Introduction to Computers by Peter Norton 6th Ed

Q e SPECIAL INDIAN EDITION J S ix t l d it io n INTRODUCTION 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 unless Uploaded By M. Kamran Hanif E-mail mk. emailprotected com Website www. kamran. hk. ms Information contained in this work has been obtained by Tata McGraw-Hill, from sources believed to be reli able.However, incomplete Tata McGraw-Hill nor its authors guarantee the accuracy or com pleteness of every infor mation published herein, and neither Tata McGraw-Hill nor Its authors shall be responsible for any errors, omissions, or damages arising out of use of this Infor* mation. This work is published with the understanding that Tata McGraw-Hill and its authors ar supplying in formation plainly be not attempting to render engineering or some new(prenominal) professional services. If such services are re quired. the assistance of an appropriate professional should be sought m Tata McGraw-Hi llPET ER NORTONS * INTRODUCTION TO CO M PUTERS Indian Adaptation d peerless and scarcely(a) by arrangement with the McGraw-Hill Companies Inc.. juvenileYbrk Sales territories India. Pakistan, Nepal, Bangladesh, Sri Lanka and Bhutan. Ninth reproduce 2008 RYXDCDRXRB8YA Copyright (D 2006 by The McGraw-Hill Companies, inc. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval st charge per unitgy, without the prior written consent of The McGraw-Hill Companies, Inc.. including, but not limited to, in any network or new(prenominal) electronic storage or transmission, or broadcast for distance learning. any(prenominal) andllaries, including electronic and print components, may not be available to customers outside the fall in 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 110 008. sheathset m Tim es at Script Makers. 19, A1-B. DDA Market, Pashchim Vlhar, New Delhi 110 063 and printed at Pashupati Printers, 1/429/16, G ali No. 1, Friends Colony. G. T. Road, Shahdara, Delhi 110 095 Cover Printer SD R Printers Cover Design Kapil Gupta The M cG raw -H ill Contponies Ez& sscr PH M TPM TQ AT A Cl IWindows 7 Check Your UnderstandingChapter 1 Introducing reckoner Systems Lesson 1A Exploring calculators and Their Uses Lesson IB Lookina Inside the Computer Svstem Chapter 2 Inter execute with Your Computer Lesson 2A utilize the Kevboard and reversal Lesson 2B Inputting Data in Other Wavs Chapter 3 Secinq, Hearing, and Printin) Data lctnn 3A Virfpo and Snunri Lesson 3B Printinq Chanter 4 Processing Data Lesson 4A Transfbrmina Data into Information Lesson 4B Modem mainframes Chapter 5 Storina Data Lesson SA Types of Storaqe Devices Lesson SB Measurinq and Improving Drive Performance Chapter 6 Usina Ooeratinu Systems Lesson 6A Oporatinq Svstem Basics lesson 6B Survev of PC nd Ne twork Operatino Systems Chanter 7 Net plant Lesson 7A Networkinq Basics 2 3 24 48 49 68 88 89 1 07 124 12S Ufi m m 107 Chapter 0 Working in the Online creation Lesson 9A Connectinq to the meshwork Lesson 9B Doinq Business in the Online World Chapter 10 Workinq with practise software product Lesson 10A Productivity Software Lesson 10B Graphics and Multimedia Chapter 11 Database Management Lesson 11A Database Manaqement Systems Lesson 11B Survey of Database Systems Chanter 12 Software Proaramminq and Development Lesson 12A Creating Computer Proqrams Lesson 12B Proaramminq Lanauaoes and the Proqramminq Process Chanter 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 Appendix A Creating Your Own Web Paae 22k Appendix B Buyinq Your First Computer 242 Appendix C Computer Viruses Annendix D History of Micro computing machines 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 Services 284 286 312 Urheberrechtlich geschutzies aterial FEATURE ARTICLES At Is sue 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 Keyboard Shortcuts The fear and Feedinq of Printers Do You Need M n RAM? Backino Up Your Data Do-It-Yourself Tech Support The Telecommuters Checklist- Evaluatino the Reliability of Search Results and Web Sites Sharinq an Internet linkup Automatinq Your Work with Macros 0atahaoard, swipe,and microphone are commonInputdevices. Microphone Keyboard Speakers Monitor Printer formURE 1B. 11 Themonitor, primer,and speakers are commonou? put devices. 30 Chapter 1 Some types of to a great extentware grass act as some(prenominal) enter and output devices. A touch screen, for example, is a type of monitor that displays text or icons you gouge touch. When you touch the screen, special(prenominal) sensors detect the touch and the figurer cal culates the point on the screen where you placed your finger.Depending on the lo cation of the touch, the electronic computing machine determines what information to display or what action to take next. communications devices are the dependable about common types of devices that outhouse per form both arousal and output. These devices connect one calculator 10 anothera process know as net working(a). The close to common kinds of communications de vices are modems, which enable computers to communicate through with(predicate) telephone lines or cable television systems, and network interface tease (NICs), which let substance ab exploiters connect a group of computers to share data and devices. memory Devices A computer sess character with only processing, stock, insert, and output de vices.To be truly useful, however a computer too needs a place to take hold computer courseme files and related data when they are not in use. The pop the question of storage is to rent data permanently, even when the computer is turned off. You may think of storage as an electronic file cabinet and RAM as an elec tronic worktable. When you need to work with a platform or a set of data, the computer locates it in the file cabinet and puts a copy on the table. by and by you kick in finished working with the program or data, you put it back into the file cabinet. The changes you practice to data plot of ground working on it replace the passe-partout data in the file cabinet (unless you store it in a different place). Novice computer users often confuse storage with memory.Although the func tions of storage and memory arc similar they work in different delegacys. There arc three major distinctions between storage and memory There is more than inhabit