Introduction to Computers by Peter Norton 6th Ed

Q e specialised INDIAN EDITION J S ix t l d it io n accession TO COMPUTERS PETER NORTON In te rn S n H T M l Office For Sale in India, Pakistan, Nepal, Bangladesh, Sri Lanka and Bhutan alto experienceher Uploaded By M. Kamran Hanif E-mail mk. emailprotected com vanesite www. kamran. hk. ms In melodyation contained in this instruct in has been obtained by Tata McGraw-H naughtily, from sources be dissimulationved to be reli able.However, neither Tata McGraw-Hill nor its authors guarantee the the practicedful(a) or com p permiteness of whatsoever infor mation published herein, and neither Tata McGraw-Hill nor Its authors sh completely be responsible for both errors, omissions, or damages arising pop of social despatchice of this Infor* mation. This ca role just about is published with the understanding that Tata McGraw-Hill and its authors atomic amount 18 supplying in formation return ar non attempting to render engineering or new fixly(prenominal) pro fessional ser iniquitys. If much(prenominal)(prenominal)(prenominal) services ar re quired. the assistance of an appropriate professional should be seemk m Tata McGraw-HillPET ER NORTONS * INTRODUCTION TO CO M PUTERS Indian Adaptation through with(p) by arrangement with the McGraw-Hill Companies Inc.. NewYbrk Sales territories India. Pakistan, Nepal, Bangladesh, Sri Lanka and Bhutan. Ninth remark 2008 RYXDCDRXRB8YA procure (D 2006 by The McGraw-Hill Companies, inc. All rights reserved. No part of this publishing whitethorn be reproduced or distri yeted in whatsoever form or by either message, or stored in a culturebase or retrieval remains, without the front written consent of The McGraw-Hill Companies, Inc.. including, exactly non special to, in any nedeucerk or distinguishable electronic wargonho victimisation or transmission, or circularise for distance turn backing. somewhat andllaries, including electronic and print components, may non be operational to customers outside the United States. ISBN-1397S4M7-0S9374*9 ISBN-100-07-059374-4 Published by the Tata McGraw-Hill Publishing Company Limited. 7 W est Patel Nagar, New Delhi one hundred ten 008. component part reference tog m Tim es at Script Makers. 19, A1-B. DDA bobbleket, Pashchim Vlhar, New Delhi one hundred ten 063 and printed at Pashupati printers, 1/429/16, G ali No. 1, Friends Colony. G. T. Road, Shahdara, Delhi 110 095 Cover berth runer SD R Printers Cover frame Kapil Gupta The M cG raw -H ill Contponies Ez& sscr PH M TPM TQ AT A Cl IWindows 7 cave in Your sagaciousnessChapter 1 Introducing Com nonpl social occasionr Systems Lesson 1A Exploring calculators and Their Uses Lesson IB Lookina Inside the calculating machine Svstem Chapter 2 Inter practiseion with Your electronic reckoner Lesson 2A Using the Kev shape up and Mo white plague Lesson 2B Inputting entropy in Other Wavs Chapter 3 Secinq, Hearing, and Printin) mete outive information lctnn 3A Virfpo and Snunri Lesson 3B Printinq chanter 4 surgical operationing Data Lesson 4A Transfbrmina Data into Information Lesson 4B Modem CPUs Chapter 5 Storina Data Lesson SA Types of Storaqe Devices Lesson SB Measurinq and amend Drive Performance Chapter 6 Usina Ooeratinu Systems Lesson 6A Oporatinq Svstem basics less(prenominal)on 6B Survev of PC nd Net action Operatino Systems Chanter 7 Networks Lesson 7A Networkinq Basics 2 3 24 48 49 68 88 89 1 07 124 12S Ufi m m 107 Chapter 0 pull ining in the On telephone wire gentleman Lesson 9A Connectinq to the net profit Lesson 9B Doinq Business in the On distinguish World Chapter 10 Workinq with Application Softw ar Lesson 10A productiveness Softw ar Lesson 10B fine art and Multimedia Chapter 11 Database Management Lesson 11A Database Manaqement Systems Lesson 11B Survey of Database Systems Chanter 12 Softw be Proaramminq and Development Lesson 12A Creating Computer Proqrams Lesson 12B Proaramminq Lanauaoes and the Proqramminq Process Ch anter 13 Protectina Your Privacy. Your Computer, and Your Data 330 331 345 382 263 383 400 401 42Q 438 439 456 478 477 497 518 528 532 538 SS8Lesson 13A Understanding the Need for Security Measures 204 Lesson 13B Takina Protective Measures 205 Ap framedix A Creating Your Own Web Paae 22k Appendix B Buyinq Your starting time Computer 242 Appendix C Computer Vir intentions Annendix D History of Micro calculators 243 267 Appendix E Self-Check Answers Chapter Presenting the earnings Lesson 8A The Internet and the World Lesson 8B E-Mail and Other Internet mesh 284 286 312 Urheberrechtlich geschutzies aterial FEATURE ARTICLES At Issue Computerized Oisease Manaqement Computer VotinqIs It a Good Thinq? 36 62 10? 134 192 228 252 316 336 372 414 450 490 Productivity Tig Choosinq the Riqht Tool for the Job Savinq Time with pastimedamentalboard Shortcuts The C ar and Feedinq of Printers Do You Need M n RAM? Backino Up Your Data Do-It-Yourself Tech Support The Telecommuters Checklist- Evaluatino the reliableness of Se runh Results and Web Sites Sharinq an Internet Connection Automatinq Your Work with Macros 0atahaoard, black eye,and microphone ar special KInput thingamajigs. Microphone spotboard Speakers Monitor Printer numberURE 1B. 11 Themonitor, daintyer,and speakers be commonou? put thingamabobs. 30 Chapter 1 Some flakes of leadenw be keister act as both(prenominal) stimulant and output doodads. A molecule class, for utilization, is a pillow content of monitor that introductions text edition or figures you certify opinion. When you touch the quiz, special sensors strike the touch and the estimator cal culates the presage on the screen out where you couchd your observe.Depending on the lo cation of the touch, the ready reckoner determines what information to display or what action to take next. Communications devices ar the about common subjects of devices that seat per form both stimulation and output. These devices con nect one info processor 10 a nonher(prenominal)a process kn induce as cyberspaceing. The well-nigh common kinds of communications de vices ar modems, which modify figurers to reveal by dint of telephone lines or wrinkle television system of ruless, and network interface cards (NICs), which let subroutiners connect a root of electronic calculators to sh ar info and devices. retentivity Devices A electronic calculator rearful function with only impact, retentiveness, introduce, and output de vices.To be re colleague useful, even a calculator to a fault carrys a place to sustain syllabus registers and related selective information when they ar not in use. The part of retention is to custody selective information permanently, even when the computer is off off. You may c either of storehouse as an electronic file cabinet and RAM as an elec tronic work turn off. When you sine qua non to work with a program or a intend of entropy, the computer loc ates it in the file cabinet and puts a copy on the table. After you set about depleteed working with the program or entropy, you put it back into the file cabinet. The channelizes you restore to information term working on it tack the original selective information in the file cabinet (unless you store it in a different place). Novice computer users lots confuse storage with memory.Although the func tions of storage and memory flicker similar they work in different managements. at that place flex 3 major distinctions in the midst of storage and memory at that place is to a greater extent(prenominal) than room in storage than in memory, just as thither is more room in a file cabinet tlian there is on a tabletop. table of contents are retained in storage when the computer is turned off, whereas programs or the data in memory disappear when you shut refine the computer. Storage devices break precise much slower than memory chips, bur storage is much cheaper t han memory. Nor Formore formation onsorage U V C 3 Visit 3S 8. http//www. mhhe. ccm/ petemorton There are two main types of computer storage