Taxmann's Computer Applications in Business

Preface to Seventh Edition

It gives us immense pleasure to put before you the thoroughly revised seventh edition of our book “Computer Applications in Business”. The earlier editions of the book along with our previous titles “Fundamental of Computers and Information System” and “Essential Tools” were well received by the readers for which we are thankful from the core of our hearts. With great enthusiasm and pride we place before you the seventh edition of the book and feel that the book in your hand will also come up to the expectations of the readers.

Besides covering the syllabus of papers titled “Computer Applications in Business” of B. Com(H) Semester IV of University of Delhi, this book also covers the syllabus as proposed under Choice Based Credit System (CBCS) pan India. The Book has been divided into twelve Chapters. The book besides covering theoretical aspects, lays major emphasis on practical applications. A separate Chapter has been added to illustrate how excel is useful in business decision making and data handling. This revised edition also includes two new Chapters. “Basic Internet Terminologies” and “Recent Trends in Computing”. The Chapter “Basic Internet Terminologies” equip the students with commonly used terms used while accessing internet whereas the second Chapter “Recent Trends in Computing” has been added with an objective to keep the students updated with recent technological developments in the fast changing digital space.

Chapter 7 “Decision Making with Excel” has also been thoroughly revised than earlier editions of the book based on feedback

received from the readers. The Chapter includes suggestive solutions for even complex business problems. The book aims to acquaint the commerce undergraduates with the information technology tools. The unique feature of this book is its simple presentation and step wise explanation that ensures that any student even without having a prior computer literacy can also learn computing and its business applications on his own.

We are extremely thankful to Dr. S.K. Sharma, Associate Professor, SGTB Khalsa College for contributing significant portion of Chapter DBMS Using MS Access 2010. His valuable suggestions and critical comments encouraged us to complete this book. We thankfully acknowledge the contributions made by Mr. Surender Kumar, Associate Professor, PGDAV College; Mr. Vikas Madan, Assistant Professor, SRCC and Mrs. Aruna Jain, Associate Professor, Bharti College in finalizing the book.

We also received great contributions and suggestions from Dr. Rajnikant Verma, Associate Professor, Zakir Husain Delhi College; Dr. Vibha Gupta Associate Professor, Laxmi Bai College; Ms. Sonal Thukral, Assistant Professor, DTU; Ms. Anju Verma and Ms. Anuradha Agarwal, SRCC; Dr. Prabhat Mittal, Associate Professor, Satyawati College (Evening); Dr. Rajiv Middha, Associate Professor, SGND Khalsa College; Shweta Sharda and Ms. Rekha, Assistant Professor, IP College; Dr. Geeta Siddharth, Associate Professor, Gargi College; Ms. Anjali Tuli, Assistant Professor, Hansraj College; Dr. Kalpana Devi and Ms. Chetan Kaur, Associate Professor, Mata Sundri College which we thankfully acknowledge.

We extend our heartiest thanks to Professor C.P. Gupta, Department of Financial Studies; Dr. S.K. Garg, Principal, DDU College, Dr. P.C. Jain, Former Principal, SRCC, Dr. R.P. Rustagi, former Acting Principal, SRCC; Dr. Anil Kumar, Associate Professor, SRCC and Mr. Narain, Assistant Professor, FMS for providing their constant encouragement and support throughout.

We are also grateful to our publisher “Taxmann”, for completing the book in time and always positively considering the changes suggested overtime.

Feedback from the readers is solicited and would be thankfully acknowledged.

Ne w Del hi, I ndi a

Dr. Hem Chand Jain Dece mber, 2022 he mc ha ndj ai n @ya hoo. c o. i n

Dr. Harendra Nath Tiwari ti wari har e nder @ya hoo. c o. i n

Syllabus

B.COM (HONS.): SEMESTER-IV PAPER BCH 4.3: COMPUTER APPLICATIONS IN BUSINESS

COURSE CONTENTS

UNIT 1

Data Processing, Networking and Recent trends in computing Computing : Co nce pt of c o mp uti ng, Dat a a nd i nf or mati o n; Co mp uti ng I nt erf aces: GUI, CLI, To uc h I nt erf ace, NLI; dat a pr ocessi ng; a ppli c ati o ns of c o mp ut ers i n b usi ness;

Computer Networks: Me a ni ng of c o mp ut er net wor k; o bj ecti ves / nee ds f or net wor ki ng; Appli c ati o ns of net wor ki ng; Basi c Net wor k Ter m i nol ogy; Ty pes of Net wor ks; Net wor k Topol ogi es; Di st ri b ut e d Co mp uti ng: Cli e nt Ser ver Co mp uti ng, Peer- t o- peer Co mp uti ng; W i r el ess Net wor ki ng; Sec uri ng Net wor ks: fir e wall.

Basic Internet Terminology: I. P . Addr ess, Mo de m , Ba nd w i dt h, Ro ut ers, Gat eways, I nt er net Ser vi ce Pr ovi der ( I SP), Worl d W i de We b ( www), Br o ws ers, Se ar c h Engi nes, Pr oxy Ser ver, I nt r a net a nd Ext r a net; Basi c I nt er net Ser vi ces; I nt er net Pr ot oc ol s: T CP/I P , F TP , HTTP( s), Us es of I nt er net t o Soci et y; Cy ber Sec uri t y: Cr y pt ogr a p hy, di gi t al si g nat ur e.

Recent trends in computing : Tool s of b usi ness c oll a bor ati o n: e- mail s, w i ki s, fil e s hari ng, s cr ee n s hari ng, we b pr es e nti ng, wor k s c he d uli ng; Cl o ud c o mp uti ng: me a ni ng, t y pes of cl o ud s er vi ces: I aa S , Paa S , Saa S ; Gri d Co mp uti ng; Vi rt ual - i z ati o n; Gr ee n Co mp uti ng; E- Co mmer ce: me a ni ng, b usi ness mo del s , El ect r o ni c Dat a I nt er c ha nge ( E DI), Pay me nt Gat e ways; I nt er net of Thi ngs ( I o T).

UNIT 2

Word Processing

I nt r o d ucti o n t o wor d Pr ocessi ng, Wor d pr ocessi ng c o nce pt s, Us e of Te mpl at es, Wor ki ng w i t h wor d doc u me nt: Edi ti ng t e xt, Fi nd a nd r e pl ace t e xt, For matti ng, s pell c hec k, Aut oc orr ect, Aut ot e xt; Bull et s a nd n u mberi ng, Ta bs, Par agr a p h For matti ng, I nde nt, Page For matti ng, Hea der a nd f oot er, Ta bl es: I ns erti ng, filli ng a nd f or matti ng a t a bl e; I ns erti ng Pi ct ur es a nd Vi de o; Mail Mer ge: i ncl udi ng li nki ng w i t h Dat a bas es a nd s pr e a ds heet fil es; Pri nti ng doc u me nt s; Ci t ati o ns a nd Foot not es.

Creating Business Documents using the above facilities

UNIT 3

Preparing Presentations

Basi cs of pr es e nt ati o ns: Sli des, Fo nt s, Dr a w i ng, Edi ti ng; I ns erti ng: Ta bl es, I mages, t e xt s, Sy mbol s, hy perli nki ng, Me di a; Desi g n; Tr a nsi ti o n; Ani mati o n; a nd Sli des ho w

Creating Business Presentations using above facilities

UNIT 4

Spreadsheet and its Business Applications

Spreadsheet concepts , Ma nagi ng wor ks heet s; For matti ng, c ondi ti onal f or mat - ti ng, Ent eri ng dat a, Edi ti ng, a nd Pri nti ng a nd Pr ot ecti ng wor ks heet s; Ha ndli ng oper at ors i n f or mul a, Pr oj ect i nv ol vi ng mul ti pl e s pr e a ds heet s, Or ga ni zi ng Chart s a nd gr a p hs; Wor ki ng w i t h Mul ti pl e wor ks heet s; c o nt r olli ng wor ks heet vi e ws, na m i ng cell s a nd cell r a nges.

Spreadsheet functions: Mat he mati c al, St ati sti c al, Fi na nci al, Logi c al, Dat e a nd Ti me, Look up a nd r ef er e nce, Dat a bas e f uncti o ns, Te xt f uncti o ns a nd Err or f uncti o ns.

Working with Data: Sort a nd fil t er; Co ns oli dat e; Ta bl es; Pi v ot t a bl es; Whati f- a nal ysi s: Goal s ee k, Dat a t a bl es a nd Sce nari o ma nager; Dat a a nal ysi s Tool Pa k: Des cri pti ve St ati sti cs, Movi ng aver ages, H i st ogr a m , Covari a nce, c orr el ati o n a nd Re gr essi o n a nal ysi s ( o nl y f or pr oj ecti o n).

Creating business spreadsheet: Loa n a nd Le as e st at e me nt; Rati o Anal ysi s; Payr oll st at e me nt s; Ca pi t al Budgeti ng; Co nst r ai nt opti m i z ati o n, Assi g n me nt Pr obl e ms, De pr eci ati on Acc o unti ng; Gr aphi cal r e pr es e nt ati on of dat a; Fr e q ue ncy di st ri b uti o n a ndi t s st ati sti c al par a met ers; Corr el ati o n a nd Re gr essi o n Anal ysi s.

UNIT 5

Database Management System (Theory)

Theoretical background of Database Designs for Accounting and Business Applications: Dat a bas e, Dat a bas e Ma nage me nt Syst e m , Dat a bas e Syst e m ; Co mpari s o n of Dat a bas e Syst e m w i t h Tr a di ti o nal Fil e Syst e m ; Enti t y Rel ati o ns hi p Mo del ( E R- Mo del ); Rel ati o nal Dat a bas e Mo del: Cr e ati ng Rel ati o ns hi p bet wee n Ta bl es, Co nce pt of Ke ys, Funda me nt al I nt e gri t y Rul es; E RD t o Rel ati o nal Ma ppi ng; Nor mali z ati o n of dat a bas es upt o 3 Nor mal For ms

SQL and Retrieval of Information: Basi c Queri es i n S QL ; E mbe dde d Queri es i n S QL ; I ns ert, Del et e a nd Up dat e st at e me nt s i n S QL

DBMS Software: Envi r o n me nt; Ta bl es; For ms; Queri es; Re port s; Mo d ul es; Appl yi ng DB MSi n t he ar e as of Acc o unti ng, I nve nt or y, HR Ma ndi t s acc o unti ng, Ma nagi ng t he dat a r ecor ds of E mpl oyees, Suppli ers and Cust o mers.

