332

UNIT 21: DATA FILES & DATABASES...................................21-1

21.1 Introduction............................................................................................21-221.2 File Organisation....................................................................................21-221.3 Redundancy in Data Files.......................................................................21-3

21.4 Databases................................................................................................21-321.5 DBMS.....................................................................................................21-421.6 Data Dictionary.......................................................................................21-521.7 Advantages of Databases........................................................................21-521.8 Disadvantages of Databases...................................................................21-521.9 Creating a Database Environment..........................................................21-521.10 Physical and Logical Records.................................................................21-621.11 File Structures for Interrelating Data......................................................21-6


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UNIT 1

Introduction to Information Technology

Copyright 1995 by Thames Management Centre International. All right reserved.

No part of this lecture notes may be reproduced in any form or by any means,

without the permission in writing from Thames.


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1.1 What is Information Technology?

Most successful companies, collect, process and store data. Data are raw facts and everyday, wegenerate an enormous amount of data. Information is data that has been collected and processedinto a meaningful form.

Information is necessary for the smooth operations of a successful company and for planning andcontrol. With the large amounts of data that a company has to deal with, a less labour intensive andmore efficient method of managing information is required. This is where the technology of thecomputer is used. Thus, Information Technology refers to the integration of computing technologyand information processing.

A more formal definition of IT is:

The acquisition, processing, storage and dissemination of vocal, pictorial textual and numericinformation through the use of computer technology and telecommunication.

In an information society, knowledge workers focus their energies on providing a myriad ofinformation services. The knowledge workers job function revolves around the use, manipulationand dissemination of information.

Combining the technology of the computer and communication, information can be managed moreefficiently. Using IT in business leads to the following benefits:

Cheaper

Faster

More accurate

The technology itself can be divided into computer hardware and software and communications.

1.2 Hardware

Hardware is the physical, tangible equipment that is part of a computer system. Hardware can be

classified into the following components, according to the type of work it performs. Input

Output

Processing

Storage


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UNIT 2

Types of Computers





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2.1 Microcomputers

Microcomputers, also called Personal Computers (PC), are the most recent type of computer to bedeveloped. In 1981 IBM introduced the PCs. They are the smallest types of computers.Conventional PCs have a full keyboard, a monitor, and can function as stand-alone systems.

2.1.1 Types of PCs

PCs can be categorised as:

Pocket PCs

These are light, compact and highly portable. They have batteries and can operate with or withoutan external power source. The pocket PC, sometimes called a palmtop, can literally fit into a

pocket or a handbag.

Laptop PCs

These, at about 3 kilograms, are slightly heavier than the pocket PC. Often called a notebook PCbecause they are about the size of a thick notebook.

The power of the PC may not be related to its size. Some user conveniences must be sacrificed toachieve portability. For instance, input devices, such as keyboards and point-and-draw devices aregiven less space in portable PCs and may be more cumbersome to use. The display screen on some

pocket PCs is monochrome (as opposed to colour) and may be difficult to read under certainlighting situations. Portable computers take up less space and therefore have a smaller capacity for

permanent storage of data and programs. Laptop battery life can be as little as a couple of hours forolder models to 20 hours for state-ofthe-art rechargeable lithium batteries.

Desktop PCs

Tower PCs

Desktops and tower PCs are not portable because they rely on an outside power source and are notdesigned for frequent movement. Typically the desktop PCs monitor is positioned on top of the

processing component. The processing component of the tower PC is designed to sit upright. The

tower may be placed in any convenient location like the floor, nearby shelf or on the desk.

One person at a time uses a PC. The user turns on the PC, select the software to be run, enters thedata, and request the information. The PC like other computers is very versatile and has been usedfor everything from communicating business colleagues to controlling household appliances.


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Unlike the large computers, the processor is contained on one silicon chip, instead of acombination of chips. This processor in a PC is called a microprocessor. The commonmicroprocessors today are the 80486 and the Pentium chips manufactured by Intel.

2.1.2 Configuring a PC: Putting the pieces together

A typical multi-media configured PC includes the following

A microcomputer (the processor and other electronic components)

A keyboard for input

A point and draw device for input (usually a mouse)

A monitor for soft copy (temporary) output

A printer for hard copy (printed) output

A permanently installed high capacity hard disk drive for permanent storage of data and

programs

A floppy disk drive into which an interchangeable diskette, or floppy disk is inserted

A CD-ROM drive into which an interchangeable CD-ROM is inserted

A microphone (audio input)

A set of speakers (audio output)

A PC system is configured by linking a wide variety of peripheral devices to the processorcomponent.

2.2 Network Computers

In contrast to the conventional PC, the network computer or NC is designed to function only whenit is linked to a server computer (normally an organisations internal network of computers). The

NC looks similar to a PC but with several major configuration differences. First it has a relatively

small processor and considerably less RAM than modern personal computers. Second, it does nothave a permanent installed disk. And of course, it is less expensive than a stand alone PC.

The NC depends on a central network server computer to do much of the processing and forpermanent storage data and information.


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Here is the way an NC works. The network user has access to a wide range of applications.However, the software applications are downloaded as they are needed to the NC from a networkscentral computer. Whether or not to buy into the NC concept is one of major debates in theinformation technology community. Exchanging PCs for NCs will eliminate the expensive andtime-consuming task of installing and maintaining PC-based software, but it will make all NCsdependent on the server computer. If the server goes down, all NCs depending on it go down.

In the server computer of the NCs, the processor is much larger than the microcomputers andconsists of more than one silicon chip. Similarly, the size of the RAM is significantly larger.

The increased size of the CPU enables the server to be used by a number of NC at the same time,perhaps up to fifty. As technology improves, this number will increase.

Along the larger processor, the server will employ hard disks with even larger storage capacity asbacking storage and will often be used with faster printers.