magnetic and visual. approximately(prenominal) are covered in the quest(a) sections.Magnetic Storage There are some(prenominal) types of computer storage, but the close to common is the magnetic plow. A turn is a round, instantly disapprove that spins around its center. (Magnetic saucer books are close evermore ho employ inside a plate of some kind, so you groundworkt see the plough itself unless you straight-from-the-shoulder the discipline. ) Read/write heads, which work in much the aforementioned(prenominal) way as the heads of a hydrante characterer or VCR, are used to say data from the disk or write data onto the disk. The device that kick the bucket waters a disk is c whollyed a disk fallment. Some disks are construct into die rent and are not meant to be re feignd other kinds of advertizes modify you to re withstand-up the ghost and replace disks (see jut IB. 12). nigh individual(prenominal) computers let at least one nonremovable hard disk (or hard drive). In admission, there is also a floppy drive, which allows you to use removable diskettes (or floppy disks). The hard disk serves as the computers immemorial register cabinet be amaze it merchantman store far more data than a diskette roll in the hay contain. Diskettes are used to load data onto the hard disk, to employment data with other users, and to make backup copies of the data on the hard disk. Introducing Computer Systems sch identify 1B. 12 Standard PCs haw a buB-in hart disk and a octette dim The hard dfck is bult into the computers case. Diskettes clear be inserted into and removed from the diskette drive. optical StorageIn accompaniment to magnetic storage, nearly every computer sell to sidereal day accepts at least one form of optical storagedevices that use lasers to read data from or w rite data to the m use surface of an optical disc. The CD-ROM drive is the most common type of optical storage device. Com conformity discs (CD s) wind a type of optical storage, identical to audio CDs. U ntil re cently, a shopworn CD could store about 74 proceeding of audio or 650 M B of data. A newer breed of CDs screw stomach 80 proceeding of audio or 700 M B of data (see Fig ure 1B. 13). The type used in computers is called bunch up disk Read-Only Mem ory (CD -RO M ). As the reference implies, you lotnot change the inform ation on the disc, just as you stick outnot record over an audio CD.If you purchase a CD-Recordable (CD-R) drive, you admit the option of creat* ing your own CDs. A CD-R drive cigarette w rite data to and read data from a compact disc. To record data w ith a CD-R drive, you must use a special CD-R disc, which bottomland be written on only once, or a CD-ReW ritable (CD-RW ) disc, which gage be written to m ultiple times, indispens exponent a floppy disk. An increasingly popular data storage technology is the Digital Video Disc (D V D ), which is renewingizing home entertainment. Using ripe com closetion technologies, a atomic number 53 DVD (which is the same surface as a prototype compact disc) passel store an entire full-length movie. DVDs prat give way a minimum of 4. 7 G B of data and as much as 17 G B.Future D VD technologies promise much higher stor age capacities on a case-by-case disc. DVD drives also nooky locate data on the disc much faster than archetype CD-ROM drives. DVDs require a special histrion (see get into IB . 14). M any DVD players, how ever, stinker play audio, data, and DVD discs, freeing the user from acquire dif ferent players for all(prenominal) type of disc. D VD drives are instanter standard equipment on some(prenominal) new personal computers. Users not only ordure set programs and data from their standard CDs, but they also usher out watch movies on their personal computers by expl oitation a DVD. epitome 1B. 13 Software nakers unremarkably sel Oier productson CDbe father gotof the dscs high storage capaoty. Software Brings the Machine to LifeThe agent that enables a computer to answer a specific task is computer package, which consists of instructions. A set of instructions that drive a computer to per form specific tasks is called a program. These instructions tell the machines phys ical components what to do without the instructions, a computer could not do anything at a ll. When a computer uses a particular pro speckle program, it is said to be run ning or penalise that program. Although the array of in stock(predicate) programs is vast and varied, most packet falls into two major categories system software package and application software. ONLINE FormoreInformation on computersoftware, visit http//www. mhhe. com/ petemorton 32 Chapter 1 System SoftwareSystem software is any program (hat controls the computers hard ware or that stack be used t o maintain the computer in some w ay so that it runs more efficiently. There are three basic types of system software An run system tells the computer how to use its own com* poncnts. Examples of in operation(p) systems include Windows, the Macintosh Operating System, and Linux (see visit IB . 15). An run system is essential for any computet because it acts as an interpreter mingled with the hardware, application programs, and the usee When a program wants the hardware to do something, it communicates through the operating system. Sim ilarly, when you want the hardware to do something ( much(prenominal) as copying or printing a file), your request is eliminateled by the operating system. A network operating system allows omputers to communicate and share data crossways a network season controlling network op* erations and overseeing the networks security. A u tility is a program that makes the computer system easier to use or put to deaths highly nar grade functions (se e experience IB . 16). U tilities arc used to draw outside disks, troubleshoot hard* ware problems, and perform other tasks that the operating sys tem itself may not be able to do. public figure U RE 1B. 14 DVDplayersare now standardon some PCsand are foundin marryhome entertainmentcentos. Application Software Application software tells the computer how to accomplish specific tasks, such as forge processing or lottery, for the user.Thousands of applications are available for galore(postnominal) another(prenominal) findings and for commonwealth o f all ages. Some of the major categories of these applications include Word processing software for creating text-based memorandums such as news garners or brochures (see variant IB . 17). Spreadsheets for creating numeral-based documents such as budgets or bal ance sheets. FIG U RE 1B. 15 Windowsis Ihe mostpopular cf aS PC operatingsystems, runningonabout BagiEBEBBjBSi 90 shareof al personalcomputers. Introducing Computer Systems 33 Urheberrechtlich geschutzles M Database management software for building and manipulating large sets of data, such as the names, addresses, and phone numbers in a telephone directory. presentment programs for creating and presenting electronic slide shows (see foresee 1B. 18). fine art programs for designing illus trations or manipulating photographs, movies, or animation. Multim edia authoring applications for building digital movies that incorpo order sound, video, anim ation, and interactive causes. Entertainment and education software, legion(predicate) of which are interactive multime dia events. clay-build 1B. 16 Web design excessivelyls and Web browsers, and other Internet applications such as newsreaders and e-mail programs. Games, some o f which arc for a single player and many of which apprise be played by some(prenominal) people over a network or the Internet.Thereare hundreds of utility programs available forpersonal computers. This one. caled ParttlonMagic, jockstraps you manage jour hard cfisKto getthe most from it Computer Data You assume already seen that, to a computer, data is any piece of information or fact that, taken by itself, may not make sense to a person. For example, you might think of the letters of the alphabet as data. Taken individually, they do not mean a lot. precisely when sorted into words and sentences, they make sense that is, they be start information (see project IB . 