·COMPUTER LITERACY (OPERATIONS & APPRECIATION)

e.~ ,4'7ftJ, (M.Sc)

Department of Computet Science & Engineering, Ladoke Akintola University of Technology, Ogbomoso ·.

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All rights reserved . No part of this publication may be reproduced, stored in a retrieval system , or transmitted in any form by any means electronic, mechanical, photocopying, record ing or otherwise withou the prior consent of the author ~ C·.K Ayo.

1

FIRST PRINT 1994

ISBN 97t.8- 32919-0-4

~ ·

~ PRiNTEd iN NiGERiA by

·ALANUKITAN COMMEfiCIAI. PRESS {NIG.)lTD • .

l ~ r.o. Box 185 EGBB, KOGI ~m

ii

ion may be reproduced, any form by any means ng or otherwise withou1

1-4

NIG.)t.TD • .

iii

TO

Engr. & Mrs . T . 0 . Adeniyi

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iv PREFACE

This book is designed for t hose who are curious about the prolifera­tion, domination and use of Computer systems. The book to a greater extent is intended to be a companion for students of whatever class , workers and every household in particular .

The contents of the book is tailored to suit the courses taug ht in the tertiary institutions such as introduction to computers, computer application packages among others; and the syllabi of some profession­al bodies like Institute of Chartered Accountants of Niger.ia (ICAN) , and Chartered Institute of Bankers of Nigeria (CIBN) etc are also catered for.

The book is a two in one. That is it serves a textbook on one hand and a training manual on the other hand . The chapters are arranged in an order to enhance continuity of concepts which will go a very long way to give the addressed audience a solid computing foundation . Many topics of interest such as Comp~uter configuration , Program development , Application packages and the Computer virus among others are treated to the satisfaction of the targeted aud ience.

The book is therefore recommended for students of the university, and poly-technic, students undergoing computer training cour .>c s

organized by some vocational centres and in faCt, every household.

C. K. Ayo June 1994

Them many in operato Th e au't instituti1

INSTJTll

Th e ai

current

(a) La' I

Depa

(d) BE Agba

(e) CT Victo La go

underlist

(a) Dr .

Head, C LA UTE

iv

about the prolifera-1e book to a greater ; of whatever class,

ourses taught in the mputers, computer of some profession­: Niger.ia (ICAN), and etc are also catered

xtbook on one hand oters are arranged in 1 will go a very long mputing foundation . 1figuration, Program llputer virus among ted audience. tts of the university,

C. K. Ayo June 1994

v ACKNOWLEDGEMENTS

The materials in th is· text is a result of expertise contributions form many individuals of high repute, institutions, and experienced computer operators that helped in no small way to the realizat ion of my goals. The author is therefor~ grateful to the underlisted individuals and institutions for their immeasurable contributions.

INSTITUTIONS

The author is grateful for the material support in terms of texts, current journals and equipment from the following institutions :

(a) Ladoke Akintola University of Technology, Depar tment of Computer Science & Engineering, Ogbomoso .

(b) FACTS Computer Training Centre, Pl antation road, llorin.

(c) KEM Computer Training Centre, Beside Society General Bank, Taiwo Road , llorin.

(d) BENANT Computer Solutions , Agb a Ro ad, llorin .

(e) CTS (Nig) Ltd, Victorial Island , Lagos.

SPECIA LISTS

The author is particularly gratefu l for the contributions of the underlisted fellows who took their time to go through the tex~ ~nd again for thei r valuable suggestions .

(a) Dr . M . 0 . A digun ,

Head , Computer Sc . & Eng. Department, LAUTECH, Ogbomoso .

(b) Dr . A. 0 . Fakilede, Dept. of Mechanical Engineering. University of llorin .

(c) Mr. A . E. Okeyinka, Dept. of Computer Sc.& Engineering, LAUTECH, Ogbomoso .

(d) EAgr. 0 . 0. Abiona , Dept. of Computer Sc. & Engineering , LAUTECH , Ogbomoso .