CHAPTER 1 : BASI C C O MP UT E R C ONCEP TS A ND NET WORKI NG 1

CHAPTER 2 : BASI C I NT E RNET T E R MI NOL OGI ES 55

CHAPTER 3 : RECE NT T RE NDS I N C O MP UTI NG 85 CHAPTER 4 : MI C ROS OF T WORD 2010 101 CHAPTER 5 : BASI CS OF P O WE RP OI NT 156 CHAPTER 6 : MS E XCEL 2010 177 CHAPTER 7 : E XCEL F UNCTI ONS 218 CHAPTER 8 : DECI SI ON MA KI NG W I T H E XCEL 282

CHAPTER 9 : E XCEL P ROJ ECTS 334 CHAPTER 10 : I NT RODUCTI ON T O DATABAS E S YS T E M 418 CHAPTER 11 : MA NA GI NG DATABAS ES USI NG MS ACCESS 458

PAGE

Preface to Seventh Edition I-5 Syllabus I-9 Chapter-heads I-13 1

BASIC COMPUTER CONCEPTS AND NETWORKING

1.1 Introduction 1

1.2 Meaning of computers 2

1.3 A brief history 3

1.4 Hardware 5

1.5 Functional units of a computer 13

1.6 Characteristics of a computer 16

1.7 Advantages of the computers 17

1.8 Uses of computers 18

1.9 Limitations of computers 20

1.10 Concepts of computing, data and information 20

1.11 Some commonly used computing interfaces 22

1.12 Computer networks 23 1.13 Applications of networking 25 1.14 Basic networking terminology 26 1.15 Types of network 31 1.16 Network topologies 34 1.17 Distributed computing system 42 1.18 Wireless networking 48 1.19 Summary 51 1.20 Review questions 52 2

BASIC INTERNET TERMINOLOGIES

2.1 Introduction 55

2.2 Meaning of internet 56

2.3 A brief history 56

2.4 Basic internet terminologies 57

2.5 How to get connected to internet ? 70

2.6 Basic internet services 72

2.7 Internet protocols 74

2.8 Uses of internet to society 76

2.9 Search engine 77

2.10 Cyber security 78 2.11 Summary 81

2.12 Review questions 82 I-15

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3

RECENT TRENDS IN COMPUTING

3.1 Business collaborations 85

3.2 Cloud computing 88

3.3 Grid computing 90 3.4 Virtualization 91 3.5 Green computing 91

3.6 E-commerce 92 3.7 Internet of things (IOT) 98 3.8 Summary 99 3.9 Review questions 100

4

MICROSOFT WORD 2010 5

4.1 Introduction 101 4.2 The ribbon 102 6

4.3 Review questions 152

BASICS OF POWERPOINT

5.1 Introduction 156 5.2 How to create a presentation using powerpoint 157 5.3 Design ribbon toolbar 158 5.4 Formatting a presentation – Inserting table, smart art, chart & pictures 160 5.5 Applying themes 160 5.6 Adding a new slide 162 5.7 Applying transitions & animations 162

5.8 Adding sound & video to your presentation 166 5.9 Adding a hyperlink to your presentation 169 5.10 Presenting a slide show 170 5.11 Effective presentation skills 171 5.12 Printing slides 172 5.13 How to upload Powerpoint to youtube 173 5.14 Summary 174 5.15 Review questions 175

MS EXCEL 2010

6.1 Introduction 177 6.2 Excel 2010 environment 177 6.3 Saving workbooks 180

6.4 Worksheet basics 181 6.5 Printing 183 6.6 The cell 186

TAXMANN®

ONTE NTS

6.7 Modifying columns, rows and cells 188

6.8 Formatting cells 190

6.9 Sorting data 192

6.10 Charts 196

6.11 Creating simple formulas 203 6.12 Complex formulas 205 6.13 Working with basic functions 209 8

7

9

EXCEL PROJECTS

8.4 Pivot table 304 8.5 Capital budgeting 311 8.6 Ratio analysis 317 8.7 Other excel applications 322 9.1 Payroll accounting 334 9.2 Loan and lease accounting 359 9.3 Depreciation 373 PAGE

DECISION MAKING WITH EXCEL 10

9.4 Statistical 389 9.5 Unsolved questions 406

INTRODUCTION TO DATABASE SYSTEM

10.4 Traditional file system vs. Database system 424 10.5 Evolution of database management technology 425

C ONTE NTS I-18 PAGE

10.6 Modern approach of database 426

10.7 Summary 455

10.8 Review questions 456

11

MANAGING DATABASES USING MS ACCESS

11.1 Introduction 458

11.2 Objects in MS access 2010 459

11.3 Creating database 460

11.4 Understanding MS access window 461

11.5 Creating tables 462

11.6 Implementing relationship between the tables 477

11.7 Creating queries 480 11.8 Queries using SQL 497 11.9 Forms using form wizard 508 11.10 Preparing reports using report wizard 517 11.11 Application of MS access in the field of accounting 536 11.12 Review questions 570

12

MAIL MERGE

12.1 Introduction 578

12.2 Steps to use mail merge 579

12.3 Mail merge using database of MS access 2010 590

12.4 Mail merge using database in MS excel 2010 597 12.5 Review questions 599 u B.COM (HONS.)/SEM. IV-2017 603 u B.COM (HONS.)/SEM. IV-2018 604 u B.COM (HONS.)/SEM. IV-2019 605 u MODEL PAPER-1 607 u MODEL PAPER-2 611 u MODEL PAPER-3 614 u MODEL PAPER-4 618

BASIC COMPUTER CONCEPTS AND NETWORKING

CHAPTER PLAN

I nt r o ducti o n 1.2 Mea ni ng of Co mp ut ers 1.3 A bri ef hi st or y 1.4 I np ut - Out p ut Devi ces 1.5 Functi o nal Co mpo ne nt s of a Co mp ut er 1.6 Char act eri sti cs of t he c o mp ut er 1.7 Adva nt ages of t he Co mp ut er 1.8 Us es of t he Co mp ut er 1.9 Li m i t ati o ns of Co mp ut er 1.10 Co nce pt s of c o mp uti ng, dat a a nd i nf or mati o n

1.1

1.1 INTRODUCTION

1.11

So me Co mmo nl y us e d Co mp uti ng I nt erf aces 1.12 Co mp ut er Net wor ks 1.13 Appli cati o ns of net wor ki ng 1.14 Basi c Net wor ki ng Ter m i nol ogy 1.15 Ty pes of Net wor ks 1.16 Net wor k Topol ogi es 1.17 Di st ri but e d Co mp uti ng Syst e m 1.18 W i r el ess Net wor ki ng 1.19 Su mmar y 1.20 Revi e w Questi o ns

I n t he age of mac hi nes c o mp ut er i s t he gr e at est i nve nti o n of me n. It has pave d ways f or ma ny ot her i nve nti o ns. The i de a of havi ng a c o mp ut er be ga n w i t h t he pe opl e who wa nt e d e asi er way t o s ol ve t he c al c ul ati o n pr o bl e ms. But, no wt he c o mp ut ers ar e not o nl y us e d f or t he p ur pos e of c o mp ut ati o n r at her t he y have e nt er e d o ur day t o day li f e i n s uc h a ma nner t hat we c a nnot t hi nk of li vi ng w i t ho ut t he m The c o mp ut ers ar e us e d i n a vari et y of ways i n t e ac hi ng a nd r es e ar c h a ndi n t he c o mmuni c ati o n s yst e m . The mo der n c o mp ut er t hat we us e

no w- a- days has pass e d t hr o ug h vari o us st ages of e v ol uti o n bef or e c o m i ng i ni t s pr es e nt f or m The pr es e nt c ha pt er i s ai me d t o di s c uss t he p has es of e v ol uti o n, c har act eri sti cs a nd a dva nt ages of c o mp ut ers t o h u ma n bei ngs. Furt her, t he wor ki ng s yst e m of t he c o mp ut ers a nd n u mber s yst e m ar e al s o di s c uss e d t o k no w t he f uncti o nali t y of t he c o mp ut ers i n t hi s c ha pt er.

1.2 MEANING OF COMPUTERS

The c o mp ut er i s a ge ner al p ur pos e el ect r o ni c de vi ce pr ogr a mme d t o pr ocess dat a a nd t o c o nvert i t i nt oi nf or mati o n. It i s a pr ogr a mma bl e el ect r o ni c mac hi ne whi c h perf or ms hi g h s pee d mat he mati c al or l ogi c al oper ati o ns. It i s al s o pr ogr a mme d t o st or e, r et ri e ve a nd c orr el at e t he i nf or mati o n. It i s a c o mposi ti o n of har d war e a nd s oft war e t hat c a n e xi st i n a vari et y of si z es a nd c o nfi g ur ati o ns. A c o mp ut er c o nsi st s of ma ny el ect r o ni c c o mpo ne nt s or part s, e ac h o ne havi ng a s peci al r ol e t o perf or m . So me c o mpo ne nt s ar e hi dde n i nsi de t he c o mp ut er, wher e as s o me of t he m ar e vi si bl e f r o m o ut si de.

I nsi de a c o mp ut er t her e i s a motherboard whi c h g et s i t s na me bec a us e i t i s li ke a mot her t o all of t he ot her ci r c ui t boar ds. Thi s i s t he mai n ci r c ui t boar d whi c h c o nnect s all of t he ot her i nt er nal c o mpo ne nt s.

The CP U a nd t he me mor y ar e us uall y pl ace d o n t he mot her - boar d. Ot her s yst e ms may be o n t he mot her boar d or may be c o nnect e d t o i t t hr o ug h s o me s ec o ndar y c o nnecti o n

For e x a mpl e, a s o u n d c ar d c a n be b uil t o nt o t he mot her boar d or c o nnect e d t hr o ug h P CI ( Peri p her al Co mpo ne nt I nt erf ace).