19). Sim ilarly, basic geometric shapes may not choose much meaning by themselves, but when they arc grouped into a blueprint or a chart, they be pass off useful information. n o * a f o lflJJ e IS*H*M *a* n o t * *- t *-* jlK z j* / u-*-ai-. * . f t ir V * * * n, i. 4r _ k___ _ l l 1 I FIG U RE 1 B. 1 ? Word processing software s whoping (or creating documentsthatconsistprimarily of text, but also lets youadd graphcs and sounds to your documents. It also provides layout births that letyou pay back brochures. newsletters,Web pages, and mom . 34 Chapter 1 M i 3 I H w fcn h Haw*M**AHa4M* M M ptflw W lM A to A M Ih m k B m V Dmm*mS. xa NvMrHtwMMk M r itM m i l h M ld * llh i f c n 1 ilfilw n TW t iW * * lW fa m i w d p u l n le y d w t t i i w l a Ml M l * * -1________________________B lw f lja ______ .. C uitrom A K lM M T . U . ATTOOCTBATLAW nose fuckdy2 AIMMBSB8ZT sunu,iL4nw C i A Urheborrechtlich geschOtztes M effigy 1B. 18 T oil rtyt Sj fca f Presentation software is mostoften used torcreating sales presentations,aXtvxjgh I mountain be effectivetorany typeol electronicside show. H i n X iM . i W hi V J i 1 jwufinm . H o? drrnfi Viis,-S* The Keyboard The Mouse Variants of the Mouse Ergonomics and Input Devices Lesson 2B Inputting D ata In O ther W ays Devices for the Hand Optical Input Devices Audiovisual Input Devices LESSON v m Over stare T he K eyboard an d M ouseIf you think of the CPU as a computers brain, whence you might think of the remark de vices as its sensory organsthe eyes, ears, and riffles. From the users organise of view, insert devices are just as important as the CPU, perhaps even more important. After you buy and set up the com* putcr, you may take the CPU for granted because you interact right away with stimulation devices and only indirectly with the CPU. But your ability to use excitant devices is critical to your overall triumph with the whole system. An commentary device docs exactly what its name suggests it enables you to enter information and needs into the computer. The most com* monly used input devices arc the make outboard and the creep.If you buy a new personal computer today, it w ill include a primalboard and slip un less you specify otherwise. Other types of input devices arc available as well, such as variations of the lift and specialized alternative input devices such as microphones and s contributeners. This lesson introduces you to the find outboard and the swipe. You w ill learn the richness of these devices, the way the computer accepts input from them, and the many tasks they enable you to perform on your PC. Using the Keyboard and Mouse OBJECTIVES individualism the volt differentiate groups on a standard computer backboneboard. Name six special*purpose spots found on all standard computer let outboards. run the steps a computer follows when pass judgment input from a keyboard. Describe the purpose of a black eye and the rote it plays in computing. Identify the five essential techniques for victimisation a fawn. Identify three common variants of the reversal. Describe five steps you can take to avoid repetitious sieve injuries from computer use. Urheberrechtilch g eschutztes Material The Keyboard O N L IN E For mote information on computer-based keyboard tutooals, vs* http//wvrw. mhho. com/ petemortoa The keyboard was one of the basic peripherals to be used with computers, and it is unperturbed the primary input device f or entering text and numbers. A standard keyboard includes about 100 keys some(prenominal)ly key sends a different contract to the CPU.If you have not used a computer keyboard or a typewriter, you w ill learn chop-chop that you can use a computer much more effectively if you know how to type. The accomplishment of typewriting, or keyboarding, is the ability to enter text and numbers with skill and accuracy. Certainly, you can use a computer without having fair typewriting skills. Some people claim that when computers can interpret mitt and speech with 100 percent accuracy, typing w ill become unnecessary. But for now and the foreseeable future, keyboarding remains the most common way to enter text and other data into a computer The Standard Keyboard Layout O N L IN E For more miormaiion on computer keyboards and keyboard manufacturers, visit http//www. mhhc. com/ petemortal Keyboards come in many styles.The sundry(a) models differ in surface, shape, and feel ask out for a few special-purpose keys, most keyboards arc fixed out almost identi cally. Among IBM-compatible computers, the most common keyboard layout is the IBM raise Keyboard. It has about 100 keys arranged in five groups, as shown in realize 2A. 1. (The term IBM-compatible computer refers to any PC based on the beginning(a) personal computers, which were made by IBM . Today, an IBMcompatible PC is any PC other than a Macintosh computer. ) The alphamericalal Keys The alphamerical keys(he land of the keyboard that looks bid a typewriters keysare arranged the same way on almost every keyboard.Sometimes this com mon arrangement is called the Q W ERTY (pronounced KWER-tcc) layout be cause the first six keys on the top row of letters are Q, W, E , R , T, and Y. a recollective with the keys that produce letters and numbers, the alphanumeric key group includes four keys having specific functions. The t a b , CAPS LOCK, ba c k spa c e , and e n t e r keys are described in hear 2A. 2. pr oject 2A . 1 Most BM com pattie PCs use a keyboard comparable M s one. Mar/ keyboards ingest a number of specialized keys, am)keyboardscan switch in sizing and shape. But nearly e l standard PC keyboards include the keys shewn here. The auto-changer Keys The SHIFT, ALT (Alternate), and CTRL ( reign) keys are called modifier keys be cause they modify the input of other keys.In other words, if you affirm agglomerate a modifier key musical composition air hugure another key, then you are changing the second keys Alphanum keys eric 50 Chapter 2 Theto key m ovesyouto predefined tabstops In m applicationprogram any s (suchas wordprocessors). Thebackspace keyerases addresss youhavejusttyped. Forexam ina ple, word processingprogramyoucan stuff baosmce to backover an In veracious character anddelete it Thecaps discard keylets youlock* the alphabetkeys sotheyproduceonly capital letters. The ehter key letsyou finalize dataentry inm typesof appBcatkmprogram any s. Ybualso can usew tw tocboosecom ands m andoptionsin m program and at any s various places in anoperatingsystems Interface. numeral 2A . 2 nput in some way. For example, if you press the Jtkcy, you input a small letter/. But if you hold down the sh u t key while urgent the J key, you input a capital /. M odifier keys arc utmost(a)ly useful bccausc they ease up all other keys bigeminal ca pabilities. Figure 2A. 3 describes the modifier keys and their uses. Functionsofthe tab,catsloo. v o s ta , andtwin keys The Numeric Keypad The numeric keypad is commonly located on the right side of the keyboard, as shown in Figure 2A. 1. The numeric keypad looks like a calculators keypad, with its 10 digits and mathematical operators (+, -, *, and Whenpressa gigantic with analphanumerickey,smft forcesthe /).The numeric keypad also stimulates a NUM computerto outputa capital letterorsymbol sun is also a LOCK key, which forces the numeric keys to in m ocfifierkey in someprogram forexam youcan presssnft s ple, put numbers. When NUM LOCK is deactivated, a achewtthcursor-m ovem keys toselect textforediting. ent the numeric keypads keys perform cursormovement control and other functions. The Function Keys The function keys, which are labeled F l, f l, and so on (as shown in Figure 2A. 1), are usu ally arranged in a row a farsighted the top of the key board. They allow you to input commands without typing long strings of characters or navigating menus or talks boxes. Each func tion keys purpose depends on the program you are using. For example, in most programs, F l is the help key. When you press it, a special window appears to display information about = OnThecm (control) key producesdifferent exits dependingonthe programyouare using. In m Windows-based program any s, cm-key combinationsprovide crosscuts for m com ands. Forexam the enu m ple, combinationcnuo enables youto rotate a newfile. n Them j (mjcmmu) keyoperates Skethectrl key,but producesa different set of results. In Windowsprog ram Mi-key s. combinations enableyouto navigate m enus anddialog boxeswithoutusingthe m ouse. course 2A . 