Others

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The author is grateful to the following for their supports and encouragements:

Dr . J. Adeojo , Prince F. Ashagun , T . Agbana, 0 . Oniyide , I. 0 . Aderinwale, Z. 0. Arowoyele, V. F. Ojelabi, F. Ogunbayo, S. Audu, 0. Olanrewaju , 0 . Fatoye, L. Olaniyi, 0 . S. Ogirima , R. Oyenihi , F.

Owolabi and A . Olayemi. Finally, I am grateful to my wife Moji, for the understanding shown

dll ti.ing the period, and my children Juwon and Tala for not insisti ng on

my presence at home.

I

work . he has reading

vi

g,

lowing for their supports and

T . Agbana, 0 . Oniyide, I. 0. jelabi, F. Ogunbayo , S. Au?u , 0. o. s. Ogirima, R. Oyemhl , F.

oji, for the understandin~ ~hown NOn and Tola for not insisting on

vii FOREWORD

The Computer Technology has come to stay with us with its profound impact on every aspect of our lives. Perhaps this is the reason why Computer literacy is almost becoming the prime requ irement when one is competi ng for any skilled job today. We are fast moving away from the Computer-Centre-based arrangement which confines the Comput­ers to a particular section of an organisation. The reality is that the factory machinery is Computer-based; air-line reservations depend on the Computer ; personnel, financial, and administrative procedures have become computerised; including the command and control functions of the military ar.d the police . The writers and journalists also need the word-processor to prepare their writings personally or at least edit the work after first typing. Therefore this book has come to contribute to the computer literacy needs of the majority of people willing to becom_e relevant to this computer age.

The rich information contained in this book will suppleme nt or completely replace short-term Computer trainings which now abou nd provided you use it as your companion during hands-on sessions ®1'1 a computer. The skilled person may even find the contents a goo.d referonce whenever he intends to refresh his or her memory.

The wealth of experience of the author as a former polyte-chnic lecturer and now a University teacher has been brought to bear on this work . He has presented very succinctly and clearly the concep-ts that he has had to teach over the past ten years. It is hoped th at - the read ing public will find the book very useful.

DR. M. 0. ADIGUN LAUTECH, OGBOMOSO

CONTENTS

PREFACE

ACKNOWLEDMENT

FOREWORD

CHAPTER ONE

HISTORY/EVOLUTION OF COMPUTERS

What is a Computer? Development of Calculating devices Mech'1nicai/Eiectronic Computers Landmarks in the history of Computers

CHAPTER TWO

CLASSIFICATION OF COMPUTERS

Classification by type Classification by purpose Classification by age of technology Classification of Integrated Circuits (IC) Categories of Computers·

CHAPTER THREE

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MICROCOMPUTER: EVOLUTION AND CONFIGURATION

Interacting with the Computer Microprocessor and Microcomputer Microcomputer configuration Peripheral devices

iv

vii

:HA

iom

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CHAPTER FOUR ix

iv COMPUTER HARDWARE 30

v Fundamentals of the Co111pu tcr sys tem Information tran sfer between un1ts of the com puter

vii Typ es of memory Type s of Processor

HAPTER FIVE

FILE ORGANISATION AND PERIPHERAL DEVICES 42

Types of file organisations and methods File activities

Special ised 1nput/Ou tput devices Special ized Computer media equipment

HAPTER SIX

COMPUTER SOFTWARE 54

Classification of Computer Programs Features of Operating Systems Language translators

Advantages /Disadvantages of programming languages Software generations

HAPTER SEVEN ~ATION 17

MICROCOMPUTERS AND DISK OPERATING SYSTEM(DOS) 63

~eneral overview of the various DOS iles and directories

Some DOS Commands

CHAPTER EIGHT

COMPUTER A PPLICATION PACKAGES

Advantages/Disadvantages of appli cat ion packages Wordprocessing packages Practical example with word perfect 5.1 Spreadsheet packages Practical example with LOTUS 1-2-3 ver. 3. 1 Database M anagement packages Practical example with Dbase IV Statistical packages Practical example with SPSS PC+ v-e rsion 5 .0 Graphical Packages Practical example Hardware Graphic 3.0 Desktop publishing packages Description of windows 3 .1 and its applications (write, paintbrush, Aldus page maker, Corel draw publisher)