The c o mp ut er, a n el ect r o ni c de vi ce, has t o acce pt dat a a nd pr ocess es t he dat a acc or di ng t o t he pr ogr a m a nd pr o d uces t he o ut p ut. For all t hi s t he c o mp ut er nee ds t wo t y pes of i np ut o ne i n t he f or mof dat a t o be pr ocess e d a nd ot her i n t he f or mof t he s et of i nst r ucti o ns ( al s o c all e d c o mp ut er pr ogr a m ) t o pr ocess or act upo n t he dat a The c o mp ut er i s us e d as a dat a pr ocess or a nd i t i s pr ogr a mme d t o ha ndl e t he dat a whi c h may var y i n si z e a nd st r uct ur e. Sc he mati c all y t hi s pr ocess i s s ho wn i n fi g ur e 1. 2.

FIGURE 1.1 : MOTHERBOARD

Dat

a I nst r ucti o ns

Pr ocess Out p ut I np ut

FIGURE 1.1 : DATA PROCESSING

The vari o us i np ut a nd o ut p ut de vi ces us e d d uri ng t he pr ocess ar e di s c uss e d i n t he c o m i ng uni t s.

1.3 A BRIEF HISTORY

Ar o u n d 4t h c e nt ur y B C a si mpl e c o unti ng ai d was i nve nt e d i n Ba byl o ni a ( no w I r a q) na me d Abacus ( Fi g. 1. 3). It was a wo o de n r ac k hol di ng t wo hori z o nt al w i r es w i t h be a ds st r ung o n t he m . Nu mbers wer e r e pr es e nt e d usi ng t he posi ti on of be a ds o n t he r ac k. The si mpl e cal c ul ati ons wer e carri e d o ut by appr opri at el y pl aci ng t he bea ds. I n 1642, a Fr e nc h mat he mati ci a n a nd p hil os op her Bl ai s e Pas c al i nve nt e d a c al c ul ati ng de vi ce na me d “ Addi ng Mac hi ne” ( Fi g. 1. 4). It was a n i mpr oveme nt over Abac us It i s al s o k no wn as “ Nu meri c al Wheel Cal c ul at or” It uti - li z e d a t r ai n of 8 mova bl e di al s t o a dd s u ms of upt o 8 fi g ur es l o ng. As o ne di al t ur ne d c o mpl et e r e v ol u - ti oni t mec ha ni call y t ur ne d t he ne xt di al. It pr ovi de d a f ai r de gr ee of acc ur ac y a nd s pee d.

FIGURE 1.4 : ADDING MACHINE

FIGURE 1.3 : ABACUS

The fi rst a ut o mat e d c o mp ut er was i n v e nt e d b y

Charles Babbage , a pr o - f ess or of mat he mati cs at

Ca mbri dge Uni versi t y, Engl a nd, i n 1822. He r eali z e dt hat ma nyl ong cal c ul ati ons us uall y c o nsi st e d of a s eri es of acti o ns whi c h wer e c o nst a ntl y r e pe at e d a nd he nce c o ul d possi bl y be a ut o mat e d. He pers ua de d t he Bri ti s h g over n me nt t o fi na nce hi s desi g n t o b uil d a mac hi ne t hat wo ul d c al c ul at e t a bl es f or l ogari t h ms . He desi g ne d a n a ut o mati c c al c ul ati ng mac hi ne t hat he c all e d t he ‘ Difference

Engine ’ . It was st e a m po wer e d a nd f ull y a ut o mat e d. For hi s c o nt ri b uti o ns i n t he fi el d, Charl es Ba bbage i s al s o k no wn as father of computers. The e v ol uti o n of c o mp ut ers c a n be di vi de d i nt o 5 ge ner ati o ns:

1. Fi rst Ge ner ati o n ( 1940- 1956) : Vac uu m Tubes

2. Sec o nd Ge ner ati o n ( 1957- 1963) : Tr a nsi st ors

3. Thi r d Ge ner ati o n ( 1964- 1971) : I nt e gr at e d Ci r c ui t s ( I Cs )

4. Fo urt h Ge ner ati o n ( 1971- Pr es e nt) : M i cr opr ocess ors

5. Fi ft h Ge ner ati o n ( Pr es e nt a nd Be y o nd) : Arti fi ci al I nt elli ge nce

First Generation (1940-1956): Use of Vacuum Tubes

The c o mp ut ers ma de a nd us e d d uri ng t he ye ars 1940 t o 1956 ar e beli e ve d t o be t he fi rst ge ner ati o n of c o mp ut ers whi c h us e d vac uu m t ubes f or ci r c ui t r y a nd mag neti c dr u ms f or me mor y. The si z e of fi rst ge ner ati o n c o mp ut ers was oft e n e nor mo us, t a ki ng up t he e nti r e r oo m . The y wer e ver y e x pe nsi ve t o oper at e a nd i n a ddi ti o n us e d a gr e at de al of el ect ri ci t y, ge ner at e d a l ot of he at, whi c h was oft e n t he c a us e of mal f uncti o ns. The fi rst ge ner ati o n c o mp ut ers r eli e d o n mac hi ne l a ng uage, t he l o west pr ogr a mm i ng l a ng uage, pr ogr a mme d i n st ri ngs of ‘ 0’ s a nd ‘ 1’ s It was ver y di ffi c ul t t o t r ace a nd c orr ect t he pr ogr a mm i ng err ors, i f a ny. The e xa mpl es of fi rst ge ner ati o n c o mp ut ers ar e UNI VAC a nd E NI AC .

Second Generation (1957-1963): Use of Transistor

The s ec o nd ge ner ati o n c o mp ut ers us e d Tr a nsi st ors i n pl ace of vac uu mt ubes. The t r a nsi st or was i nve nt e d i n 1947 b ut i t was us e d i n c o mp ut ers i n o nl y l at e 1950’ s. The t r a nsi st or was s uperi or t o t he vac uu m t ube i n t he s e ns e t hat i t ma de c o mp ut ers s mall er, f ast er, c he a per a nd mor e e ner gy- effi ci e nt It di dn’ t r e q ui r e a c o mpl et e r oo m a ny mor e. Ho we ver, e ve n t ho ug h i t was a n i mpr oveme nt over t he vac uu mt ube t he t r a nsi st or still ge ner at e d a gr e at de al of he at whi c h s o meti me s ubj ect e d t he c o mp ut er t o da mage i t s i nt er nal s e nsi ti ve part s. Sec o nd- ge ner ati o n c o mp ut ers us e d ass e mbl y l a ng uage f or pr ogr a mm i ng. So me e arl y versi o ns of C OB OL a nd F ORT RA N wer e al s o us e d by t he s ec o nd ge ner ati o n c o mp ut ers.

Third Generation (1964-1971): Use of Integrated Circuits

I n 1958, t he de vel op me nt of t he i nt e gr at e d ci r c ui t ( I C) t ook pl ace b ut i t c o ul d be us e di n c o mp ut ers o nl y aft er m i d of 1960s whi c h br o ug ht si g ni fi c a nt c ha nge i n c o mp uti ng. I Cs us e d sili c o n c hi ps, c all e d s e m i c o nd uct ors, whi c h dr asti c all y i ncr e as e d t he s pee d a nd effi ci e nc y of c o mp ut ers. As a r es ul t, t he c o mp ut ers bec a me s mall er i n si z e as mor e c o mpo ne nt s wer e s q ueez e d o nt o t he c hi p.

Anot her si g ni fi c a nt de vel op me nt i n t hi r d- ge ner ati o n c o mp ut ers i ncl ude d t he us e of a n oper ati ng s yst e m whi c h all o we d mac hi nes t o r un ma ny di ff er e nt pr ogr a ms at o nce w i t h a ce nt r al pr ogr a m whi c h mo ni t or e d a nd c o- or di nat e d t he c o mp ut er ’ s me mor y.

Fourth Generation (1971-Present): Use of Microprocessors

The f o urt h ge ner ati o n c o mp ut ers c a n be c har act eri z e d by t he us e of m i cr opr ocess ors, a si ngl e sili c o n c hi p o n whi c h t ho us a nds of i nt e gr at e d ci r c ui t s wer e b uil t The us e of M i cr opr ocess ors c o nsi der a bl y r e d uce d t he si z e No w c o mp ut ers fi t i n t he pal m of t he ha nd. The pers o nal c o mp ut ers a nd l a pt ops all ma de us e of m i cr opr ocess ors

For t he fi rst ti me i n 1981, I B Mi nt r o d uce d c o mp ut ers f or t he ho me us ers, a nd i n 1984 Appl e i nt r o d uce d t he Maci nt os h The f o urt h ge ner ati o n c o mp ut ers bec a me ver y po werf ul, no w t he y c o ul d be li nke d t oget her t o f or m a net wor k. The l a pt ops, ho me P C ’ s, pal mt ops, mo bil e p ho nes all c a n be att ri b ut e d t o f o urt h ge ner ati o n c o mp ut ers t hat we us e t o day.

Fifth Generation (Present and Beyond): Artificial Intelligence

Thi s c at e g ori z ati o n of c o mp ut er ge ner ati o ns i s bas e d upo n t he us e of arti fi ci al i nt elli ge nce. It i s still i n t he de vel op me nt p has e. Ho we ver, s o me r o bot s have bee n de vel ope d whi c h ar e hel pi ng i n me di c al s ci e nce a nd r es e ar c h. So me of t he c o mp ut er a ppli c ati o ns li ke v oi ce r ec og ni ti o n, t e xt t o s peec h a nd s peec h t o t e xt c a n be att ri b ut e d t o fi ft h ge ner ati o n c o mp ut ers. The movi es li ke Ter m i nat or s eri es ( 1, 2 a nd 3) a nd Ro bot ar e bas e d o n t he c o nce pt of fi ft h ge ner ati o n c o mp ut ers.

1.4 HARDWARE

1.4.1 Input Devices

An i np ut de vi ce i s a peri p her al de vi ce whi c h acce pt s dat a or c o mma nds a nd s e nds i t t o t he CP U . Ther e ar e di ff er e nt t y pes of dat a t o be s e nt t o CP U . De pe ndi ng upo n t he dat a t y pe t he i np ut de vi ces ar e us e d. For e xa mpl e barc o de r e a der i s us e d t o t he r e a d bar- c o des.

The i np ut de vi ces ar e us e d t o c o nvert t he dat a o bt ai ne d i nt o t he l a ng uage whi c h c o mp ut er underst a nds i. e. c o mp ut er ’ s o wni nt er nal c o de bef or e s e ndi ng i t t o t he CP U .