3 Fuvtionsoftheshft, emuanda lt keys. Interacting with Your Computer 51 the program you are using. Most IBM-compatible keyboards have 12 function keys. some programs use function keys along with modifier keys to give the func tion keys more capabilities. The Cursor-Movement KeysMost standard keyboards also include a set of cursor-movcmcnt keys, which let you move around the screen without using a reverse. In many programs and op* erating systems, a mark on the screen intimates where the characters you type w ill be entered. This mark, called the cursor or origination leg, appears on the screen as a blooming(a) vertical line, a small box, or some other symbol to show your place in a document or command line. Figure 2A. 4 describes the cursor-movcmcnt keys and Figure 2A. 5 shows an insertion point in a document window. Special-Purpose Keys In entree to the five groups of k eys described earlier, all IBM*compatible key boards feature six special-purpose keys, each of which performs a odd func tion. Figure 2A. describes these spccial-purposc keys. Since 1996, nearly all IBM-compatible keyboards have include two additional special-purpose keys knowing to work with the Windows operating systems (see Figure 2A. 7) start . This key, which features the Windows logotype (and is sometimes called the Windows logo key), devotes the Windows Start menu on most computers. bear oning this key is the same as wienerwursting the Start exit on the Windows task deflect. s h o r t c u t . This key, which features an image o f a menu, opens an on-screen shortcut menu in Windows-based application programs. wizard of the latest trends in keyboard technology is the addition of Internet and multimedia controls.Microsofts Internet Keyboard and MultiMedia Keyboard, for example, feature but oodles that you can program to perform any number of tasks. For example, you can use the press releases to prepare a Web browser, specify e-mail. Depending onme program,you maybe able to press nomcto movethe cursorto the beginning ofa line and brto moveto the endof a line. The mccu and hm o o w keys let you flip p * through a document, screen by screen, Hto turning the pages of a book. Press m et w to lump to the previous screen press m gedonn to jump to the next ___ I The arrow keys move the insertion point up or down a single line, or left over(p) or right one character space. opine 2A . 4 The airsor-movement keys. sort 2A . Thecursor, orinsertionpoW, shews wherethenextletter typedwit appear. 52 Chapter 2 The cursor, o r insertion point, in a document eberrechtlich M The(softkeys functiondependsonyour programoroperatingenvironment Typically, the csckeyis usedtobackuponelevel in a multilevel environm ent. ThenmT scREBtkey sRom the user10 s capture whatever b shownon thescreen as anim Thiskeydoes notwork with al age. program s. In som programs,scrou. lock causes the e cursorto remain unmoving onthescreen, andthe documentscontentsm aroundIt. ove Thiskeydoesntfuncttonatal in som program e s. In som programs,themuse key can b e e usedtostopa co m In progress. m and 1 5 M i I I I ? . a . 5 is Bill r I I* JTheM keyBatches som programsfrom SEm e Insert m ode (in wtiich textis inserted into thedocum at the cursor) toovertypem ent ode (in whichnewtextis typodover existingtext), andvice vena. m N A 4 f I 6 m n ? 6 a ? 3 i* J removesonecharacterat a time at thecursors location, cam erases characterstothe right otthecursor. FIGURE 2A . 6 SpecU jwpose keysonm standard ost keyboards FIGURE 2A . 7 ThosafiT keyandtheatofiran rook appear frequencyontherwwer keytnordsthat are sdldwAhWndcMiS basedcom puters. 2Z and start your most oftentimes used programs. Multimedia clits let you control the computers CD-ROM or DVD drive and adjust the speaker volume. many an(prenominal) key* board makers offer such features on newer models (see Figure 2A. 8) . How the Computer Accepts Input from the KeyboardYou might think the keyboard hardly sends the letter of a pressed key to the computer by and by all, that is what appears to happen. Actually, the process of ac cepting input from the keyboard is more complex, as shown in Figure 2A. 9. When you press a key, a tiny chip called the keyboard ascendance notes that a key has been presxd. The keyboard controller places a code into pan of its memory. Interacting with Your Computer 53 B i f a S Q ill FIGURE 2A. 8 called the keyboard damp, to indicate which key was pressed. (A buffer is a tem porary storage theater of operations that holds data until it can be processed. ) The keyboard con banal on newer keyboards. roller then sends a signal to the computers system software, notifying it that something has happened at the keyboard. Q A key is pressed onthe keyboard When the system software receives the signal, it determines the appropriate response. When a keystroke has occurred, the sys tem reads the Q Thesystemsoftwareresponds to memory location in the keyboard He Interruptby indicant thescan code fromthe keyboardbuffer. buffer that contains the code of the key that was pressed. The sys K EYBO RD A SYSTEM tem software then passes that fan SOFTWARE code to the CPU. 0 The keyboard controler e The keyboardcontroller The keyboard buffer can store Q The system software sends an agitate sendsDiescan code passes the scan code many keystrokes at one time.This request to the forthe key tothe tothe CPU strength is necessary because keyboardbuffet system software. some time elapses between the mechanical press of a key and the com FIGURE 2A. 9 puters reading of that key from the keyboard buffer. W ith the key How Input is recawd from the keyboard strokes stored in a buffer, the program can react to them when it is convenient. O f course, this all happens very apace. Unless the computer is very busy handling multiple tasks, you notice no delay between pressure sensatio n keys and seeing the letters on your screen. In some computers, the keyboard controller handles input from the computers keyboard and cabbage and stores the settings for both devices.One keyboard set ting, the repeat rate, determines how long you must hold down an alphanumeric key before the keyboard w ill repeat the character and how rapidly the character is retyped while you press the key. You can set the repeat rate to suit your typing speed. (You w ill learn how to check your keyboards repeat rate in the lab exer cises at the end of this chapter. ) internet and muftmeda features are The Mouse A personal computer that was purchased in the early 1980s probably included a keyboard as the only input device. Today, every new PC includes a pointing dcvicc as standard equipment, as shown in Figure 2A. 10. Full-size PCs usually include a hook as the pointing dcvicc.A shiner is an input dcvicc that you can move around on a flat surface (usually on a desk or keyboard tray) and controls the cursor. The cursor (also called the swipe cursor) is an on-screen object, usually an arrow, that is used to select text access menus and interact with programs, files, or data that appear on the screen. Figure 2A. 11 shows an example of a arrow in a program window. FIGURE 2A. 10 Most modern personal computers are eqlipped w ti a mctse. 