2.3 Workstations

A workstation looks like a PC except that it is very fast. Speed is one of thecharacteristics that distinguish workstations from the PCs. In fact, some people talk

of workstations as souped-up PCs. The PC was fine for word processing,spreadsheets and games, but for real power users engineers doing computer-aideddesign or CAD, scientist and researchers who do a lot of number crunching,graphic designers, multimedia content developers, and so on the PC sometimesfalls short.

The workstations input/output devices also set it apart from a PC. A typicalworkstation will sport a large-screen colour monitor capable of displaying high-resolution graphics. For pointing and drawing, the workstation user can call on avariety of specialised point and draw devices that combine the precision of a gunsight with the convenience of a mouse. Add-on keypads can expand the number ofspecialised key available to the user.

The capabilities of todays high-end PCs are very similar to those of low-endworkstations. In a few years, the average PC will have workstation capabilities.Eventually the distinction between the two will disappear and we will be left with acomputer category that is a cross between a PC and a workstation.


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2.4 Mainframes

Until the late 1960s, all computers were mainframe computers and they were expensive. Largecompanies shell out $1.5 million and more for mainframe computers with less power than todays$1,000 PCs. In the late 1960s computer vendors introduced smaller computers that were moreaffordable for smaller companies. These were called minicomputers. This term is seldom used

today. Instead they are called midsized computers.

Mainframe computers are designed specifically for the multi-user environment, in contrast to PCsand workstations, which frequently are used as stand-alone computers. The amount of work thatcan be performed by the mainframe computer system is limited primarily by the speeds of theinput/output and storage devices.

Mainframe computers have very large processors with several hundred Megabytes of RAM. Thisallows them to be used by many users at the same time, maybe 200 or more.

This type of computer would usually be used with very large and fast peripheral devices and withmany hard disk units.

Since the number of users can be so high, there is quite a large processing task to control the flow

of data between the computer and all the terminals. For this reason, most mainframe computers usea minicomputer to handle this activity, thereby leaving the mainframe free to process the data. Inthese circumstances, the minicomputer is referred to as a Front End Processor (FEP).

2.5 Supercomputers

Supercomputers are used to process very large amounts of data very quickly. The speed of thesupercomputer may be 100 times that of a large mainframe computer.

These are representative supercomputer applications:

Enable the simulation of airflow around an airplane at different speeds and altitudes.

Auto manufacturers use supercomputers to simulate auto accidents on video screens.

Meteorologist employ supercomputers to study how oceans and the atmosphere interact to

produce weather phenomena. Hollywood production use supercomputers to create the advanced graphics used to create

special effects for movies and TV commercials.

The CRAY T90 supercomputer is one of the most powerful general-purpose computers.


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1.3 Software

Hardware only becomes useful when it is instructed to perform activities. Software comprises theset of instructions which tell the hardware what to do. The purpose of software is to cause thecomputer to provide the user with the data processing facilities required. These instructions areusually combined in a sequence. A set of such instructions is called a program.

Software are divided into:

System Software

Application Software

1.4 Communications

Today, telecommunications is intimately bound with information technology. Essentially, formaximum performance, computers must be linked to each other in order to exchange information.This can be done by cabling (if the computers are located close to each other), or, more commonly,

by using the telephone network to transmit data.

1.5 System Components

A computer system is made up of 4 hardware components, namely input, processing, output andstorage.

Input Device

A device which transfers data and programs to the internal memory.

Output Device

A device which receives the results of processing from the processor.

Processor

The main unit of a computer system. It accepts data from a input device, executesinstructions and performs operations on data as specified by the internally stored

program and outputs the results to an output device.

Storage Device

A computers auxiliary bulk storage device providing for the storage of data andprograms until required for processing activities.


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1.6 Types of Software

There are many different types of software, but are put into 2 main groups:

System Software

The system software takes control of the computer on start up and then plays acentral role in all interactions with the computer components.

Application Software

This is designed and created to perform specific personal, business or scientificprocessing task.

1.7 Communication Medium

In the global village, we can communicate with people electronically as easily as we might have aconversation with a neighbour. Depending on the distance between the computers, we may use oneor more of the following medium:

a) Computer Cables

Within the home or company premises, computers can be connected directly to eachother or in a network.

b) Telephone Network

Outside the home or company premises, we use the national telephone network orlink across countries through one or more telephone systems.

c) Undersea Cables and Satellite Systems

Over longer distances or across oceans, the undersea cables and satellite systems maybe used.


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UNIT 3

Input Devices





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3.1 Introduction

Computers are electronic devices which operate in a way not easily understood by humans. It isnecessary to have equipment that will convert the signals used by computers into a form that can

be used by humans and vice-versa. This is the role of input and output devices.

Input devices make it easier for non-technical, untrained users to input data accurately and quickly.Over time different forms of such devices have been introduced to suit varying requirements.

3.2 Keyboard

Probably the most familiar of the input devices is the keyboard. Generally this resembles theQWERTY type keyboard common on most typewriters. Unlike the typewriter keyboard, however,the computer is extended to contain up to 102 keys, which include a number pad, a series ofspecial function keys and some keys to control the cursor on the screen.

3.3 Mouse

The mouse is a small, plastic device which is connected to the computer by a small cable. It can be

moved across a tabletop and the cursor will move across the screen in the same way. The cursor isa light square or line which appears on the screen. Where the cursor is in the same position on thescreen as a desired item, the item can be selected by pressing a button on the mouse. This saves theuser having to type in the desired selection.

3.4 Touch Panel

Another device to assist selection of items on a screen is the touch panel. This is a touch sensitiveplastic sheet which is placed on the screen and connected to the computer. The user can selectitems by touching the part of the touch pad at the location where the described item is on thescreen. This will cause the touch pad to send an electrical signal to the computer and select thedesired item.

3.5 Scanners

A scanner can be used to capture an image of a document or a picture and store this in thecomputer. In this way, both graphics and text can be stored and retrieved.

Stored images can be used for a number of purposes. Graphics can be incorporated into reports andnewsletters. Scanned documents can be retrieved easily and reprinted, instead of having to searchthrough the registry.