So me of t he I np ut de vi ces ar e e x pl ai ne d as f oll o ws:

Keyboard i s t he most c o mmo nl y us e d i np ut de vi c e t hat c o nvert s al p ha bet s, n u mbers, a nd ot her s peci al c har act ers i nt o el ect ri c al p ul s es whi c h c a n be un -

derst oo d by t he c o mp ut ers. The most pop ul ar ke y boar d us e d t o day i s t he 101- ke ys Q WE RT Y ke y boar d, c all e d as t he st a ndar d ke y boar d The t y pes of ke ys o n a ke y boar d ar e:

– Nu meri c / Di gi t ke ys e g 1, 2, 3, 4

– Al p ha beti c ke ys / Lett er ke ys e. g. A , B , C , D a nd s o o n. Ther e ar e 26 l ett ers of Engli s h al p ha bet

– Functi o n ke ys e. g. F1, F2, F3, F4 a nd s o o n.

– Punct uati o n ke ys e. g. :, ; , (),’

– Speci al c har act er ke ys e g < , > , ?, × , |, \, @ , #, ^ et c Most of t hes e ke ys ar e pri nt e d whe n us e d al o ng w i t h t he Shi ft ke y.

– No n- pri nt a bl e c o nt r ol ke ys e g Ent er / Ret ur n ke y, Space ke y, Ca ps Loc k, Shi ft ke y, arr o w ke ys, Ta b ke y ( moves c urs or t o t he ne xt t a b st op), Del et e ke y.

Mouse

i s a s mall ha nd hel d de vi ce whi c h i s us e d t o i ndi c at e a posi ti o n or move me nt o n a c o mp ut er ’ s di s pl ay s cr ee n by r olli ng i t over a mo us e pa d. Mo us e e nt ers dat ai n t wo di ff er e nt ways. Fi rstl y, as t he mo us e i s move d, a ball under ne at h i t or a l as er be a mli g ht r e v ol ves a nd t hi s move me nt i s det ect e d by s e ns ors whi c h s e nd t he dat a t o t he CP U . Sec o ndl y, a mo us e ge ner all y has a l eft cli c k b utt o n a nd a ri g ht cli c k b utt o n.

A mo us e i s of 3 t y pes: Mec ha ni c al mo us e, Opti c al mo us e a nd Opt o mec ha ni c al mo us e. Al s o t he y c a n be cl assi fi e d i n t er ms of c o nnecti vi t y t o t he c o mp ut er li ke w i r e d a nd w i r el ess mo us e.

Track Ball : At r ac k ball has a ball o n t op t hat c a n r ot at e f r eel y. I nst e a d of movi ng t he de vi ce li ke a mo us e, o ne c a n si mpl y r oll t he ball w i t h t he fi ngers t o move t he poi nt er.

Touchpad:

A t o uc hpa d ( or t r ac kpa d) i s a poi nti ng de vi ce t hat c a n t r a nsl at e t he moti o n a nd posi ti o n of a us er ’ s fi ngers t o a r el - ati ve posi ti o n o n s cr ee n To uc hpa ds ar e a c o mmo n f e at ur e of l a pt op, not e book c o mp ut ers.

Joystick: Aj oysti c k c o nsi st s of a s mall l e ver whi c h i s move d by t he us er t o c o nt r ol move me nt o n a s cr ee n I n t hi s c as e al s o s e ns ors det ect t he move me nt of t he l e ver a nd s e nd t he c orr es po ndi ng dat a t o t he CP U .

Thes e ar e ge ner all y us e d f or pl ayi ng vi de o ga mes.

Light Pen: It i s a poi nti ng de vi ce t hat utili z es a li g ht- s e nsi ti ve det ect or t o s el ect o bj ect s o n a di s pl ay s cr ee n It i s si mil ar t o a mo us e, e xce pt t hat w i t h a li g ht pe n y o u c a n move t he poi nt er a nd s el ect o b - j ect s o n t he di s pl ay s cr ee n by di r ectl y poi nti ng t o t he o bj ect s w i t h t he pe n.

Touch Screen: I t i s s peci all y desi g ne d vi de o di s pl ay s cr ee n t hat has t he c a pa bili t y t o r ecei ve i np ut f r o mt he t o uc h of a fi nger.

Digitizing Tablet: Di gi t i z i n g Ta bl e t / D i gi ti z ers r ef ers t o a n el ect r oni c pl asti c boar d on whi c h s peci f yi ng a l ocati on c orr es ponds t ol ocati on on t he c o mp ut er s cr ee n . Thes e ar e us e d by ar c hi t ect s a nd e ngi neers i n Co mp ut er Ai de d Desi g ni ng ( CA D) f or desi g ni ng p ur pos es.

Bar Code Readers: Bar Code Reader (BCR) i s a p hot o el ect ri c s c a nner t hat t r a nsl at es t he bar c o des i nt o di gi t al c o de. Bar Codes ar e s peci al i de nti fi cati on c odes pri nt e d as a s et of verti cal st ri ppe d mar ks of di ff er e nt w i dt h us uall y s ee n o n ma n uf act ur e d r et ail pr o d uct s The bar c o de i de nti fi es t he pr o d uct t o t he s uper mar ket’ s c o mp ut er, whi c h has a des cri pti o ns a nd t he l at est pri ce of t he pr o d uct.

Optical Character Recognition (OCR): It i s t he el ect r o ni c t r a nsl ati o n of pri nt e d i mages or n u mer al s, l ett ers or s y mbol s whi c h may be ha nd wri tt e n or t y pe d i nt o di gi t al c o de. It i nvol ves t r a nsl ati ng t he t ext f r o mpaper i nt o a f or mt hat t he c o mp ut er c a n ma ni p ul at e a nd f ee d i t di r ectl y i nt o c o mp ut er fil e. It i s w i del y us e d t o c o nvert books a nd doc u me nt s i nt o el ect r o ni c fil es.

Optical Mark Reader (OMR): It r ef ers t o a de vi ce t hat r e a ds pe ncil mar ks a nd c o nvert s t he mi nt o a f or m t hat c a n be pr ocess e d by a c o mp ut er.

Magnetic Ink Character Reader (MICR): MI C R i s a c har act er r ec og ni ti o n t ec hnol ogy us e d pri maril y by t he ba nki ng i nd ust r y t o f acili t at e t he pr ocessi ng of c he q ues. It c o nsi st s of s peci al i nk c all e d mag neti c i nk t hat i s us e d t o wri t e c har act ers o n t he c hec k a nd de posi t f or ms t o be pr ocess e d by a n MI C R .

Microphone: M i cr op ho ne i s a v oi ce r ec og ni ti o n de vi ce t hat c o nvert s a udi o si g nal s t o el ect ri c al waves a nd t hes e c a n be c o nvert e d by el ect r o ni c ci r c ui t r y i n t he c o mp ut er t o di gi t al f r o m . The us er c a n si mpl y i nst r uct t he c o mp ut er a bo ut t he t as k t o be perf or me d w i t h t he hel p of a m i cr op ho ne. It c a n be us e d t o r ec or d s o und or t o c o mmuni c at e w i t h a not her c o mp ut er us er vi a t he I nt er net Ma ny c o mp ut ers c o me w i t h b uil t-i n m i cr op ho nes.

Digital Camera: Di gi t al c a mer as all o wt o t a ke di gi t al p hot ogr a p hs The i mages ar e st or e d o n a me mor y c hi p or di s k t hat c a n be t r a nsf err e d t o t he c o mp ut er.

Web Camera: A we bc a m or we b c a mer a i s a c a mer a t hat ge ner at es i mages t hat c a n be access e d o n t he I nt er net. Ma ny pe opl e us e we bc a ms f or c hatti ng, vi de o c o nf er e nci ng et c We bc a mall o ws us er t o t a ke i mages f r o mt he c o mp ut er a nd c o mmuni c at e vi s uall y w i t h ot her us ers o n t he I nt er net.

Scanner/Image Scanner: It i s a de vi ce t hat c o nvert s p hot os, dr a w i ngs, gr a p hi cs a nd t e xt i nt o di gi t al f or m as i np ut t o t he c o mp ut er. It hel ps i n pr es er vi ng pa per doc u me nt s i n el ect r o ni c f or ms o t hat i t does not det eri or at e w i t h age a nd c a n be di s pl aye d or pri nt e d whe ne ver r e q ui r e d. It st or es t he doc u me nt as i mage. Thes e st or e d i mages c a n be al t er e d a nd ma ni p ul at e d i n i nt er esti ng ways i f t he c o mp ut er has i mage- pr ocessi ng s oft war e. Ther e ar e 2 t y pes of i mage s c a nners:

(a) Hand-held scanners: Thes e s c a nners ar e hel d i n ha nd t o s c a n a n i mage or doc u me nt by movi ng i t over t he o bj ect Thes e ar e port a bl e

(b) Flat-bed scanners: Thes e s c a nners have a fl at gl ass s urf ace wher e t he doc u me nt i s pl ace d j ust li ke i n a Xer ox c opi er The li d of t he s c a nner i s cl os e d bef or e gi vi ng t he c o mma nd f or s c a nni ng.

Fl at- be d

Ha nd- hel d

Fl at- be d s c a nners ar e t he c o mmo nl y us e d s c a nners i n e ver y day li f e.

1.4.2 Output devices

Out p ut de vi ces ar e us e d t o c o nvert t he mac hi ne c o des r ecei ve d f r o mt he CP U i nt o a f or m whi c h c a n be underst oo d by t he us ers i e h u ma ns The o ut p ut ge ner at e d by o ut p ut de vi ces may be of 2 t y pes:

1 Soft c opy o ut p ut

2. Har d c opy o ut p ut A f e w of t he o ut p ut de vi ces ar e di s c uss e d bel o w :

Monitor: A mo ni t or i s a di s pl ay de vi ce whi c h s ho ws t he dat a r ecei ve d f r o m c o mp ut er i n r e a da bl e a nd underst a nda bl e f or mt o t he us ers i. e. h u ma n, o nt o a vi de o s cr ee n. Mo ni t ors var y gr e atl y i n si z e a nd i n r es ol uti o n ( cl ari t y of gr a p hi cs). Ther e ar e 3 c o mmo n t y pes of mo ni t or:

VGA ( Vi de o Gr a p hi cs Arr ay): 640 × 400 pi xel s

S VGA ( Super Vi de o Gr a p hi cs Arr ay): 800 × 600 pi xel s.