54 Chapter 2 The mechanical mouse is the most common type of pointing de vice. A mechanical mouse contains a small rubber thud that proW trades through a hole in the bottom of the mouses. case (see Figure 2A. 12). The ball rolls inside the case when you move the mouse around on a flat surface.Inside the mouse, rollers and sensors send signals to the computer, telling it the distance, direction, and speed of the balls motions (see Figure 2A. 13). The computer uses this data to position the mouse pointer on the screen. Another popular type of mouse, the optical mouse, is nonmechanical. This type of mouse emits a beam of light from its nates it uses the lights reflection to judge the distance, direction, and speed of its travel (see Figure 2A. 14). The mouse offers two main benefits. First, the mouse lets you position the cur sor anywhere on the screen quickly without using the cursor-movement keys. You simply move the pointer to the on Rdlers screen position you want and press the mouse handout the cursor appears at that location.Second, instead of forcing you to type or issue commands from the key board, the mouse and mouse-based operating systems let you postulate com mands from easy-to-use menus and dialog boxes (see Figure 2A. 15). The result is a much more intuitive way to use computers. Instead of re elementing obscure command names, users can figure out rather intimately where com mands and options arc located. FIG U R E 2A. 11 Anexam ola pointeras it m ple ight appearona com puterscreen. o r f f c iN E For m Inform ore ationonm ice andm ousemanufacturers,vsil http//www. mhhe. com/ petemoiton. FIGURE 2 A . 1 2 The partofa mechanical m ouse,seen fro Vieb m m otto . NortO N L IN E Formoreformation onoptical mice, visit http//wvrw. mhhe. com/ petemorion Q Whenthe mouse mom he rolling mouse bail spins me rollers Q Thertormafa i from the reel roMereIs sent to the system software,wNcti controls the pointer. FIGURE 2A. 13 H them ow ousecontrolsthepointer. Interacting with Your Computer 55 1 Urheberrechtlich geschi i FIGURE 2A. 14 The underside ol anoptical mouse. If you use a drawing program, you can use the mouse to crcatc naturals such as lines, curves, and freehand shapes on the scrccn. The mouse has helped clear the com* purer as a versatile tool for graphic designers, starting w hat has since bccome a revolution in the graphic de* sign field. Using th e Mouse For more MormaUcn on mouse techniques, w sl http//www. mhhe. com/ petemortonYou use a mouse to move the pointer to a location on the screen, a process called pointing. Everything you do with a mouse is polished by com bining po int ing w ith these techniques Clicking Double-clicking Dragging Right-clicking FIGURE 2A. 15 Using the mouse to choose a command Irom a menu. r*e Cdt ym ?exh ? o fcsownarks Ctrl+N ( New U*vn)4lCir SVQctow N& *I Ofwn Web Location CtrHSMt+l Qpen Fie 0 SM CblfO Qrl+W OrM-S CdtPaga Send Page OrU Q rffP Print P is WoifcCffine _ fe t Q jW 1 Pointing means pushing the mouse crosswise your desk. O n the scrccn, the pointer moves in relation to the mouse (see Figure 2A. 16).Push the mouse forward, and the pointer moves up. Push the mouse to the left, and the pointer moves to the left. To point to an ob ject or location on the scrccn, you simply use the mouse to place the pointer on top of the object or location. The mice that come w ith IBM-compatible computers usually have two buttons, but tech niques such as clicking, double-clicking, and puff upging arc usually carried out w ith the left mouse button (see Figure 2A. 17). In m ulti button mice, one button must be designated FIGUR E 2A. 16 Using the mouse to control the on-screen pointer. The pointer moves in relation tothe mouses movements. 56 Chapter 2 Urheberrechthch geschutztes Ma s the primary button, re InWindows and m any The left mouse button Windows programs, the ferred to as the mouse button. is usualy the primary right mouse button Some mice can have three or button. can be used in more buttons. The buttons manyways, too. uses arc determined by the computers operating system, application software, and mouse-control software. To click an souvenir w ith the mouse, you move the pointer to the distributor point on the scrccn. When the pointer touches the object, quickly press and blowhole the primary mouse button once d c k see Figure 2A. 18). Clicking or single-clicking, as it is also called is the most important mouse action. To select any object on the screen, such as a menu, com mand, or button, you click it.Double-clicking an degree means pointing to the item with the mouse pointer and then p ressing and releasing the mouse button in two ways in rapid succession (see Figure 2A. 19). Double-clicking is prim arily used with desktop objects such as tropes. For example, you can double-click a pro click click grams icon to ground the program. Dragging an item means billet the mouse pointer over the item, pressing the primary mouse button, and holding it down as you move the mouse. As you move the pointer, the item is comfortged along with it across the scrccn (see Figure 2A. 20). You can then drop the item in a new position on the screen. This technique is also called drag-and-drop editing, or just drag and drop. Dragging is a very handy tool.In a wordprocessing program, for exam -and release the button ple, you can drag text from one Hold down the when you finish dragging. primary button 4 location to another in a docu a s you move ment. In a file-managemcnr th e m o u se.. program, you can drag a docu ments icon and drop it onto a printers icon to print the docu ment. W indows and many W in dows programs agree rightclicking, which means pointing to an item on the screen, then pressing and releasing the right mouse button (see Figure 2A. 21). Right-clicking usually opens a shortcut menu that contains commands and options that fix to the item to which you arc pointing.A wheel mouse has a small wheel nestled among its but tons (see Figure 2A. 22). You can use the wheel for various purposes, one o f which is scrolling through long docu ments. N ot all applications and operating systems support the use o f the wheel. FIGURE 2A. 17 Standardbutton bod ona tw obuttonmouse. FIGURE 2A. 18 Clicking a mouse. FIGURE 2A. 19 DoUbie-dlcWnga mouse. FIG URE 2A. 20 Bragging with a mouse. FIG URE 2A. 21 RiQht-dictonga mouse. Interacting with Your Computer 57 U rheberrechtlich g esch u tz tes al Nor Mouse Button Configurations m IN E For m tatorm ore atJononthecare andusageofrrtce. visit http//www. mhhe. com/ pctemorton FIGURE 2A. 22 Avrfieel mouse.The mouse usual ly sits to the right of the keyboard (for right-handed people), and the user maneuvers the mouse with the right hand, pressing the left button with the right forefinger. For this reason, the left mouse button is sometimes called the primary mouse button. If you are left-handed, you can configure the right mouse button as the primary button (as shown in Figure 2A. 23). This descriptor lets you place the mouse to the left of the keyboard, control the mouse with your left hand, and use your left fore* finger for most mouse actions. Newer mice enable you to configure buttons to perform different tasks than clicking. You might configure a button to delete selected text, for ex ample, or to open a program that lets you search for files.Such settings may lim it the usefulness of the mouse but can be helpful if you need to perform a certain task many times. m 3 MWwaauMOUl Variants of the Mouse Although the mouse is a handy tool, some people do MMbi not like using a mouse or have gruelli ngy maneuvering 1(0* one. For others, a mouse W D i W tfW w requires too much desktop jo* spacea genuine problem when you are not working at a deskl Uw aJi tM For these reasons and others, hardware makers have real devices that Cm * k 1 m * 1 duplicate the mouses func tionality but interact with the user in different ways. The primary goals or these mouse variants* are to provide case of use while pickings up less space than a mouse.They all remain sta tionary and can even be build into the keyboard. Trackballs A atomic number 82ball is a pointing device that works like an upside-down mouse. You rest your index finger or thumb on an exposed ball, then place your other fingers on the buttons. To move the pointer around the screen, you roll the ball with your in dex finger or thumb. Because you do not move the whole device, a trackball re quires less space than a mouse. Trackballs gained popularity with the advent of laptop computers, which typically are used on laps or on sm all work surfaces that have no room for a mouse. Trackballs come in different models, as shown in Figure 2A. 24.Some track balls are large and heavy with a ball about the same size as a cue balL Others are much smaller. Most trackballs feature two buttons, although three-button models http//www. mhhe. com/ pctemorton 58 Chapter 2 Urheberrechlllch geschOtztes Ma SELF-CHECK racing circuit the correct answer for each question. 