In the retail sector, source data automation is made possible by the use of scanners. Laser scannerscould be mounted on checkout counters, in handheld consoles or penbased.

Scanning technology has made the following possible:

3.5.1 Optical Character Recognition (OCR)

This is the ability of the scanners to read text information into a computersystem. It captures pre-determined format (like a typed letter) or non-determinedformat (like your handwriting). OCR captures information and put it into aneditable format.

3.5.2 Optical Bar Recognition (OBR)

Reading of bar codes is one of the most widely used scanner technologies. Barcodes represent alphanumeric data by varying the size of adjacent vertical lines.There are a wide variety of bar coding systems. Information must be in a pre-determined format.

3.5.3 Optical Mark Recognition (OMR)

The scanner detects the presence or absence of a mark in a pre-determined place.The information must exist in pre-determined format on paper.


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3.6 Pointing Devices

There is a wide variety of pointing devices similar to the mouse.

Trackball

The trackball is a ball inserted in a small external box near the keyboard. The ball is

rolled with the fingers to move the mouse cursor. Some people like to think of thetrackball as an upside-down mouse with a bigger ball at the bottom.

Trackpad

The trackpad has no moving parts. One simply moves a finger about a small touchsensitive pad to move the mouse cursor.

Trackpoint

Trackpoints are usually positioned in or near a laptops keyboard. They function likeminiature joysticks but are operated with the tip of the finger.

Joystick

The joystick is a vertical stick that moves the mouse cursor in the direction the stick ispushed. Joysticks are commonly used in video arcade games.

Digitizer tablet and pen

The digitizer tablet and pen has a pen and a touch sensitive tablet whose X-Y coordinatescorrespond with those on the computers screen display.

3.7 Magnetic Stripes

The magnetic stripes on the back of charge cards and badges are another example of data entry atthe source. The magnetic stripes are encoded with data appropriate for specific applications. Forexample, account numbers and identification numbers are encoded on a card for automatic tellermachines. Magnetic stripes hold more data than the printed bar codes. Since they are also not read

easily, they are perfect for storing confidential data.

3.8 Smart Card

The smart card looks like any other charge card except it has a an embeddedmicroprocessor with up to 32 KB of non-volatile memory. Because the smart card canhold more information, has processing capability and is almost impossible to duplicate,smart cards may replace cards with magnetic stripes. A stored value card is an example ofthe smart card.

3.9 Sound Input

A microphone captures data that originate in audio form. The sound data can be

reproduced later or converted to text using a speech recognition system.

3.10 Digital Camera

A digitised image is captured when a digital camera is used. This image may be storedinto a diskette or on board flash memory.


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UNIT 4

Output Devices





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4.1 Introduction

New technology has resulted in the development of different output devices that serve a variety ofpurposes. The quality of the output has improved at a continually reducing cost. In this chapter, weshall review various output methods and devices.

4.2 Monitor

The most familiar of all output devices is the Monitor or the Visual Display Unit (VDU). When theterms screen or display are used, we refer to the part of the monitor where the output is shown.

The graphic adapter is the device for the monitor. All display signals en route to the monitor passthrough the graphics adapter, where the digital signals are converted to analog signals compatiblewith the monitors display capabilities.

Most existing graphics adapters have their own RAM called video RAM or VRAM, where theyprepare monitor-bound images for display. The size of the VRAM is important in that itdetermines the number of possible colours and resolution of the display, as well as the speed atwhich signals can be sent to the monitor. A minimum of 2 MB of video RAM is recommended.The newer AGP graphics adapters enjoy much better performance by using the PC systems RAMdirectly.

4.2.1 Monitor Size

Display screens vary in size from 5 to 30 inches (measured diagonally). The monitor size of desktop PCs is up to 17 inches.

4.2.2 Monitor Resolution

Monitors vary in quality of output or resolution. Resolution depends on:

The number of pixels that can be displayed

The number of bits used to represent each pixel

The dot pitch of the monitor

Pixels is the smallest addressable point on the screen. Most monitors can be set at a resolutionranging from 640 by 480 to 1600 by 1200. Each pixel can be assigned a colour. Most colourmonitors mix red, green and blue to achive a spectrum of colours and are called RGB monitors.When each pixel is 8-bit mode, there are possible 256 colours. The 16-bit mode has 65,536

possible colours. The dot pitch is the distance between the centers of adjacent pixels. Any dot pitchequal or less than .28 mm provides a sharp image.

4.2.3 Flat Panel Monitors

Laptop PCs use flat panel monitors. The most common technology uses Liquid Crystal Display(LCD) using millions of transistors.

4.2.4 Touch Screen Monitors

Touch screen monitors permit input as well as output.

4.3 Printers


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4.3.1 Introduction

Printers produce hard copy outputs, such as management reports, academic term papers, cashregister receipts, labels, memos, check, etc. There are various types of printers available whichgive a variety of different results. There are two main categories of printer:

Impact printer

Dot matrix printers

Non-impact printer

Laser printer

Ink-jet printers

4.3.2 Dot Matrix Printers

The dot matrix printer is the most inexpensive printer. This is an impact printer. Most impactprinters used in the office today are dot matrix printers.

The dot matrix printer form images one character at a time as the printer head moves across thepaper. The dot matrix uses from 9 to 24 tiny pins to hit an ink ribbon and paper much as atypewriter does. The dot matrix printer arranges printed dots to form characters and all kinds ofimages. Dot matrix printers print up to 450 cps (characters per second).

Most dot matrix printers can accommodate both cut sheet paper and fanfold paper. The tractor feedthat handles fanfold paper is standard with most dot matrix printers. Impact printers, unlike non-impacts, touch the paper and can produce carbon copies along with the originals.

The greater the density of pins, i.e. the greater the number of pins in the matrix, the better thedefinition of the letter will be, resulting in a higher printer quality. It follows that the more pins inthe matrix, the more the printer will usually cost.