E V GA or X V GA ( Ext e n de d Vi de o Gr a p hi cs Arr ay): 1024 × 768 pi xel s.

Para 1.4

The fi rst c o mp ut er mo ni t ors us e d c at ho de r ay t ubes ( C RT). Mo der n mo ni t ors us e li q ui d cr yst al di s pl ay ( TF T- L C D) or Li g ht E m i tti ng Di o de ( L E D) di s pl ay The mai n a dva nt ages of L C Ds over C RT di s pl ays ar e t hat L C Ds c o ns u me l ess po wer, t a ke up muc h l ess s pace, ar e c o nsi der a bl y li g ht er, a nd r e d uces e ye st r ai n. Thin film transistor liquid crystal display (TFT-LCD ) i s a vari a nt of li q ui d cr yst al di s pl ay i mpr oves i mage q uali t y. The q uali t y of mo ni t or de pe nds upo n:

(i) Resolution : It r ef ers t o t he n u mber of pi xel s i n a uni t s q ar e a It s ho ws t he s har pness a nd cl ari t y of i mage. Mor e t he r es ol uti on, hi g her t he q uali t y of mo ni t ors

(ii) Refresh rate : It r ef ers t o t he n u mber of ti mes t he mo ni t or i s r ef r es he d i n a uni t s ec o nd It i s me as ur e d i n hert z

(iii) Dot pitch : It r ef ers t o t he di st a nce bet wee n 2 pi xel s. At ti mes mo ni t ors al s o act as i np ut de vi ces e. g. us e of t o uc h s cr ee n mo ni t ors.

PRINTERS

Pri nt ers ar e us e d t o pri nt t he o ut p ut dat a o n a pa per. Suc h o ut p ut i s r ef err e d t o as pri nt o ut or har d c opy.

Types of Printers

Impact Printers

I mpact pri nt ers r ef er t o t hos e pri nt ers wher e t e xt or i mage i s pri nt e d by st ri ki ng ha mmers or pi ns agai nst a ri bbo n Thes e pri nt ers have mec ha ni s m si mil ar t o a t y pe wri t er. Thes e pri nt ers ar e no w dr yi ng o ut a nd ar e bei ng r e pl ace d by t he no n-i mpact pri nt ers. Thes e ar e of t wo t y pes.

Character Printer

Onl y o ne c har act er at a ti me i s pri nt e d It has r el ati vel y sl o wer s pee d E g Dot Mat ri x Pri nt er.

Line Printer

Thes e pri nt ers ar e capa bl e of pri nti ng a n e nti r e li ne at one ti me. A f ast li ne pri nter ca n pri nt as ma ny as 3, 000 li nes per m i nut e. The di s a dva nt ages of t hes e ar e t hat t hey ca nnot pri nt gr aphi cs, t he pri nt q uali t y i s l o w , a nd t hey ar e ver y noi s y.

Non-Impact Printers

No n- I mpact pri nt ers ar e us e d al most e ver y wher e no w . Thes e ar e f ast er a nd q ui et er t ha ni mpact pri nt ers. Thes e pri nt ers pr ovi de bett er q uali t y of o ut p ut. T wo t y pes of no n-i mpact pri nt ers oft e n us e d ar e l as er pri nt ers a nd i nk-j et pri nt ers.

Character Printer: It pri nt s o nl y o ne c har act er at a ti me. It has r el ati vel y sl o wer s pee d. E . g. Dot mat ri x pri nt er

Pri nt er

I mpact

Char act er Pri nt erDot Mat ri x

Dot Matrix Printer

Li ne Pri nt er

No n- I mpact

Char act er Pri nt er- I nk- J et

Page Pri nt er Las er

Dot mat ri x pri nt er i s ver y pop ul ar pri nt er. It pri nt s t he t e xt a nd gr a p hi cs w i t h t he hel p of a n arr ay of met al pi ns whi c h i s k no wn as pri nt he a d Thi s pri nt he a d st ri kes a n i nke d ri bbo n t o pri nt dot s o n t he pa per whi c h f or ms t he c har act er o n t he pa per as a r es ul t o ne c har act er i s pri nt e d at a ti me i n t hi s ki nd of pri nter. The q uali t y of pri nt de pe nds o n t he n u mber of pi ns us e d i n t he pri nt he a d, whi c h may var y f r o m9 t o 24. Dot- mat ri x pri nt ers pri nt a bo ut 50- 500 c har act ers per s ec o nd ( c ps).

Laser Printer

Thi s t y pe of pri nt er us es l as er be a mt o pr o d uce t e xt or i mage o n dr u m . Whe n t he l as er li g ht hi t s t he dr u m , t he n li g ht mo di fi es t he el ect ri c al c har ge o n t he dr u m . A r es er v oi r of t o ner t he n r oll s t he dr u m , whi c h i s pi c ke d up by t he c har ge d porti o ns of t he dr u m . Aft er t hat, t he c o mbi nati o n of he at a nd pr ess ur e t r a nsf ers t he t o ner t o t he pa per.

Copy mac hi nes, al s o wor ki n t he s a me way Las er pri nt ers ar e s o meti mes c all e d page pri nt ers. It s s pee d r a nges f r o m a bo ut 4 t o 20 pages of t e xt per m i n ut e ( pp m). A t y pi c al r at e of 6 pp mi s e q ui val e nt t o a bo ut 40 c har act ers per s ec o nd ( c ps). It has i n- b uil t RA M c hi ps t o st or e doc u me nt s o ut p ut f r o mt he c o mp ut er. A l ot of RA Mi s us e d whil e wor ki ng i n des kt op p ubli s hi ng a nd pri nti ng c o m - pli c at e d doc u me nt s w i t h c ol o ur a nd ma ny gr a p hi cs. It al s o has RO M c hi ps t o st or e f o nt s a nd i t s o wn s mall de di c at e d pr ocess or.

Ink-Jet Printer

I nk- J et pri nt er i s ver y pop ul ar as i t i s i ne x pe nsi ve a nd al s o off ers t he f acili t y of c ol o ur pri nti ng. It has nozzl es havi ng ver y fi ne hol es, whi c h pri nt s t he c har act ers by s pr ayi ng patt er ns of i nk o n t he pa per. The i nk c o mes o ut of t he nozzl e i n f or m of va po urs. It f or ms t he desi r e d l ett er or s ha pe at t he desi r e d pl ace aft er passi ng t hr o ug h a r efl ecti ng pl at e. I nk-j et pri nt er i s sl o wer i n s pee d whi c h pri nt s ar o und 4 pages of t e xt per m i n ut e ( pp m). It pri nt s i n a s o me what l o wer r es ol uti o n ( 300- 720 dpi ) t ha nl as er pri nt ers. So me ne w , e x pe nsi ve i nk-j et pri nt ers pri nt up 1200 or 1400 dpi. A vari ati o n o n i nk-j et t ec hnol ogy i s t he b ubbl e-j et pri nt er It us es m i ni at ur e he ati ng el e me nt s t o f or ce s peci all y f or mul at e d i nks t hr o ug h pri nt he a ds w i t h 128 ti ny nozzl es. Thi s t ec hnol ogy i s c o mmo nl y us e d i n port a bl e pri nt ers

Plotters

It i s a s peci al o ut p ut de vi ce t hat i s desi g ne d t o pr o d uce s har p q uali t y a nd l ar ge si z e d gr a p hi cs, dr a w i ngs, ma ps i n di ff er e nt c ol o ur s c he mes. The y ar e ge ner all y us e d f or desi g ni ng a ppli c ati o ns wher e hi g h q uali t y gr a p hi c o ut p ut o n l ar ge s heet of pa per i s r e q ui r e d. Thes e de vi ces have bec o me l ess pop ul ar over t he ye ars, b ut still pr o d uce hi g h- q uali t y dr a w i ngs Ther e ar e 2 t y pes of pl ott ers:

( a ) Dr u m pl ott ers

(b ) Fl at be d pl ott ers

Sound Systems/Speakers

Thes e ar e t he o ut p ut de vi ces whi c h o ut p ut s o und or a udi oi n t he f or mof s peec h a nd musi c Thes e o ut p ut de vi ces have i mport a nt i mpli c ati o ns f or t hei r us e by vi s uall y i mpai r e d pe opl e bec a us e t o oper at e c o mp ut ers t he y r el y he avil y o n s o und s yst e ms.

Peri p her al de vi ces: All de vi ces c o nnect e d t o t he port s of c o mp ut er ar e c all e d Peri p her al de vi ces. The y c a n be i np ut de vi ces, o ut p ut de vi ces a nd st or age de vi ces

Storage Devices

Thes e de vi ces ar e us e d t o st or e dat a or pr ogr a ms. Thes e de vi ces ar e no n- v ol a - til e. Thes e c a n be ei t her i nt er nall y b uil t i nt o t he c o mp ut er or c a n be e xt er nall y att ac he d t o t he c o mp ut er vi a US B port. A Har d di s k dri ve i s c o mmo nl y us e d st or age de vi ce a nd c a n be ei t her e xt er nal or i nt er nal. Ot hers i ncl ude pe n dri ve, fl oppy di s k, me mor y c ar d r e a der et c.

Vol atil e me mor yi s t he o ne i n whi c h t he c o nt e nt s ( dat a or pr ogr a ms) st or e d o n t he st or age me di u m get s er as e d off o nce t he po wer s uppl y t o t he c o mp ut er i s s w i t c he d off No n- v ol atil e me mor y i s j ust t he opposi t e

1.5 FUNCTIONAL UNITS OF A COMPUTER

A c o mp ut er s yst e m has f o ur basi c f uncti o nal uni t s whi c h ar e li st e d as under :

( 1) I np ut Uni t

( 2) Out p ut Uni t

( 3) Me mor y Uni t

( 4) Co nt r ol Uni t

( 5) Ari t h meti c Logi c Uni t

The l ast t wo uni t s i e Co nt r ol Uni t, Me mor y Uni t a nd Ari t h meti c a nd Logi c uni t t oget her w i t h i nt er nal pr ocess or c o nsti t ut e Central Processing Unit (CPU) , t he br ai n of a c o mp ut er. J ust Li ke a h u ma n br ai n, i t c o nt r ol s t he fl o w of i nf or mati o n a nd t ell s ot her c o mpo ne nt s what t o do. The s pee d of t he c o mp ut er de pe nds upo n what t y pe of CP Ui s us e d. A CP U ge ner at es l ot s of he at; a nd t her ef or e, t her e i s us uall y a s mall f a n ne ar by t o c ool i t do wn. The f uncti o nal r el ati o n a mo ng t he vari o us c o mpo ne nt s of a c o mp ut er c a n be s ho wn s c he mati c all y as f oll o ws:

CENTRAL PROCESSING UNIT (CPU)

I np ut uni t

Co nt r ol uni t

Out p ut uni t

Me mor y uni t

Ari t h meti c & Logi c uni t ( Pri mar y Me mor y : RA M , RO M )

Sec ondar y Me mor y: Har d di s k, C D ’ s, DVD ’ s, Pe ndri ves, et c.