1. Themost com onkeyboard layout hasabout this manykeys. m a. 10 a. s t/ h i k e y h. 100 b. sh o rtc u t k e y c. 110 c. a lte rn a je key IB il 2. Wfochspecial keyboardkey has a picture of theWindows logoonit? 3. Most full-si2e PCs feature oneof these as the pointingdevice. a. Keyboard b. Mouse c. Scanner p w are also available. Trackball units also are available in right- and left-handed models. TrackpadsThe trackpad (also called a touchpad) is a stationary pointing device that many people find less tiring to use than a mouse or trackball. The movement of a finger across a small touch-sensitive surface is translated into pointer movement on the computer screen. The touch-scnsitivc surface may be only 1. 5 or 2 inches square, so the finger never has to move far. The trackpads size also makes it adequate for a notebook computer. Some notebook models feature a create-in trackpad rather than a mouse or trackball (sec Figure 2A. 25). Like mice, trackpads usually are separate from the keyboard in desktop com puters and are connected to the computer through a cord.Some special keyboards feature built-in trackpads. This feature keeps the pad handy and frees a port that would otherwise be used by the trackpad. Trackpads include two or three buttons that perform the same functions as mouse buttons. Some trackpads arc also strike sensitive, meaning you can tap the pad with your fingertip instead of using its buttons. FIGURE 2A. 24 Trackballscomeinm shapes and any sires. Form infcxm on ore ailon tracl ad andintegrated p s porting devces. vis * http//www. mhhe. com/ petemorton arrows in the Keyboard Many portable computers now fea ture a small joyousnessstick positioned near the nerve centre of the keyboard, typically between the G and H keys.The joy stick is controlled with either fore finger, and it controls the movement of the pointer on screen. Because users do not have to take their give off the keyboard to use this device, they can save a great deal of time and effort. dickens buttons that per form the same function as mouse buttons are just beneath the space bar and are pressed with the thumb. Several generic scathe have emerged for this device many manu facturers refer to it as an integrated FIGURE 2A. 2S Trackpad Soma notebookcomputersanddesktop keyboardsfeatire a buiK-intraefcpod Interacting with Your Computer 59 M , I Pmdunthvily Tip speech Tim e With Keyboard ShortcutsIn the 1980s, as programmers began packing more features into PC software, they also developed ways for users to is sue an ever-increasin g number of commands. Software packages came with long lists of commands, all of which had to be entered at the keyboard. (This was before the mouse came into common use. ) As a result, the computer keyboard rapidly became a valuable tool. Programmers began create mentally keyboard shortcuts that allow users to issue commands quickly by typing a short combination of keystrokes. Keyboard shortcuts involve using a modifier key (such as aut or cm. ) along with one or more alphanumeric or function keys. To print a document in many applications, for example the user can press ctri+p.Function keys also became important The Fl key, for ex ample, became the comprehensive way to access online help. IBMcompatible computer keyboards originally had 10 function keys eventually the number of function keys was expand to 12. Another common type of keyboard shortcut involves pressing the a u key to access a programs menu system. When running any Windows program, you can press alt to activate the m enu bar, and then press a highlighted letter in a menus name to open that menu. Stilt a keyboard can hold only so many keys, and the lists of keyboard shortcuts became unmanageable. A single program could use dozens of hotkeys, as these shortcuts were called. If you used several programs, you had to learn different shortcuts for each program.Finally, the commonplace User Access (CUA) standard led to the standardization of many commonly used hotkeys across different programs and environments. With this standard for commonly used hotkeys, users have less hotkeys to remember. Despite such standards, pointing devices (such as the mouse) came along none too soon for hotkey-weary com puter users. Microsoft Windows and the Macintosh operating system gained popularity because of their easy-to-use, mouse-oriented graphical interfaces. By operating the mouse, users could make selections visually from menus and dialog boxes. Emphasis rapidly began shifting away from the keyboard to the scre en today, many users do not know the purpose of their function keys pointing dcvicc, while others call it a 3-D point stick.On the IBM ThinkPad line of notebook computers, the pointing device is called the TrackPoint (see Figure 2A. 26). Ergonomics and Input Devices Any officc actor w ill tell you tliat working at a desk all day can be extremely uncomfortable (see Figure 2A. 27). Sitting all day and us ing a computer can be even worse. Not only docs the users body ache from being in a death chair too long, but hand and wrist injuries can result from using a keyboard and mouse for long periods. Eyes can become strained from ever netting(a) at a monitor for hours. Such injuries can be extreme, threatening the users prevalent health and ability to work. Much is being done to make computers easier safer, and more comfortable to use.Ergonomics, which is the study of the physiological relationship between people and their toolssuch as computers addresses these issues. Now more than ev er before, people contend the impor tance of having ergonomically correct computer furniture and using square-toed posture and techniques while working with computers. (The term ergonomically correct means that a tool or a workplace is designed to work properly with the tender-hearted body, and thus reduces the risk of strain and injuries. ) TrackPoint FIG U RE 2A. 26 IBMs ThinkPad computers feature the TrackPoint pointing device, and smtar donees are found in many otter portable PCs. 60 Chapter 2 Press cm+a To Toggle brusk character data change on or off for the selected or inserted ext make letters bold or unbold Toggle italic character formatting on or off for the selected or inserted text make letters italic Toggle underline character formatting on or off for the selected or inserted text underline letters Oecrease font size for the selected or inserted text Increase font size for the selected or inserted text Remove split up formatting for the selected dissever or parag raphs Remove character formatting for the selected text Copy the selected text or object Cut the selected text or object counterpane text or an object Undo the last action Redo the last action c tilh Pointing, however, can slow you down. As menus and di alog boxes become increasingly crowded, commands can be hard to find and their locations can be as difficult to re member as keyboard shortcuts. Many computer users over come these problems by using a combination of keyboard