4.3.3 Laser PrintersThe Laser printer is the most common type of non-impact printer. These printers use a laser tomark the parts of the page where the text or image is to be formed. The paper is passed through atoner solution where the marked areas pick up the toner and the text becomes visible. Laser

printers print on standard letter size paper.

These printers print at 4 to 32 pages per minute for text printing. Most of the laser printers in useprint shades of grey, however, colour laser printers are becoming increasingly popular as theirprice continues to drop. Printing in colour or graphic images may slow down output to about 25%of the text and non-colour speed.

The resolution of the low-end desktop printer is 600 dots per inch (dpi). High-end printers, whichare sometimes called desktop typesetters are capable of at least 1200 dpi. The dpi is the number ofdots that can be printed per linear inch horizontally and vertically.

Laser printers are quiet but are the most expensive.

4.3.4 Ink-Jet Printers

To the naked eye there is little difference between the print quality of some ink-jet printers andlaser printers. Resolutions for the typical ink-jet printers are about similar to that of the laser

printers. Printing speed range from 4 to 12 page per minute (ppm).

Ink-Jet printers are also able to print on normal paper. They work by spraying ink directly onto theappropriate parts of the paper using small jets. The quality of ink-jet printers is generally high anduse of different colour inks can be made for more complex prints. One major advantage is that ink-

jet printers can print on a wide variety of surfaces, in addition to paper, which makes them quite

versatile. Bubble-jet printers are ink-jet printers. The colour ink-jet printer is emerging as thechoice of budget-minded consumers.


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4.3.5 Plotters

Laser, ink-jet and dot matrix printers are capable of producing page-size graphic output, but arelimited in their ability to generate large-scale, high quality perfectly proportioned graphic output.Architects, engineers, graphic artists, city planners, and others who routinely generate high-

precision, hard copy output of widely varying sizes use another hard copy alternative called

plotters. Plotters use ink-jet technology to print on roll-feed paper up to 4 feet wide and 50 feet inlength. Plotters are used in large printing needs such as commercial posters and blueprints. Theycan be used to produce continuous output such as charts and earthquake activities.

4.4 LCD Projector

Computer generated graphics can be recreated on paper and transparency acetates with printers.Graphic images can also be captured on 35-mm slides, displayed on a monitor or projected onto alarge screen. The projection of images on the large screen uses the LCD projector. The LCD

projectors use their own built-in lens and light source to project the image onto the screen.

4.5 Sound OutputThe recording and playback of audio messages in a telephone message sometimes makes it seemlike we are talking to the computer. This is an example of the voice response system. Likemonitors, voice response systems provide temporary soft copy output. The recording convertssounds into digital data stored on disk or memory chips. When output occurs, a particular sound isconverted back into analog before routed to a speaker. All you need to produce speech and soundon a PC are sound expansion card and speakers (or headsets) and appropriate software.


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UNIT 5

Processors





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5.1 Introduction

The processor component of the personal computer system is a microprocessor or the CPU. Theprocessor runs the show and is the nucleus of any computer system. It can be thought of as thebrains of the computer, where the actual processing (thinking) is executed. The CPU variesfrom fingernail size to a postage stamp size.

5.2 Components of a CPU

The CPU is made up of 3 main parts:

a. The control unit;

b. The arithmetic and logic unit (ALU);

c. The memory

These parts are linked to each other and to the peripheral devices, such as input and output devices,through circuitry.

5.2.1 The Control Unit

The control unit is the part of the CPU that controls the activities of the rest of the componentsboth within and outside the CPU. It has three primary functions:

Read and interpret program instructions

Direct the operation of internal processor components

Control the flow of programs and data in and out of RAM

5.2.2 The Arithmetic and Logic Unit

The Arithmetic and Logic Unit (ALU) is the part of the CPU which actually performs all

computations (addition, subtraction, multiplication and division) and all logic operations(comparisons). Examples of computations include payroll, inventory levels, and banking services.The logic operation compares two pieces of data, either alphanumeric or numeric. Based on theresult of the comparison, the program branches out to one of several alternative sets of programinstructions. For example, in an inventory system each item in stock is compared to a reorder pointat the end of each day. If the inventory level falls below the reorder point, a sequence of programinstructions is executed that produces a purchase order.

5.2.3 The Memory

The memory is used for the direct storage of information. Data and programs are held in thememory for the period that it might be used for processing. There are two kinds of memory,

namely:a. RAM (random access memory)

b. ROM (read only memory)

RAM enables data to be both read and written to memory. RAM is an electronic circuitry and hasno moving parts. Most new PCs are equipped with synchronous dynamic RAM (SDRAM). This isable to synchronise itself with the processor, enabling the data transfer at more than twice thespeed of the previous RAM technologies.

RAM is volatile memory. That is, when the electrical current is turned off, or interrupted, the datais lost. In contrast to permanent storage on disk, Ram provides the processor with only temporarystorage for programs and data. All programs and data must be transferred to RAM from an inputdevice (such as a keyboard) or from a disk before programs can be executed and data can be

processed. Once a program is no longer in use, the storage space it occupied is assigned to anotherprogram awaiting execution.


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The ROM (read only memory) cannot be altered by the user. The content of ROM is hard-wiredby the manufacturer and can be read only. When you turn on the PC system, a program in ROMautomatically readies the computer system for use and produces the initial display screen prompt.A programmable Read only memory (PROM) is one where the user can load read only programsand data.

5.3 Serial and Parallel ProcessingIn a single processor environment, the processor addresses the programming problem sequentially,from beginning to the end. The processing speed is therefore limited by the speed of the channel.This is called serial processing.

Parallel processing involves having more than one processor and breaking the programmingproblem into pieces. Work on each of these pieces is then executed simultaneously in separateprocessors, all of which are part of the same computer system. In parallel processing, one mainprocessor examines the programming problem and determines what portion of the problem can besolved in pieces. Those pieces that can be addressed separately are routed to other processors andsolved. The individual pieces are then reassembled in the main processor for further computation,output or storage.