FIGURE 1.5 : SCHEMATICALLY DIAGRAM OF CPU

The Process

W i t h t he us e of i np ut de vi ces dat a or i nst r ucti o ns ar e e nt er e d i nt o a c o mp ut er. The i np ut de vi ces li ke ke y boar d, mo us e, et c. ar e c o mmo nl y us e d t o i np ut dat a a nd i nst r ucti o ns. W i t h t he hel p of a ke y boar d al p ha n u meri c c har act ers a nd s y mbol s ar e fi rst c o nvert e d i nt o mac hi ne l a ng uage a nd t he n s e nt t o CP U . The mo us e i s us e d t o pi c k or s el ect a c o mma nd f r o mt he mo ni t or s cr ee n.

The ce nt r al pr ocessi ng uni t c o mpri s es a pr ocess or whi c hi nt er pr et s t he pr ogr a m i nst r ucti o ns a nd ma nages t he fl o w of dat a. The dat a i s fi rst s e nt t o c o nt r ol uni t whi c h de pe ndi ng upo n t he nee d s e nds i t t o ari t h meti c a nd l ogi c uni t or t o me mor y uni t I f nee d be t he ari t h meti c a nd l ogi c al uni t pr ocess es t he dat a a nd c o nvert s i t i nt o i nf or mati o n. The pr ogr a mi nst r ucti o ns ar e pr ocess e d o ne at a ti me al o ng w i t h t he necess ar y dat a The r es ul t s o bt ai ne d f r o mt he pr ocess ar e t he n s e nt t o me mor y uni t a nd t he ne xt i nst r ucti o n i s pr ocess e d. Thi s pr ocess i s r e pe at e d until t he e nti r e pr ogr a mi s e xec ut e d.

The r es ul t s s o o bt ai ne d ar e t he n s e nt t o o ut p ut uni t s s o t hat t he us ers ( h u ma n bei ng) c a n underst a nd a nd us e t he i nf or mati o n s o ge ner at e d

All t he uni t s be i t i np ut uni t, c o nt r ol uni t, ari t h meti c a nd l ogi c uni t, me mor y uni t or o ut p ut uni t, wor k i n c oor di nati o n s o t hat t he dat a pr ocessi ng r e mai n s moot h a nd c o mp uti ng r e mai ns us er f ri e ndl y.

The i ndi vi d ual r ol e of t hes e uni t s i s e x pl ai ne d bel o w:

Input Unit

The i np ut uni t us es t he a ppr opri at e met ho d t o e nt er dat a or pr ogr a mi nst r uc - ti o ns t o t he c o mp ut er s yst e m . It c o nvert s t he dat a i nt o a s ui t a bl e f or m t hat c a n be underst oo d by t he c o mp ut er.

Di ff er e nt t y pes of dat a nee d di ff er e nt i np ut met ho ds ( de vi ces). For e xa mpl e f or e nt eri ng bar c o de dat a a bar c o de r e a der i s r e q ui r e d.

Arithmetic and Logic Unit

The ari t h meti c-l ogi c uni t ( AL U) perf or ms ari t h meti c a nd l ogi c al oper ati o ns o n t he dat a Thi s s ecti o n of t he mac hi ne c a n be r el ati vel y s mall c o nsi sti ng of ci rc ui t s a nd r e gi st ers whi c h perf or mari t h meti c ( + ,, × , /) a ndl ogi c al ( > , < , <= , >= , et c. ) oper ati o ns. The Ari t h meti c-l ogi c uni t whi c h c a n perf or m mat he mati c al or l ogi c al oper ati o ns f or ms t he bac k bo ne of t he c o mp ut ers. Aft er c o mpl eti ng t he r e q ui r e d pr ocess i t r et ur ns t he o ut p ut t o c o nt r ol uni t.

Control Unit

The c o nt r ol uni t c o nt r ol s a nd c oor di nat es t he over all f uncti o ni ng of t he c o mp ut er s yst e m . It i s t he ma nager of t he c o mpo ne nt s of t he c o mp ut er. It s e nds c o mma nd si g nal s a nd c o nt r ol s t he s e q ue nce of i nst r ucti o ns t o be e xec ut e d. It i s r es po nsi bl e not o nl y f or ma nagi ng t he s e q ue nce of t he i nst r ucti o ns t o be perf or me d b ut al s o t he r et ri e val of i nst r ucti o ns i n t he pr oper s e q ue nce.

The f uncti o n of t he c o nt r ol ci r c ui t r y i n a ge ner al p ur pos e c o mp ut er i s t o i nt erpr et t he i nst r ucti o ns a nd t he n s e q ue nce t he necess ar y si g nal s t o t hos e s ecti o ns of t he c o mp ut er whi c h will perf or mt he i nst r ucti o ns.

Memory Unit:

The me mor y uni t st or es all t he i np ut dat a a nd t he r es ul t s. Me mor y Uni t of a c o mp ut er c a n be di vi de d i nt o t wo: pri mar y me mor y a nd s ec o ndar y me mor y. The pri mar y me mor y of a c o mp ut er or mai n me mor y i s c all e d

Random Access Memory (RAM), a nd Read

Only Memory (ROM).

RA Mi s a s e m i - c o nd uct or c hi p. It i s a v ol atil e me mor y, as l o ng as po wer i s o n t he i nf or mati o n st or e d i n i t r e mai ns Once t he po wer i s l ost, t he i nf or mati o n st or e d i n t he RA M al s o get s er as e d. RO M c o nt ai ns i nst r ucti o ns f or t he m i cr oc o mp ut ers. It f urt her may be di vi de d i nt o t wo: Programmable Read Only Memory (PROM) , o ne ti me pr ogr a mma bl e no n- v ol atil e me mor y c hi ps t hat ar e ma n uf act ur e d bl a nk a nd de pe ndi ng upo n t he t ec hnol ogy c a n be pr ogr a mme d at waf er, fi nal t est or i n s yst e m , a nd Erasable Programmable Read Only Memory (EPROM) , a t y pe of me mor y c hi p t hat r et ai ns i t s dat a whe n t he po wer s uppl y i s s w i t c he d off. The pr ogr a mmes st or e d o n EP RO M c a n be er as e d by e x posi ng i t t o ver y st r o ng ul t r avi ol et li g ht s o ur ce.

The c o nt e nt s of RO Mar e det er m i ne d at t he ti me of ma n uf act uri ng of t he c hi ps. RO Mi s not a v ol atil e me mor y. The i nf or mati o n st or e d does n ’ t get er as e d e ve n i f t he po wer i s l ost. The most i mport a nt RO M c hi p i s t he Basic Input/Output

System or BIOS . The BI OS i s a c oll ecti o n of s mall c o mp ut er pr ogr a ms b uil t i nt o a RO M c hi p.

The s ec o ndar y me mor y i s i n t he f or m of a har d di s k whi c h i s a no n- v ol atil e me mor y ge ner all y me as ur e d i n Gi ga byt es ( GB), t he ot her s ec o ndar y me mor y de vi ces ar e pe n dri ves, C D ’ s, DVD ’ s, et c. Thes e ar e us e d t o st or e dat a per mane ntl y. Thes e ar e al s o c all e d bac k up me mor y a nd ar e us e d t o kee p t he dat a f or a ver y l o ng peri o d of ti me.

Output unit: The o ut p ut uni t c o nvert s t he i nf or mati o n ge ner at e d by c o mp ut ers i n mac hi ne l a ng uage t o t he f or mi n whi c h t he us er c a n underst a nd. A vari et y of o ut p ut de vi ces ar e us e d f or di ff er e nt p ur pos es li ke mo ni t ors t o di s pl ay t he i nf or mati o n, pri nt ers t o pri nt t he o ut p ut, s pe a kers t o pr ovi de a udi o o ut p ut, et c.

Role of Registers and Cache

Register , a s peci al p ur pos e me mor y i s i nst r u me nt al i n movi ng dat a t o a nd f r o m t he mai n me mor y whil e t he dat a pr ocessi ng i s e xec ut e d. To e xec ut e a n i nst r ucti o n t he CP U us es t hes e r e gi st ers f or hol di ng dat a f or pr ocessi ng. Re gi st ers, t ho ug h a part of CP U , do not f or m part of mai n me mor y. Onl y a pi ece of dat a c a n be hel d by t he r e gi st ers at a ti me. Whil e t he i nst r ucti o ns ar e under e xec uti o n t he r el e va nt dat a ar e r ecei ve d by t he r e gi st ers, hel d by t he r e gi st ers t e mpor aril y a nd t he n t he dat a i s pass e d o n by t he r e gi st ers as per t he i nst r ucti o ns f r o mt he c o nt r ol uni t For e xec uti ng t he ne xt i nst r ucti o n t he

s a me pr ocess i s r e pe at e d. The r e gi st ers have ver y li m i t e d a nd s peci fi e d st or age c a paci t y I n M i cr o Co mp ut ers t hat we us e nor mall y 14 r e gi st ers ar e pr es e nt

i s a s mall a nd f ast er Me mor y t hat i s b uil t i nt o a c o mp ut er ’ s

CP U or l oc at e d ne xt t o i t The CP U us es c ac hes f or c opyi ng t he dat a f r o mt he most f r e q ue ntl y us e d l oc ati o ns of mai n Me mor y. It r e d uces t he aver age ti me t o access Me mor y Whe ne ver s o me dat a i s access e d f r o m a ny l oc ati o n, t he c ac he Me mor y st or es t he l oc ati o n a nd t he ne xt ti me y o u wa nt t o access t he s a me dat a t he CP U fi rst s e ar c hes i t i n t he c ac he Me mor y a nd t he n i t moves t o t he mai n Me mor y. I f t he dat a nee de d i s f o und i n c ac he me mor y i t i s k no wn as cache hit , i f not, i t i s c all e d

Cache Memory

Cache Miss .