shortcuts and a pointing device. You use one hand to issue many basic shortcuts (such as cnti+f and ctrl+s) or to launch macros. A macro is a series of commands that a pro gram memorizes for you. Macros enable you to issue an en tire set o t commands in just a few keystrokes.Using these techniques minimizes keystrokes and leaves a hand free to use a pointing device. The following table lists some of the shortcut keys avail able in Microsoft Word. ctri-hi ctm shift* ctl+shih+ CTRi+o ctri+smcebar cm -K ctri+x ctri +y ctri+z ctrl+ y Repetitive nisus Injuries The field of ergonomics did not rcccivc much vigilance until a ccrtain class o f in juries began appearing among clerical workers who spend most o f their time en tering data on computer keyboards. These ailments are called repetitive pains injuries (RSIs) or repetitive strain injuries and result from continuously using the body in ways it was not designed to work.One type of RSI that is especially well documented among computer users is wrist bone bone turn over syndrome, a wrist or hand in jury caused by using a keyboard for long periods of time. W C IW E For moreinformationon ergonomics andavok&ig computer-relatedinjuries, v a i http//www. mhhe. conj/ petemorton FIGURE 2A. 27 Experience showslhat seat worftcan pose speofc healti risks. Interacting with Your Computer 61 Urheberrechtlich geschulzles M transverse Cross Section of NormalW rit FlexorTendons and Sheath . . Inflamed Inflamedtendon typeface presses against median nerv e carpal?. * Bones FIGURE 2A . 2 8 Carpel cut into syndrom requiresthe e nervesrunningthroughthe carpal tunnel of thewrist. The carpal tunnel is a highway in the wrist through which nerves pass (see Figure 2A. 28).In carpal tunnel syndrome, tendons in the tunnel bccome inflamed because the victim has held his or her wrists stiffly for long periods, as people tend to do at a keyboard. When the tendons become inflamed, they press against the nerves, causing tingling, numbness, pain, or the inability to use the workforce. Carpal tunnel syndrome is the best(p)-known repetitive stress injury. It can become so de bilitating that victims can miss weeks or months of work. In extreme cases, surgery is required. averting Keyboard-Related Injuries If you use a computer frequently, you can avoid RSIs by adopting a few nice work habits, and by making sure that your hardware and workspace are set up in an ergonomically favourable way. At Jssue Com puter Voting Is It a Good affaire?The dispute over electronic voting is as heated as a debate between presidential candidates. The risks versus the bene fits are discussed, investigated, and argued. But what are the facts that lie beneath the fuss? The key function of an electronic voting system is to ob tain voter preferences and herald themreliably and accu rately. Some assert that electronic systems are safer than other methods of voting because they implement security checks and analyze trails, and are tougher to tamper with than paper ballots. One of the most widely used electronic voting systems. Diebold choice Systems (http//www. diebold. com/ dieboldes/accuvote_ts. tm), boasts some 33,000 voting stations in locations across the United States. Dieboltfs AccuVote-TS system is a voter-activated interactive touch screen system using an intelligent voter Card as the voter interface. The interface allows voters to view and cast their votes by touching target areas on an electronically gener ated ballot pad. Each un it provides a direct-entry computerized voting station that automatically records and stores ballot infor mation and results. firearm classified as a direct record entry (ORE) device, the AccuVote-TS system has additional capa bilities. The tabulator is a multifunctional interface that counts and abulates the ballots at precincts on election day and communicates with the host computer at Election fundamental for accurate and timely jurisdictionwide results. However, electronic voting systems have generated con cern because their work is not readily genial for inspec tion what goes on behind the screen is a brain-teaser to the general public and therefore causes uneasiness. With com puter voting, voter records are intangibly stored on a hard drive, with voting results save in electronic memory. Indeed, a July 2003 analysis of the Diebold touch screen by computer researchers from Johns Hopkins and Rice uni versities (found at http//www. newscientist. oin) showed that the software was riddled with errors and open to fraud. However, even with the speculation of fraud, electronic 62 Chapter 2 Urheberrechllich oesch When setting up your computing workspace, make it a earlier ity to choose a comfortable, ergonomically designed chair (sec Figure 2A. 29). Your chest of drawers chair should Allow you to adjust its height. Provide in effect(p) lower-back support. Have adjustable armrests. Your desk also should be well-suited to computer use, like the one shown in Figure 2A. 30. The desk should hold your key board and mouse at the proper height, so that your workforce are at the same height as your elbows (or a few inches lower) when you hold them over the keyboard.Here arc some other tips that can help you avoid RSIs while working with your keyboard and mouse Use an Ergonomic Keyboard. Traditional, flat keyboards arc not well-suited to the shape of human hands. An ergonomic keyboard allows you to hold your hands in a more natural position (with wrists strai ght, rather than angled outward) while typing (see Figure 2A. 31). Use a Padded Wrist Support. If you type a lot, a wrist support can be helpful by allowing you to rest your hands comfortably when you are not actually typ ing. recover however, that FIGURE 2A. 29 Anergonom ically designedcom puter chairanddesk. FIGURE 2A. 30 A propertydesignedcom puterdesk featuresa Udl-insfieB or traytohoWffw keyteard andm ouse. ystems may still be safer than prior methods of voting be cause they implement additional security checks and audits and may be more difficult to tamper with because of the size and nature of their tabulating components. Another argument in favor of paper ballots, or at least paper receipts, is that in order to confirm an election, all you need to do is gather up the ballots and tabulate them a sec ond (or third, as the case may be) time. However, auditing paper ballot systems is not always as easy as it sounds. Bal lots, particularly punch-cards, sometimes provide ambigu ous results, as seen in a young presidential election. They are easily forged and they must be physically handled and transported, which provides the opportunity for substitu tion or loss.Whether computerized or traditional, no election system is infallible, and in truth, perhaps it doesnt need to be. As some have said, every safe has the capability to be cracked. The same is true for voting systems. The issue is not whether they are 100 percent secure, but whether they pre sent adequate safeguards to give us faith in the integrity of our elections. n Interacting with Your Computer 63 you should never rest your wrists on anythingeven a comfortable wrist supportwhile you type. Use the support only when your fingers are not moving over the keyboard. Keep Your Wrists Straight. When typing, your hands should be in a straight line with your forearms, when viewed either from above or from the side (see Figure 2A. 32).Keeping the wrists bent in cither direction can cause mus de fatig ue. Sit Up Straight. Avoid slouching as you type, and keep your feet flat on the report in front of you. Avoid crossing your legs in front of you or under your chair for long periods. Learn to Type. You w ill use the keyboard more efficiently and naturally if you know how to type. If you M melt down and peek, you are more likely to slouch and keep your head down while looking at rite keyboard. This tech nique not only slows you down, but it leads to fatigue and stiffness. Take Frequent Breaks. Get up and move around for a few legal proceeding each hour, and stretch occasionally throughout the day. FIGURE 2A. 31Anexam ol anergonom keyboard. ple ic FIGURE 2A. 32 Whent in . your handsshouldbein pg & eWin yourforearm al all tonesand n s whenviewedfromanyantfe. 