5.4 Platform

A platform defines the standard for which software is developed. Specifically, a platform isdefined by two key elements:

The processor for example, Intel Pentium II, Intel Pentium III, Intel Celeron,

Motorola PowerPC, etc.

The operating system for example, windows 2000, Mac OS X, Unix, etc.

Generally, software created to run on one platform is not compatible with any other platform. Thedominant PC platform is the Wintel PC. Wintel PCs use the Microsoft Windows control softwareand an Intel Corporation or Intel compatible processor. The other remaining PCs uses the AppleMacintosh line of computers or the Apple iMac line of computers. The Macintosh uses the MacOS operating system and the iMac uses Apples next generation operating system, the Mac OS X.Both are powered by Motorola PowerPC processors.


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UNIT 6

Storage Devices





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6.1 Introduction

The memory components of the CPU are quite expensive. Furthermore, they are volatile. For thesereasons, it is not practical to use the main memory to store large amounts of data permanently forfuture usage. In practise, different devices are used for the storage of data over a long period oftime.

The common storage devices are:

a. Magnetic computer tapes

b. Magnetic computer disks

c. Optical disks

6.2 Magnetic Computer Tapes

In terms of storage devices, tape is quite a cheap medium. However, this medium also has itslimitations. If the tape is used to store data which is not required quickly, as a security back-up forexample, then it is a cheap means of doing so. If the data has to be easily accessible, irrespective ofthe order in which it is stored, then tapes will require too much time to find the require data to beefficient. The saving on the cost of the tape will be lose due to the increased cost of retrieving dataheld on the tape.

Magnetic tape has three important functions:

Protection against loss of valuable files

Archiving files

File portability

6.3 Magnetic Computer Disks

6.3.1 Introduction

Disks are more expensive than tapes but have significant advantages. In terms of the speed ofretrieving data, disks are much faster than tapes. This is partly because it makes no differencewhere on the disk surface the required data is stored, since it can be accessed directly.

Each disk is divided into tracks and sectors.

The main types of disk are:

a. The diskette

b. The hard disk

6.3.2 The Diskette

Three types of interchangeable disk drives are commonly used in the PCs. They are the traditionalfloppy disk, the high capacity SuperDisk and Zip disk. The traditional 3.5 inch diskette, or floppydisk, is a thin mylar disk that is permanently enclosed in a rigid plastic jacket. It has 1.44 MB ofstorage space.

The SuperDisk can store 120 MB of data. Both the floppy disk and Superdisk are of the same sizebut have different disk density. Disk density is the number of bits of data that can be stored perunit area on the disk surface. The SuperDisk drive reads from and writes to the traditional floppydisk but not vice versa. The Zip drive reads and writes to 100 MB Zip disks.

The diskettes are not attached to the computer. Instead, they are inserted into a device called a disk

drive mounted on the computer. In this way, different disks can be used as and when required.


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This, of course, means that when a disk is full, another can be used so there is no restriction on theamount of data which can be stored.

6.3.3 Hard Disks

The two main objectives of the hard disk manufacturers are to put more data in less disk space and

to enable a more rapid transfer of data to and from RAM. The two main types of hard disk arethose that are permanently installed and those that are interchangeable.

Permanently installed or fixed hard disk are 1 to 5.25 inch permanent PC based hard disk hasstorage capacities of 4 GB to over 30 GB. Hard disks have data stored on both surfaces of thedisk. The disk spin continuously in a sealed enclosure. The enclosure keeps the disk surface freefrom contaminants. This contaminant free environment allows hard disks to have greater density ofdata storage than the interchangeable diskettes.

The interchangeable hard disks are getting more popular. The 3.5 inch Iomegas Jaz drive canstore 1 GB of data and is inserted and removed as easily as the 3.5 inch floppy.

6.4 Optical disks

The primary advantage of optical disks is that they are direct access forms of storage that can storevast amounts of data in a relatively small physical space. An optical disk device uses laser beamsto store and retrieve data. It works just like a compact disk player for a stereo system. One laser

beam writes to the recording surface by making pits in the disk and another reads the data from thelight sensitive recording surface.


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a. CD-ROM

One type of optical disk is the CD-ROM (compact disk read-only memory). Similarin concept to a ROM chip, these disks are read-only. Many PCs today have a CD-ROM drive installed. CD-ROMs offer a huge storage capacity (compared to floppydisks) at a relatively low cost. The capacity of a single CD-ROM is 680 MB.

The CD-ROM is manufactured by using special lasers to burn crevices in the disk.The spiral track on a CD-ROM is about 3 miles long with about 2 billion pits.

Once the master CD-ROM has been created, copies can be manufactured usingtechniques similar to those used to produce music CDs. Popular CD-ROM drives areclassified simply as 24X, 32X and 40X. This means they spin at 24, 32, and 40 timesthe speed of the original CD standard.

b. Recordable CD (CD-R)

For users who want to record data, a compact disk writer is used. This is a devicewhich uses a more powerful laser than a CD-ROM laser to record onto a CD-R. Therecordable compact disk is different from the CD-ROM.

c. Magneto-Optical Disk

The Magneto-Optical Disk is presently known as DVD (digital video disk). TheDVD can store up to 10 GB of data each. It is also backward compatible. This meansthat it can play all CD-ROMs and CDs. who want to record data, a compact diskwriter is used. This is a device which uses a more powerful laser than a CD-ROMlaser to record onto a CD-R. The recordable compact disk is different from the CD-ROM

6.5 Data Files

Organisational data, in order to be useful, has to be structured in such a way as to facilitate ease ofretrieval. This is achieved by grouping common data together in files. This is not a new conceptwith computerisation. Manual office systems used files to structure the information and computer

systems follow the same logic.The way in which data files for computerised systems are structured follows a set pattern. It is

perhaps easiest to consider an example. A common file in an organisation is the employee file inwhich all data relating to employees is held.

The file is divided into records. In an employee file, a record would be all the data relating to oneemployee. The file for an organisation with 500 employees, therefore, would contain 500 records.