CHAPTER NINE

PROGRAM DEVELOPMEN

Programming steps System and program fl~wcharts Overview of BASIC programming Sample BASIC programs Overview of COBOL programming

CHAPTER TEN DATA PROCESSING

· Data and information Methods of data ,processing Data processing operations lnfotma.tion System Life Cycle

I

.,

X i APTER

7! ,p persc )ivisionJ unction

APTER

JFORM

entraliz ecentra istribut ariou s ~ latch, G

' and Vent uf-PTER

DATA

1ventio

X

=>ACKAGES

packages

3 .1

n 5 .0

HAPTER ELEVEN

DATA PROCESSING(DP) PERSONNEL 75

!>P personnel ~ i v i s ions in a DP department =unctions of the personnel

tAPTER TWELVE

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191

FORMATION PROCESSING ORGANISATION AND TECHNIQUES

:entralized system •ecentralized system »istributed system (arious processing techniques ~atch , Online, Time-sharing etc)

197

cations , Corel draw and VenturiAPTER THIRTEEN

DATA COMMUNICATION DEVICES & COMPUTER NETWORK204

1ommunication devices and carriers

14 omputer netw ork topologies peal Area Network (LAN) Vide A rea Network (WAN)

APTER FOURTEEN

COMPUTER SYSTEMS SECURITY AND THE VIRUS SAGA 211

bmputer systems security methods mputer systems control methods

1 e virus saga st of some viruses evention and cure of vi ruses

y

CHAPTER FIFTEEN

IMPACT OF COMPUTERS ON OUR SOCIETY

The need for Computer Computer and unemployment How computer creates jobs

GLOSSARY

INDEX

REFERENCES

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ard- INDEX

by Abacus 2 Data Processing cycle 186

tion ABC 6 Data Entry Clerk 195 Algorithm 144 Database packages 100

, ALU 34 Dbase IV 102 hat ( Analog Computer 11 Decentralized System 198 hie Analytical engine 4 Decision Support system 190

Artificial intelligence 14 Desktop Publishing Packages ASCC 6 134 Assembler 58 Difference engine 4 Assembly language 57 Digital Computer 11

rice Basic Programming 149 Dir 70 Batch Processing 200 Directories 65 Bits 31 Disk drives 25 Boot Sector Virus 216 Diskcomp 71 Bootstrap 36 Diskcopy 71 Bus Topology 208 Distributed System 199 Cache memory 35 DMA 33 CD-ROM ____:__---- 50 DOS 64 Centralized System 198 DP Manager 193 CHOIR 72 Dump Terminal 46 CHKDSK 72 EDP 185 Cis 70 ED SAC 7 Cobol programming 182 EDVAC 7 COLO SUS 6 EN lAC 6 Compiler 58 EPROM 36 Computer 2 Erase 72 Computer Network 206 Expanded memory 37 Conventional memory 37 Expert System 1.4 Copy 71 Extended memory 37: Core Memory 35 File Virus 216 Corel draw 139 Format 70 CP/M 64 Front-end Processor 206 CPU 31 Full-duplex_ Transmissi9n 706 CUI 18 General purpose Computer 12 Data Processing System 190 Generation Fite Seci.Kity 214 Data Processing department Generation Qf Computer 13

192 · ·Graphical Pat;kages- 124 Datct 185 GUl 18

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Half-duplex Transmission 206 Modem 205 Harvard graphics 124 More 73 High Level language 57 Mouse 28 Hybrid Computer 11 MS-Dos 64 1/0 Bus 32 Multi-plexer 205 IBM 5 Mult i-processing I 203 ICL 7 Multi-programming 202 ICONS 19 Multi-tasking· 203 Index Sequential f ile 44 NORTONS 215 Information 185 Notebook Computer 19 Information System life cycle OCR 53