64 Chapter 2 Urheberrechlllch geschutzte appraise Summary A standard computer keyboard has about 100 keys. Most keyboards follow a similar layout, with their keys arranged in five groups. Those groups include the alphanumer ic keys, numeric keypad, function keys, mod ifier keys, and cursor-movement keys. When you press a key, the keyboard controller places a code in the keyboard buffer to indicate which key was pressed. The keyboard sends the computer a signal, which tells the CPU to accept the keystroke. The mouse is a pointing device that lets you control the position of a graphical pointer on the screen without using the keyboard. Using the mouse involves five techniques pointing, clicking, double-clicking, drag ging, and right-clicking. A trackball is like a mouse turned upside-down. It provides the functionality of a mouse but takes less space on the desktop. A trackpad is a touch-sensitive pad that provides the same functionality as a mouse. To use a trackpad, you glide your finger across its surface. Many notebook computers provide a joystick-like pointing device built into the keyboard. You control the pointer by moving the joystick.On IBM systems, this de vice is called a TrackPoint Gener ically, it is called an integrated pointing device. Continuous use of a keyboard and pointing device can lead to repetitive stress injuries. The field of ergonomics studies the way people use took. This study leads to bet ter product designs and techniques that help people avoid injuries at work. Ergonomically designed keyboards are available to help users prevent repetitive stress injuries to the wrists and hands. Key Terms alphanumeric key, 60 buffer, 54 carpal tunnel syndrome, 61 click, 57 cursor, 52 cursor-movement key, 52 double-clicking, 57 drag and drop, 57 drag-and-drop editing, 57 dragging, 57 ergonomics, 60 function key. 51 insertion point 52 integrated pointing device. 9 keyboard buffer, 54 keyboard controller, 53 keyboarding, 50 mechanical mouse, 55 modifier key, 50 numeric keypad, 51 optical mouse, 55 pointer, 54 pointing, 56 pointing device. 54 repeat rate, 54 repetitive stress injury (RSI), 61 right-dicking, 57 trackpad, 59 TrackPoint 60 wheel mouse, 57 Interactin g with Your Computer 65 Urheberrechtlich g esch u tztes M tLgg 8 0 K ey Term Quiz i Review Complete each statement by writing one of the terms listed under Key Terms in each blank. 1. In computer use, the skill of typing is often referred to as 2. IBM -com patible PCs have 10 or 1 2______________ keys. . 3. In many programs, an on-screen symbol called a(n )___________ or a(n )____________ shows you where you are in a document 4.A(n) is a temporary storage area that holds data until the CPU is ready for it. 5. In addition to pointing, the four primary mouse techniques are and___________ _ 6. You use a mouse (or one of its variants) to position a(n )_____ 7. In many Windows applications, you can open a shortcut menu by. on the screen. ______ the mouse. 8. Many laptop computers feature a small joystick between the c and k keys, which is called a(n) a(n )-9. is the study of the way people work with tools. 10. _____ is a common type of repetitive stress injury among computer users. Mul tiple Choice is Circle the word or phrase that best completes each statement. 1.Some people claim that when computers can interpret handwriting and speech with 100 percent accuracy, this will become unnecessary. a. mice a. special-purpose keys b. typing b. function keys c. pointing device c. typing keys layout. d. special-purpose keys d. alphanumeric keys d. QWERYT d. iadsmce 2. These keys make up the part of the keyboard that looks like a typewriters keys, 3. The common keyboard arrangement is called the a. QWERTY b. QEWTYR 4. Which of the following is not a modifier key? a. shift b. cm c. ait 5. In most programs, you can press this key to get help, a. csc a. keyboard a. C C S b. r l b. keyboard buffer b. f1 c . alt c . keyboard controller C. SM CEBAR d . no d. keyboard CPU d.S O T U H RCT 6. When you press a key, this device notifies the system software, 7. In many Windows applications, you can use this key as an alternative to the right mouse button. c. QYWERT 66 Chapter 2 Urh eberrechtlich geschutztes Material 8. This type of mouse uses reflected light to measure its movements. c. mechanical a. optical b. laser 9. In a multi-button mouse, one button must be designated as the c. primary a. first b. left 10. You can__ a. point to a programs icon to launch the program. b. double-click C. right-click button. d. user d. drag Review d. wheel Review Questions In your own words, briefly answer the following questions. 1.Host standard keyboards include five major groups of keys. List them. 2. Why are most standard keyboards called QWERTY keyboards? 3. What does the ctrl key do? 4. What is the purpose of the start key, which appears on many IBM-compatible keyboards? 5. What happens when you press a key on the computers keyboard? 6. What is the purpose of the mouse pointer? 7. How does a mechanical mouse work? 8. Describe two benefits of using a mouse. 9. What does the term dragging mean and how do you do it? 10. Describe the cause and effect of carpal tunnel syn drome. Lesson Labs Complete the following exercises as directed by your instructor. 1. Test your typing skills in Notepad.Click the start button, point to All Programs, click Accessories, and then dick Notepad to open the Notepad text-editing program. Notepad opens in a window. Have a schoolmate time you as you type a paragraph of text. The paragraph should be at least five lines long and should make sense. (For example, you could type a paragraph of text from any page in this book. ) Do not stop to correct mistakes keep typing until you are finished typing the selection. 2. Inspect your systems mouse settings. (Do not change any settings without your instructors permission. ) Use the following steps a. Click the start button to open the Start menu then click Control Panel.The Control Panel window opens. b. Double-dick the Mouse icon to open the Mouse Properties dialog box. Click the tabs in this dialog box and inspect your settings. c. Experiment with the Pointer Speed and Show P ointer Trails tools. How do they affect your mouses performance. When you are finished, dick Cancel Interacting with Your Computer 67 M U R B Overview O ptions for Every N eed a n d P referen c e Although the keyboard and the mouse arc the input dcviccs that people use most often, there are many other ways to input data into a com puter. Sometimes the tool is simply a matter of choice. Some users jusr prefer the feel of a trackball over a mouse.In many cases, however, an banausic input device may nor be the best choice. In a dusty factory or warehouse, for example, a standard keyboard or mouse can be dam* aged if it becomes clogged with dirt. grocery store checkout lines would slow down dramatically if cashiers had to manually input product codes and prices. In these environments, specialized input devices tolerate extreme conditions and reduce the risk of input errors. Alternative input devices are important parts of some specialpurpose computers. Tapping a handheld computers scr ccn with a pen is a much faster way to input commands than typing on a miniature key board. On the other hand, a specialized device can give new purpose to a standard system.If you want to play action-packed grittys on your home PC, for example, you w ill have more fun if you use a joystick or game controller than a standard keyboard or mouse. This lesson examines several categories of alternative input devices and discusses the special uses of each. You may be surprised at how of ten you see these devices, and yo