Each record is divided into fields. The field is a particular data item which relates to a record. In anexample, the employees name would be one field, date of birth another. Each record in a filewould have the same set of fields. Each employee record, for example, would have a date of birthfield.


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UNIT 7

Technology Trends





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7.1 Hardware Trends

We are seeing the use of computers in more and more places not used earlier. They are also foundnow in places quite unexpected by some people. In the field of commerce, medicine,entertainment, government, and especially in communications, the computer is being seen asgetting indispensable to do more and better.

The processor chip is already found in most electronic and mechanical equipment.

a. Lower Cost and Greater Capability

Advances in materials science, manufacturing, and concepts of computing promise tomaintain the historic growth pattern in hardware power. Hardware prices havedropped while their capability has increased. The improved capabilities of thecomputer include higher speed and larger storage capacity.

b. Better Reliability

Hardware has become more reliable and has found uses in new and hostileenvironment not suitable earlier. There is greater confidence in using and knowingthat the computer system you have will not fail when needed.

c. Portability

Computers are becoming smaller and more portable. This can be seen in thenotebook and palmtop computers. Some computers have shrunk to becomewearable.

7.2 Implications of Increased Computerisation

The hardware trends have resulted, and will continue to result in greater usage of computers andinformation processing. Many or all aspects of a business organisation will be touched by the useof computers.

The increased presence of computers brings with it a number of issues and risks.


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a. Ethics

The use of computers in this electronic age is raising new ethical questions. A codeof ethics provides direction for computer professionals and users so that they actresponsibly in their application of information technology. A well-meaning

professional may violate a code of ethics because they may unaware of thetremendous detrimental impact of their actions. With the speed and power ofcomputers, a minor code infraction easily can be magnified to a costly catastrophe.

b. Misuse of Personal Information

Many people are afraid of the new technology because they fear the loss of privacy.The fear that computer based record keeping offers too much of an opportunity forthe invasion of an individuals privacy. For example, credit card users unknowinglyleave a trail of activities and interest that when examined can provide asurprisingly comprehensive personal profile.

The monitoring of e-mail by companies on their staff is seen by some as a violationof their privacy. Monitoring was to discourage non-business messages and to keepemployees focused on job-related activities. The responsible use of e-mail can boost

productivity. When abused, it can be counter-productive.

c. Computer Crime

There are many types of computer crimes, ranging from the use of an unauthorisedpassword by a student to a billion-dollar insurance fraud. Computer crime is seriousand the greatest amounts are linked to banking, insurance, product inventories,securities, etc. Fortunately only a small percentage of people with an inclination tocommit crime are capable of committing high-tech crimes. Criminals, like everyoneelse are moving towards information technology competency.

d. Negligence and Incompetence

Not all computer crime is premeditated. Negligence or incompetence can be just asbad for an organisation. Such crimes are a result of poor input/output control. Forexample, errors in data entry may result in unpaid bills when actual payments have

been properly made.

e. Hacking

Hackers or crackers are those that hack through a network security. They tap intothe network of commercial companies up to military high security installations.These criminals steal passwords, credit card numbers and vandalise web sites.


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f. Software Piracy

Intellectual Property Laws have been set up to protect the rights of software creators.Generally, an original software can only be installed to one original computer unlessstated in an agreement.

g. Viruses

Viruses are written by outlaw programmers to cause harm to the computer systems ofunsuspecting victims. Examples are Melissa, Chernobyl, Michelangelo, Friday the13th, Stoned and Jerusalem. Antivirus software is needed to routinely detect andeliminate these harmful programs.

h. Security

Proper administrative and logical controls are necessary to prevent or minimise thechances of deliberate and unintentional crimes.

7.3 Emerging Technologies

Many businesses are embracing new and high tech tools to offer its services to the world.

Information Technology is one of the most rapidly changing and dynamic aspects of the businessworld. Emerging technology falls into two types:

It is a technology that is so new that most businesses have not exploited it.

It is a technology that is fairly well established, but businesses have not fully

exploited it.

The first type includes electronic cash, and shopping in the internet. The use of multi-media isincluded in the second type. For both types, their importance lies in learning about them so as touse them effectively.

Emerging technologies can be grouped into four categories:

7.3.1 Emerging technologies for all the senses

These include applications that incorporate one or more of the following features:

Three dimensional images

Automatic speech recognition

Multi-media

Virtual reality

7.3.2 Emerging technologies for the Internet explosion

New technologies for the Internet continue to emerge. These includes:

Electronic cash

Communication through the internet such as internet telephony

7.3.3 Emerging technologies for the wireless revolution

These includes:

Smart phones


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Global positioning systems

Wireless local area networks

7.3.4 Emerging technologies for personal life

These include intelligent home appliances and smart cards. These technologies will definitelymake personal life easier and more exciting.


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UNIT 8

Application Software - Productivity





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8.1 Types of Software

Software falls into two categories. These are :

a. Application software

b. System software

a. Application Software

This is the set of instructions or programs which make the computer perform aparticular task which will satisfy a processing requirement of the user. An example isthe inventory system.

Application software are tools that save time, increase productivity and provide betterpresentation of information.

b. Systems Software

This is the set of instructions or programs which create a computer environmentwithin which the applications software can work.

Therefore, applications software determines what processing is done by thecomputer. Systems software determines how that processing will be done by thecomputer.

8.2 Word Processing

8.2.1 Introduction

The name of this software is virtually self-explanatory. A word processor is an applicationsoftware which allows the user to manipulate text so as to produce documents accurately andefficiently.

The software will provide the user with the blank screen page onto which text can be entered.

Once the text is on the page, it can be altered with the greatest of ease, thereby allowing thecorrection of errors and, perhaps more importantly, allowing the author of the document to changehis mind. When a document is finally complete, and the author wants it, then it can be printed andsaved.

The software will allow multiple copies of the same document to be printed at the touch of abutton. If a word still turns out to be incorrectly spelt, the document can be called up again, thecorrection made without retyping the whole document, and the page printed.