189 On-l ine Processing ) I 201 . Integrated Circuit 13 Operating System 55

Intelligent terminal 46 Operations Manager 195 Interpreter 56 OS/2 64 Inverted file 45 Page Maker 139 Keyboard 22 Paper t ape 46 KeyDisk . 50 PC-Dos 64 KeyT~pe 50 PC~ TOOLS . 215 LAN 209 Pen Computer 20 Langua9~ Translators 56 Peripherals 31 Laptop ;Computer 19 Personal Computer 19 Librarian 196 Physical Control 2 13 Lotus 1-2-3 86 Portable Computer 19 Low level language 57 Printers 28 Machine language 57 Procedural Control I 213 Magnetic Tape 48 Program Flowchart 145 Magnetic Disk 49 Program 55 Mainframe Computer 16 Programmer ' u":j 195 MAR r1= 36 PROM ~ l_,l' ~ 36 Mark-1 ~'t~) • ..._v-... •1 6 Punched cards tr ~\\ 5 MDR . L

I 36 Pbnched Cards 47 MEM 73 RAM 36 Memory Unit 34 Random file 44 Menu • c, I 18 Real-time Processing 201 MICR ~ 52 Recovery Plan 214 M icrocomputer 15 Rename 74 Microfiche ~ r.: ~- I 52 Ring Topology ... ,.(..-, 207 Microfilm- I'"'"> .c~ .....

51 ·Robot "1-., ) J.' 223 Microprocessor ·'~ ~--~I il' 19 ROM . 36 Minicomputer 15 Root Directory -65

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'•. ' ' .. . ,. ' •

. ,

~ . SemicOr_iductor memory 35 ... Sequential file 43 3 -~

serial file a· l 43 S_implex :Transmission 206 ~ . ' . ·,smart Terminal 46 5

-~ Software generations 59 3 t · · 'Special-purpose computer 12 . 2 ..

,~preadsaeet Packages 85 3 5 ... . SPSS 114 9 ·~tar Topology 207

SUt~is.tical Packages 114 3 ,. 't . Super c·~mputer 16 1

4

· • Sy~tem lJnit 22 5 . · ' · Sy~tem& Security 212 5 ..

-Syst~ms Flowchart 146 4 ~ .. , .... t

Systems Analyst 194 9 6 e. Teleprocessing 201 4 Time-sharing System 202 5 .... Trojan Hors~ Virus 216 , . .0 Type 74 ,1 .UNIVAC 7 9

' \Upper memory 37 3 ~ Utility P~ograms 60 9 , . VOU (Monitor) 24 8

• J • _1 y~ntura Publishers 141 3 ~ ~iflual Memory 35 5 . WAN · 210 5 Win/NT 64 5 Windows 135 16 Word/w6rd length 32 5

' ' Word processing Packages 77 -7 - , Wc;»rdperfect 79 ra ;. Xcopy 74 ~4 Xenix/U~x 6"4 )1

14 .. 74 )7

23 36 t

65

255

Half-dt Harvar High L, Hybrid 1/0 Bus IBM ICL ICONS Index S Inform a Inform a

. lntegrat, lntelligeJ lnterpre1 Inverted Keyboar, KeyDisk KeyT~pe LAN Langua9·E L~ptop C Librarian Lotus 1-: Low level Machine I Magnetic Magnetic Mainframt MAR Mark-1 MDR MEM Memory U Menu MICA Microcom,:: Microfiche Microfilm Microproce Minicompu·

1.

2.

3.

4.

5 .

' 6.

7.

8.

9.

10.

REFERENCES

A yo K.C. (1991 ), Getting to know the computer. 2nd Edition, Newlight Computers, Kaduna.

Glyn Emery (1980), Elements of computer science. 2nd Edition, PHman Press, London .

Gordon B. Davis (1985), Introduction to comouters, 3rd Edition, McGRAW- Hill inc. London.

James Radlow (1986), Computers and the information society McGRAW - Hill Inc, New York.

James P. Hayes (1988), Computer Architecture and organization. 2nd Edition, McGRAW- Hill, New York.

R.C. Holland (1986), lntergrate.d Circuits and Microprocessors. Pergamon Books Ltd. New York.

Ralph M. Stair Jr. (1986), Computers in Todays World IRWIN Inc. U.S.

Richard W. Brightman & Jeffrey M·. Dimsdale (1986), ~ comcuters in an Information Age. Delmar Publishers Inc. New York.

INMAC (1989) ·computer users catalog• 77th Edition. U.S.

PCNOVICE (1992) •Finding the right Portable Computer• 3(1 0) u.s.

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