The Cac he Me mor y i ncr e as es t he c o mp uti ng s pee d as t he CP U does n ’ t have t o us e t he Mot her boar d s yst e m b us f or t he dat a t r a nsf er. Whe n t he dat a i s pass e d t hr o ug h s yst e m b us t hat ma kes t he s yst e m sl o w t o i t s Mot her boar d c a pa bili ti es.

I f t he Cac he i s b uil t i nt o t he CP U i t s el f i t i s r ef err e d as l e vel 1 ( L 1) c ac he a nd i f i t i s l oc at e d o n a s e par at e c hi p ne xt t o t he CP U i t i s k no wn as l e vel 2 ( L 2). I n s o me CP U ’ s bot h L 1 a nd L2 c ac he i s b uil t i n o n a s e par at e c ac he c hi p t hat i s desi g nat e d as Le vel 3 ( L 3) c ac he.

For example : Whe n y o u access a we b page f or t he fi rst ti me y o ur c o mp ut er st or es a c opy of t he li nk of t he ht m l page The ne xt ti me y o u e nt er t he s a me URL y o ur c o mp ut er fi rst l ooks i n t he c ac he Me mor y a nd i f t he r e q uest e d page i s avail a bl e t her e i t r et ur ns ot her w i s e i t moves o n t o s e ar c h t he we b f or t he r e q uest e d we b page.

1.6 CHARACTERISTICS OF A COMPUTER

The c o mp ut ers have t he f oll o w i ng c har act eri sti cs:

(a) Speed: Co mp ut ers wor k at a n i ncr e di bl e s pee d The s pee d w i t h whi c h i t perf or ms t he i nst r ucti o ns a nd c al c ul ati o ns i s be y o nd h u ma n c a pa bil - i ti es. As c o mpar e d t o h u ma n bei ng i t c a n perf or m t he oper ati o ns i n a m i n ut e what a h u ma n bei ng c a nnot perf or m d uri ng hi s e nti r e li f e ti me. The c o mp ut er pr es e nt i n t he mo der n worl d has t he s pee d of na no a nd pi c o s ec o nd.

(b) Accuracy: Co mp ut ers ar e ver y acc ur at e. It may r et ur n err ors o nl y i f t her e i s s o me pr ogr a m i ng err ors or t he i np ut i s err o ne o us whi c h may al most al ways be att ri b ut e d t o h u ma n. It i s gi ve n a s peci al t er m GI GO ( Gar bage I n Gar bage- Out) whi c h me a ns we get f a ul t y r es ul t s d ue t o i nacc ur at e i nst r ucti o ns or f a ul t y dat a.

(c) Diligence: As c o mpar e d t o h u ma n bei ngs t he c o mp ut ers ar e hi g hl y c o n - si st e nt. The y do not s uff er f r o mt he h u ma n t r ai t s of bor e do m , ti r e dness a ndl ac k of c once nt r ati on . Co mp ut ers perf or mvol u m i no us a nd r e peti ti ve j o bs w i t ho ut t a ki ng a ny r ef r es h me nt.

(d) Versatility: All mo der n c o mp ut ers c a n perf or m di ff er e nt ki nds of t as ks si mul t a ne o usl y. Co mp ut ers ar e vers atil e mac hi nes. The y ar e c a pa bl e of perf or m i ng ma ny t as k be i t r ail way/ai r r es er vati o n, ba nki ng oper ati o ns, we at her f or ec asti ng a nd ma ny mor e It c a n s w i t c h f r o m o ne t as k t o a not her i nst a ntl y whil e perf or m i ng t he pr e vi o us o ne i n bac kgr o und.

(e) Automatic: The c o mp ut ers ar e a ut o mati c. Once a t as k i s assi g ne d t o i t, i t may e xec ut e t he pr ocess w i t ho ut a ny i nt er ve nti o n of t he us er.

(f) Memory: Unli ke h u ma n bei ngs c o mp ut ers do not s uff er f r o mt he pr o b - l e ms of f or getti ng t he ol d i nf or mati o n. Vol u mes of i nf or mati o n c a n be st or e d i n c o mp ut ers The i nf or mati o n st or e d o n c o mp ut ers c a n ne ver be f or g ott e n a nd c a n be e asil y r et ri e ve d i n no ti me.

1.7 ADVANTAGES OF THE COMPUTERS

Ther e ar e ma ny a dva nt ages of usi ng t he c o mp ut ers i n o ur li f e. So me of t he m ar e li st e d bel o w :

(i ) W i t h t he hel p of c o mp ut er a ppli c ati o ns a nd pr ogr a ms ma ny ti me c o ns u m i ng acti vi ti es li ke s pelli ng c hec k, di cti o nar y, ha ndli ng vast n u meri c al dat a, et c. c a n be do ne i n no ti me.

(ii ) W i t h t he hel p of i nt er net pe opl e c a n i nt er act a nd c o mmuni c at e i n r e al ti me acr oss t he worl d.

(iii ) W i t h t he hel p of i nt er net t he i nf or mati o n e xc ha nge has bec o me ver y e as y a nd at al most no c ost. Ho we ver, i n s o me c as es t he us er nee d t o pay f or t he i nf or mati o n.

(iv ) A n u mber of c opi es of a ny doc u me nt s c a n be cr e at e d i n s ec o nds whi c h c o ul d t a ke a n u mber of ho urs of t he h u ma n bei ng t o do s o.

( v ) Pe opl e c a n do t hei r offi ce wor k f r o m a ny wher e, as i n c as e of vi rt ual offi ce, a nd c a n s par e mor e ti me w i t h t hei r f a mili es. It s aves t hei r ti me t o c o mmut e t o t he offi ce a nd r e d uces c ost of s etti ng up offi ce.

(vi ) Co mp ut ers assi st t he pe opl e w i t h di s a bili t y t o perf or mt hei r s o me of t he acti vi ti es e. g. t o vi s uall y c hall e nge d pe opl e i n t he st udi es usi ng s cr ee n r e a di ng s oft war e et c. It i s r e all y a boo n f or vi s uall y c hall e nge d pe opl e.

(vii ) By usi ng c o mp ut ers n u mer o us dat a c a n be st or e d i n s mall si z e st or age de vi ce f or a ver y l o ng ti me peri o d w i t ho ut t he f e ar of f or getti ng i t. (viii ) W i t h t he us e of c o mp ut er s oft war e pl agi ari s m c a n be c hec ke d a nd c o nt r oll e d.

It i s ne xt t o i mpossi bl e t o li st do wn all t he a dva nt ages of c o mp ut ers a nd t her ef or e t he di s c ussi o n i s li m i t e d t o t hes e ar e as o nl y. Ther e ar e vari o us ot her a dva nt ages of t he c o mp ut ers al s o

1.8 USES OF COMPUTERS

(i) Education. The c o mp ut ers ar e us e di n e d uc ati o n s yst e mi n vari o us ways. The r es ul t s of ma ny e xa ms ar e upl oa de d by t he c o ncer ne d boar d or uni versi t y a nd t he e xa m i nees get t hei r r es ul t s do wnl oa de d i n no ti me.

W i t h t he hel p of c o mp ut ers o nli ne e xa m i nati o n has bec o me possi bl e whi c h has r e d uce d t he s pace r e q ui r e me nt by t he i nsti t uti o ns f or hol di ng t he e xa m a nd al s o r et ur n i nst a nt r es ul t s.

Co mp ut ers al s o hel pi n s pr ea di ng e ducati ont hr o ug h e-l ear ni ng pr ogr a ms. For e xa mpl e, PA N Af ri c a e-l e ar ni ng pr oj ect of Gover n me nt of I ndi a t o s pr e a d hi g her e d uc ati o n i n Af ri c a n c o unt ri es w i t h t he hel p of vi rt ual cl ass r oo ms.

The t e ac hi ng ai ds li ke ppt pr es e nt ati o n et c. have i ncr e as e d t he i nt er est of t he st ude nt s i n a cl ass r oo mr es ul ti ng i n bett er t e ac hi ng. W i t h t he hel p of c o mp ut er t ec hnol ogy e-l e ar ni ng i s avail a bl e 24 × 7.

(ii) Health. W i t h t he hel p of c o mp ut ers ne wli f e s avi ng e q ui p me nt have bee n de vel ope d a nd ma ny li f es avi ng dr ugs have bee n ma de. The c o mp ut ers pr ovi de assi st a nce i n me di c al t r e at me nt at all st ages, be i t di ag nosi ng a di s e as e, c hec k up of bo dy, vari o us t est s or oper ati o ns, et c. The doct ors c a n no w pr ovi de c o ns ul t a nc y t o t hei r pati e nt s o nli ne. Al s o, I T has e na bl e d k no w l e dge s hari ng a mo ng doct ors t hr o ug h s peci al k no w l e dge bas e d s oft war e.

(iii) Business.