8.2.2 Features

a. Page Formatting

Some processors will allow the user to select different print fonts, set a variety of tabstops, indent margins on the left or both sides and select single, double or treblespacing.

b. Word Wrap

One of the most important features of word processor is that of word-wrap. Withmost typewriters, when the end of a line is reached, the bell rings to alert the user tothe need to press the carriage return to start a new line. With the word-wrap facility,the user merely continues to type and the word processor will continue onto a newline when required, without splitting words in the middle of them. Similarly, when

the end of the page is reached, the software will simply scroll the old page up thescreen and a new page will appear automatically at the bottom.


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c. Block Functions

Most word processors allow the user to identify blocks of text which can bemanipulated together. Blocks can be moved, copied or deleted. This facility is oftenused to allow transfer of blocks of text from one document (or file) to another,thereby allowing the repeated use of standard paragraphs in several documents.

d. Mail Merge

The more sophisticated word processors also allow a function known as mail merge.This is where a standard letter or other document can be produced, leaving gaps fordetails of the recipients name and address. These details, for a number of recipients,can be entered onto another file and the two merged together at the time of printing.This process would result in a copy of the document, complete with name andaddress, for each of the recipients held on the second file. Such a facility is nowadaysoften used in mailshots and circular.

e. Spell Checkers

Another feature which is of great use to users is that of the spelling checker. Thisfacility allows the user to check the spelling of any, or all, the words in the document

prior to printing. The software checks the spelling against an internal dictionary and apersonal one which would contain entries such as peoples names. One slightdisadvantage is that much of this software is produced in America and results in thespelling checker questioning words which are spelt differently in British to America.There are, however, spelling checkers available which use the British spellings.

f. Thesaurus

Finally, and as an extension to the spelling checker, there are now word processorswhich have the facility to a thesaurus to provide alternative words for the user. Thisagain is quite a useful tool and avoids having to use a manual method.

8.3 Spreadsheets

8.3.1 Introduction

A spreadsheet is essentially a grid made up of columns and rows. Numbers can be input into cellsand formulas defined to perform numerical computation. Spreadsheets are used to performrepetitive financial computations. There are several different spreadsheet packages on the market.

8.3.2 How a Spreadsheet Works

Despite the variation in the features and purchase price of each, they are all based on the samebasic concept. The software, when loaded, fills the screen with a grid formed of columns and rows.This resembles an electronic sheet of squared paper. Each of the squares is known as a cell andeach cell can contain either numbers, characters of formulae which are entered and manipulated by

the user. Each sheet of cells is known as a worksheet.

Just as squares on a map can be identified by their gird reference, so the cell on a worksheets canbe uniquely identified by a combination of letters and numbers by which the rows and columns arenamed. This is called the cell address.

If a cell contains a number, the number can be used in calculations elsewhere in the worksheet bythe use of a formula. A formula uses the numbers from other cells by referring to the address of thecell which contains the number. The package will use the number in the cell referred to, regardlessof its value. This means that if you change the number in the cell, the new value will be used in thecalculation without having to rewrite the formula. It is this ability to establish relationships

between cells, independently from the actual content of the cells, which makes the spreadsheetssuch a valuable financial tool.

Spreadsheets come with a variety of commands which allow the user to manipulate and copy data,set display formats and, often, produce graphical output. In the less sophisticated spreadsheets,


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these commands have to be remembered by the user whereas in the more sophisticated packages,there is a menu system which acts as a prompt from which the user can select.

The presentation of numerical data can be greatly enhanced with the use of graphs. In the moresophisticated spreadsheets, a variety of different types of graph can be produced from the data onthe worksheet. In broad terms, the more you pay, the more you get. This relates not only to thenumber of different types of graph, but also how easy it is to define and produce the graphs.

8.3.2 Application of Spreadsheets

As mentioned above, the most common use of spreadsheet packages is in the financial field. Theability to define the relationships between cells using formula enables the user to perform what-if? analyses.

An example of this would be a cash flow forecast for business which would entail an estimate ofpotential profits based on estimates of sales income minus costs of the sales and overheads. Oncethe formulae are set up, the values of the differences reflect the cash flow. Thus a number ofscenarios can be examined with little effort.

8.4 DatabasesA database is a collection of related data items that are stored together for use in many applicationsystems. In a company, we can find many application systems (e.g. personnel system), each ofwhich has one or more users. These applications may store all their data in a single database. Thus,many users will read or access data in that single database.

Users will usually access the database indirectly, by using the application system (e.g. personnelsystem). The application systems themselves do not access the database directly, but will useanother software called the Database Management System (DBMS).


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UNIT 9

Application Software - Others





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9.1 Desktop Publishing

An office technology that is currently enjoying considerable popularity is desktop publishing(DTP). Desktop publishing involves the use of desktop microcomputer systems that are equippedwith special hardware and/or software features, to produce documents that look as though theywere done by a professional print shop. In using these systems, users can combine word-processed

text with such elements as artwork, photos, and a variety of magazine style fonts. The overalleffect can be stunningly attractive.

DTP systems allow users to combine a variety of graphical fonts onto a page, use pre-stored artimages (call clip art) on pages, and draw lines and boxed to highlight text or art. Fonts and clip artcan also be purchased as add-ons from third-party vendors to extend the library of options offeredfor sale by the original-package vendor.

In some DTP systems, more sophisticated options are available. For instance, one can digitisecomplex arty images such as photos, which are composed of a variety of halftones to which onlyhigh levels or resolution can do justice. Also, there is a much greater variety of options availablewith fonts and clip art. For example, both fonts and clip art can be scaled to a variety of sizes and can be created or edited, as well.

9.2 Electronic Mail

Electronic mail (or E-mail) is the second largest EUC applications area, behind word processing.It refers to the technology used to send messages or documents from one electronic workstation toanother.

For instance, employees within a large organisation may have electronic mailboxes that aremanaged by a mainframe, minicomputer, or local area network. When these employees access aworkstation, they can call up their personal file or mailbox on the E-mail system to see if thereare any messages. Or, they can send a message to place in someone elses mailbox. These typesof E-mail systems are typically standard components in integrated office packages.

9.3 Digital Image ProcessingImages can be created using input devices or electronically copied from other sources. It couldcontain text, graphics or photographic data or a combination of these. The data can be stored,distributed, accessed and processed by computers and special-purpose workstations.

Digital image processing requires certain basic hardware and software. A scanner will be used totransform physical images into electronic digitised images, which must be indexed andcompressed.

Database management software handle the accessing of the indexed images. Workstationscomprise high resolution monitors to display images as well as large storage capacities to storeimage files.

9.4 Voice ProcessingVoice processing is a relatively new area. It can be limited to voice input processing, voice output,or both.

In the case of voice input processing, hardware and software are used to decipher speech andtransform it into computer signals. Often, the system has to be taught how to recognisecommands of the main person who will be using it. An example is found in some PCs where amicrophone is attached to process voice input. These systems are called speech recognitionsystems.

Voice output is also starting to be seen in some offices where the result of processing is a verbalmessage. For example, lifts in offices may be programmed to announce the floor. Often this isactually a pre-recorded message. The challenge is to be able to perform voice synthesis such thatthe computer can actually pronounce any word.


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A truly interactive system where commands and questions are issued verbally and where amachine can interactively respond (both in action and in verbal responses) is still some time in thefuture.

A speech recognition system captures both command and information that originate in audio form.Speech becomes converted to text when there are appropriate software and hardware. An exampleof software is generic vocabulary database while an example of hardware is a high qualitymicrophone with noise cancelling capabilities.

9.5 Presentation Software

PC based presentation software have in many instances replaced overhead projectors and slideprojectors. Presentation software lets you create highly stylised images for group presentations,self-running slide shows, reports and other situations that requires the presentation of organisedvisual information. The software gives a rich assortment of tools to create a variety of charts,graphs and images to help to make the presentation.

The following are steps to prepare a presentation using presentation software:


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9.5.1 Select a Template

Presentation software comes with many templates. Design templates are predesigned formats andcomplementary colour schemes with preselected background images that can be applied to anycontent material. Content template go one step further and suggest content for specific subjects; for

example, business plan, project overview, employee orientation, etc.

9.5.2 Create an Outline for a Presentation

PowerPoints tri-pane view lets you view the slide, outline and notes at the same time. This viewmakes it easy to add new slides, edit text, and enter notes while creating a presentation. The outlinefeature helps you organise your presentation material into a multilevel outline. People often importtheir outline from a word processing document.

9.5.3 Compile and Create Other Nontext Resources

A good presentation will include some or all of the following: photo images, charts andgraphs, a variety of eye catching clip arts, and even full motion video captured withdigital camera.With presentation software, you can create a variety of charts from data imported from aspreadsheet or a database.

9.5.4 Integrate Resources

Once all the text and visual resources have been compiled, it is time to integrate them intoa visually appealing presentation. Non text resources are added as and when needed,usually using the outline first. The slide sorter is used as it shows thumbnail images for allor much of the presentation on a screen. The slide sorter makes it easy to add or deleteslides and to rearrange them to meet presentation needs.

9.5.5 Add Special Effects

PowerPoint can make visually interesting transitions between slides during a presentation. Effectslike fading out text while fading in graphics can be used. Text and objects can be animated likeflying in effects. Sound effects makes the presentation more exciting.

9.5.6 Add Notes

Each slide can have corresponding notes. Notes and slides can be printed together as audiencehandouts.

9.5.7 Make the Presentation

The presentation can be to a single audience or to a group by projecting to a large screen. Or it canbe a self-running information center where screens are preset to display in a timed sequence.


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UNIT 10

System Software





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10.1 Introduction

The Operating System and Graphical User Interface (GUI), both System Software, are at the heartof the software action. All other software depends on and interacts with the operating system, thesoftware that controls everything that happens in a computer. Its graphical user interface (GUI)

provides a user-friendly interface to the operating system. System software encompasses those

programs that manage, maintain, and control computer resources. Programs designed to be used bythe end user are application software. The figure below shows the relationship between system andapplication software.

Operating

System

Graphical

User

Interface

Computer Games

Human Resource Management

Tax Planning

CAD

Spreadsheet Sales Summary

Income Statement

Office Inventory

Expert

System

Loan Evaluation System

Investment Management System

Relationship between System and Application Software

10.2 The Operating System

Just as the processor is the nucleus of the computer system, the operating system is the nucleus ofall software activity. Windows 2000, Windows 98, Windows NT, Mac OS X, and Unix are

popular operating systems for PCs and workstations. The Operating System is actually a family ofsystem software programs that monitor and control all I/O and processing activities within the

computer system. The computer system vendor supplies the operating system when you buy acomputer.

One of the operating system, often called the Kernel, loads other operating system and applicationsprograms to RAM as they are needed. The kernel is loaded to RAM on system start up andremains resident available in RAM until the system is turned off.

All hardware and software are under the control of operating system.

10.3 Objectives of the Operating System

In a general purpose computer such as a PC or a companys Internet server, the operating systemprovide the flexibility to tackle a variety of jobs. In dedicated computers like those in the arcade

games, controlled by a single function program, there is no need for a separate operating system.

All operating systems are designed with the same basic objectives in mind. However, mainframeand PC operating systems differ markedly in complexity and orientation. On the mainframe, multi-user operating systems coordinate a number of special function processors and monitor interactionwith hundreds, even thousands of terminals and PCs in a network. Most PC operating systems aredesigned primarily to support a single user on a single micro. This PC may or may not be linked toa network.

a. To facilitate communication between the computer system and the people who run it.- The interface through which users issue system related commands is part of theoperating system.

b. To facilitate communication amon

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Ba-332 Intro.to Information Technology

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