The c o mp ut ers ar e us e di n al most all s ort s of b usi ness f or vario us p ur pos es li ke billi ng, budgeti ng, acc o unti ng, r e porti ng, pr es e nt ati ons, et c The us e of c o mp ut ers has ma de t he b usi ness pr ocessi ng f ast er a nd has r e d uce d h u ma n eff ort s. Onli ne s hoppi ng has ope ne d ne w st or es at e ver y o ne ’ s des kt op as no w vari o us pr o d uct s c a n be p ur c has e d o nli ne f r o m si tti ng at ho me. Thi s has hel pe d t he b usi ness i n i ncr e asi ng t hei r r e ve n ue a nd r e ac hi ng di st a nt part s of t he worl d. The f oll o w i ng ar e wort h c o nsi deri ng u

Dat a st or age, ma ni p ul ati o n a nd di st ri b uti o n: I Ti s us e di n b usi ness t o st or e t he dat a, pr ocess i t a nd di st ri b uti ng i t effi ci e ntl y. It hel ps i n pr e pari ng r e port s f or t he vari o us l e vel s of ma nage me nt by usi ng vari o us t y pes of Information Systems . u

Tec hnol ogi c al a ppli c ati o ns: Vari o us t ec hnol ogi c al a ppli c ati o ns ar e us e d i n b usi ness li ke dat a bas e ma nage me nt s yst e ms, wor d pr ocess or, s pr e a ds heet s, acc o unti ng s oft war e a nd ma ny ot her s oft war e whi c h has i ncr e as e d t he effi ci e nc y of oper ati o ns.

u

JI T : I T has hel pe d i n i nt e gr ati ng t he b usi ness pr ocess es w i t h t he s uppli ers al s o t o ma nage i t s i nve nt or y l e vel s t hr o ug h J ust-i n- Ti me ( JI T) s yst e m whi c h has r es ul t e d i n l o weri ng i nve nt or y c ost s

u

u

Cost r e d ucti o n: I T has al s o hel pe d t o p ut a li m i t o n ma npo wer e x pa nsi o n, a nd al s o t he pa per wor k, t her e by r e d uci ng c ost s

E- Co mmer ce: I T has e na bl e d b usi ness es t o ve nt ur e i nt o e- c o mmer ce E- c o mmer ce i s b uyi ng a nd s elli ng s er vi ces a nd g oo ds over t he I nt er net whi c h has ma de t hei r g oo ds avail a bl e 24 × 7 w i t h r e d uce d c ost s

u

Co mmuni c ati o n: I T has al s o e na bl e d c o mmuni c ati o n bet wee n b usi ness es worl d w i de vi a e- mail s a nd we b c a mer as, mo bil e p ho nes, et c.

u

u

Port a bili t y: I T has r es ul t e d i n de vel op me nt of mo bil e de vi ces li ke l a pt ops a nd mo bil e p ho nes whi c h has e na bl e d b usi ness t o be c o nd uct e d f r o ma ny wher e E mpl oyees c a n no w e nj oy t he be nefi t of wor k- f r o m - ho me.

Ent er pri s e Res o ur ce Pl a nni ng ( E RP): E RP i s b usi ness pr ocess ma nage me nt s oft war e t hat i nt egr at es all f uncti ons of or ga ni z ati on s uc h as fi na nce, pr o d ucti o n, s al es, fi na nce et c w i t h t he hel p of s ui t e of i nt e gr at e d a ppli c ati o ns. Thi s e ns ur es t hat t he dat a i s ke pt up dat e d a nd i s r e a dil y avail a bl e as all de part me nt s ar e i nt e gr at e d t o t he E RP . Vari o us E RP pac kages ar e avail a bl e whi c h c a n ei t her be pr opri et ar y s oft war e or F OSS( Fr ee a nd Ope n So ur ce Soft war e) e. g. of F OSS E RP : E RP NE XT ( f or s mall a nd me di u m si z e e nt er - pri s es, Fe de na ( f or s c hool s a nd uni versi ti es); e. g. of pr opri et ar y s oft war e: my S AP f r o m S AP , Pe opl e Soft f r o m Or acl e.

(iv) Travel. No w- a- days pl a nni ng holi days has bec o me ver y e as y as t he avail a bili t y of ti c ket s i n t r ai ns or pl a nes c a n be c hec ke d usi ng i nt er net f r o msi tti ng at ho me a nd t he s a me c a n be booke d as per t he us ers c o nve ni e nce a nd t he i nt er est. I n t he s a me ma nner t he hot el s c a n al s o be booke d o nli ne.

(v) Research.

The c o mp ut ers ar e e xt e nsi vel y us e d i n r es e ar c h, be i t def e nce r es ear c h, s oci al r es ear c h, met e or ol ogi cal r es ear c h, me di cal r es ear c h, et c. Al most e ver y we a po n us es a s oft war e, e.g., M i ssil es. The c o mp ut ers ar e us e d t o desi g n a nd de vel op vari o us we a po ns, t o k no w t he c ha nges i n e art h’ s at mos p her e a nd f or we at her f or ec asti ng. I n s oci al s ci e nce r es e ar c hes al s o c o mp ut ers ar e us e d t o pr ocess t he dat a t o get t he r es ul t s.

(

vi) Banking.

The c o mp ut ers have ma de ba nki ng possi bl e 24 × 7, i.e. 24 ho urs a nd s e ve n days a wee k. The ba nk acc o unt c a n be oper at e d, t he pay me nt s ca n be ma de, t he a mo unt s ca n be t r a nsf err e d f r o mone acc o unt t o a not her at a ny ti me whet her t he ba nk i s ope ne d or cl os e d. W i t h t he hel p of t he c o mp ut ers ba nks pl ace d AT Ms ( Aut o mat e d Tell er Mac hi ne)

whi c h hel ps i n w i t hdr a w i ng c as h by usi ng AT Mc ar d e ve n w i t ho ut g oi ng t o t he ba nk Thi s has r e d uce d t he l o ng wai ti ng li nes i n t he ba nks

(vii) Communication. I n ol de n days i f s o me mess age ha d t o be s e nt i t us e d t o t a ke at l e ast fi ft ee n t o t we nt y days i n getti ng bac k t he r es po ns e of t he mess age as t he post al mail was us e d. But w i t h t he hel p of c o mp ut ers, c o mmuni c ati o n has bec o me i nst a nt a ne o us The e- mail s have bec o me a f ast er way of c o mmuni c ati o n. The mo bil e p ho nes have ma de i t possi bl e t o li st e n t he pers o n o n t he ot her si de i rr es pecti ve of t he di st a nce, a nd mess ages ar e no w deli ver e d i n s ec o nds.

The ar e as di s c uss e d a bove b ut ar e not e x ha usti ve as t her e ar e ma ny ot her ar e as al s o i n whi c h c o mp ut ers ar e us e d have not bee n di s c uss e d her e.

1.9 LIMITATIONS OF COMPUTERS

The c o mp ut ers ar e f ast, acc ur at e, a nd dili ge nt. It c a n perf or m most of t he acti vi ti es of h u ma n bei ng i n a bett er ma nner; e ve n t he n, i t poss ess es t he f ol - l o w i ng li m i t ati o ns:

(i) Zero IQ: The c o mp ut ers do not have I Q (i nt elli ge nce q uoti e nt) Eac h a nd e ver y st e p nee ds t o be t ol d t o t he m . The y ar e bar e i di ot mac hi nes whi c h c a nnot ha ndl e e ve n a si ngl e e xt r a f ull st op or c o mma.

(ii) No Decision Making power:

The c o mp ut ers l ac k deci si o n ma ki ng po wer as t he y do not poss ess a ny acti ve br ai n The y c a n o nl y act as per i nst r uc - ti o ns pr ovi de d t o t he m .

(iii) No creativity: The c o mp ut ers ar e not cr e ati ve as t he y c a n perf or m o nl y what i s i nst r uct e d. The y c a nnot cr e at e a nyt hi ng o n t hei r o wn.

(iv) Dependence on program:

The c o mp ut ers f ull y de pe nd o n t he pr ogr a m wri tt e n f or t hei r perf or ma nce. I f t he pr ogr a mi s not c orr ectl y wri tt e n or i t i s err o ne o us t he r es ul t s o bt ai ne d f r o m c o mp ut ers will al s o be err one o us. The c o mp ut er c a nnot t a ke a ny c orr ecti ve me as ur es o n i t s o wn.

1.10 CONCEPTS OF COMPUTING, DATA AND INFORMATION

Computing: Co mp uti ng i s a n acti vi t y t hat us es bot h c o mp ut er har d war e a nd s oft war e t o ac hi e ve s o me pr e- de fine d g oal s Thos e dat a pr ocessi ng g oal s may be as si mpl e as a si mpl e mat he mati c al c al c ul ati o n or as t e di o us as we at her f or ecasti ng. The dat a pr ocessi ng r e q ui r e me nt s var y w i t h di ff er e nt pe opl e havi ng di ff er e nt i nf or mati o nal nee ds. For i nst a nce, t he poli ti ci a ns nee d i nf or mati o n a bo ut t he nu mber of vot ers i n a c onsti t ue ncy, t hei r c o mposi ti on , a ndt he pr essi ng i ss ues; t he ma nagers nee d i nf or mati o n a bo ut t hei r b usi ness e nvi r o n me nt; t he we at her f or ec asti ng r e q ui r es dat a a bo ut t he we at her patt er n, et c. Pr ocessi ng s uc h v ol u m i no us dat a ma n uall y i s err or pr o ne, c ostl y a nd ti me c o ns u m i ng. Us e of c o mp ut er har d war e a nd s oft war e e ns ur es ti mel y avail a bili t y of acc ur at e, r el e va nt a nd up- t o- dat e dat a a nd i nf or mati o n.

Computer Applications in Business

AUTHOR : HEM CHAND JAIN, H.N.

TIWARI

Description

This is a comprehensive & authentic textbook written to impart computer skills and knowledge to commerce students & enhance their understanding of information technology tools in handling business operations. The book’s focus is on the application part while providing basic information about computers for first-time readers.

This book aims to fulfil the requirement of students of the following:

u B.Com. (Hons.) | Semester – IV | Paper BCH 4.3 under CBCS Program

u Non-Collegiate Women’s Education Board (NCWEB)

u School of Open Learning (SOL) of the University of Delhi

u Central Universities throughout India

The Present Publication is the 7 th Edition, authored by Dr. Hem Chand Jain & Dr. H.N. Tiwari, with the following noteworthy features:

u [ Simple, Systematic & Comprehensive Explanation ] The subject matter is presented in a simple, systematic method along with a comprehensive explanation of the concept and theories underlying Computer Applications in Business. The focus of this book is on the application part.

u [ Diagrams and Illustrations for easy Understanding ] Usage of diagrams & illustrations to enhance the comprehension of various concepts and systems of computers

u [ Business Examples ] Comprehensive coverage of business examples to illustrate the concepts

u [ MS Excel in Business ] Separate chapter to demonstrate how excel is helpful in decision making

u [ Summary and Review Questions ] are given at the end of each chapter to evaluate and understand the concept

u [ Previous Exam Questions & Answers ] are presented in this book, which includes the following:

n B.Com. (Hons.) | SEM. IV – 2017

n B.Com. (Hons.) | SEM. IV – 2018

n B.Com. (Hons.) | SEM. IV – 2019

u [ Student-Oriented Book ] This book has been developed keeping in mind the following factors:

n Interaction of the author/teacher with their students in the classroom

n Shaped by the author/teacher’s experience of teaching the subject matter at different levels

n Reactions and responses of students have also been incorporated at different places in the book