in sto rage than in memory, just as there is more room in a file cabinet tlian there is on a tabletop. Contents are retained in storage when the computer is turned off, whereas programs or the data in memory disappear when you shut down the computer. Storage devices operate much slower than memory chips, bur storage is much cheaper than 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. Both are covered in the undermentioned sections.Magnetic Storage There are many types of computer storage, but the about common is the magnetic disk. A disk is a round, flat object that spins around its center. (Magnetic disks are almost al elans house inside a case of some kind, so you disregardt give away the disk itself unless you pass the case. ) Read/write heads, which work in much the same way as the heads of a tape recorder or VCR, are used to read data from the disk or write data onto t he disk. The device that holds a disk is wished a disk gravel. Some disks are built into die drive and are not meant to be shiftd other kinds of drives enable you to remove and replace disks (see respect IB. 12).Most personal computers have at least(prenominal) one nonremovable hard disk (or hard drive). In addition, there is also a diskette drive, which allows you to use removable diskettes (or floppy disks). The hard disk serves as the computers primary filing cabinet because it stick out store removed more data than a diskette can contain. Diskettes are used to load data onto the hard disk, to trade data with other users, and to make patronage copies of the data on the hard disk. Introducing Computer Systems sch cypher 1B. 12 Standard PCs haw a buB-in hart disk and a octette dim The hard dfck is bult into the computers case. Diskettes can be inserted into and removed from the diskette drive. Optical StorageIn addition to magnetic storage, closely every computer sold t oday let ins at least one form of optical storagedevices that use lasers to read data from or w rite data to the reflective surface of an optical disc. The compact disc recordableOM drive is the most common type of optical storage device. Com pact discs (CD s) arc a type of optical storage, identical to audio CDs. U ntil re cently, a stock CD could store about 74 minutes of audio or 650 M B of data. A newer breed of CDs can hold 80 minutes of audio or 700 M B of data (see Fig ure 1B. 13). The type used in computers is called Compact Disc Read-Only Mem ory (CD -RO M ). As the trace implies, you cannot change the inform ation on the disc, just as you cannot record over an audio CD.If you purchase a CD-Recordable (CD-R) drive, you have the option of creat* ing your own CDs. A CD-R drive can 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 can be written on only once, or a CD-ReW ritable (CD-RW ) disc, which can be written to m ultiple times, the give care a floppy disk. An increasingly popular data storage technology is the Digital Video Disc (D V D ), which is revolutionizing home entertainment. Using sophisticated com ex compaction technologies, a private DVD (which is the same size as a measure compact disc) can store an entire full-length movie. DVDs can hold a minimum of 4. 7 G B of data and as much as 17 G B.Future D VD technologies announce much higher stor age capacities on a single disc. DVD drives also can locate data on the disc much double-quick than banal CD-ROM drives. DVDs require a special player (see Figure IB . 14). M any DVD players, how ever, can play audio, data, and DVD discs, freeing the user from purchasing dif ferent players for separately type of disc. D VD drives are now standard equipment on many new personal computers. Users not only can install programs and data from their standard CDs, but they also can watch movies on their personal computers by utilize a DVD. FIGURE 1B. 13 Software nakers commonly sel Oier productson CDbecauseof the dscs high storage capaoty. Software Brings the Machine to LifeThe ingredient that enables a computer to perform a specific assess is software, which consists of book 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 program, it is said to be run ning or executing that program. Although the array of available programs is vast and varied, most software falls into two major categories system software and industry software. ONLINE FormoreInformation on computersoftware, visit http//www. mhhe. com/ petemorton 32 Chapter 1 System SoftwareSystem software is any program (hat get words the computers hard ware or that can be used to maintain the computer in some w ay so th at 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 operating systems let in Windows, the Macintosh in operation(p) System, and Linux (see Figure IB . 15). An operating system is essential for any computet because it acts as an reckoner between 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 (such as copying or printing a file), your request is handled by the operating system. A network operating system allows omputers to communicate and share data across a network while controlling network op* erations and overseeing the networks security. A u tility is a program that makes the computer system easier to use or performs highly specialized functions (see Figure IB . 16). U tilities arc used to manage disks, troubleshoot hard* war e problems, and perform other tasks that the operating sys tem itself may not be able to do. FIG U RE 1B. 14 DVDplayersare now standardon many PCsand are foundin marryhome entertainmentcentos. Application Software Application software tells the computer how to accomplish specific tasks, such as word processing or drawing, for the user.Thousands of applications are available for many uses and for large number o f all ages. Some of the major categories of these applications include Word processing software for creating text-based documents such as newsletters or brochures (see Figure IB . 17). Spreadsheets for creating numeric-based documents such as budgets or bal ance sheets. FIG U RE 1B. 15 Windowsis Ihe mostpopular cf aS PC operatingsystems, runningonabout BagiEBEBBjBSi 90 percentof al personalcomputers. Introducing Computer Systems 33 Urheberrechtlich geschutzles M Database management software for construction and manipulating oversized sets of data, such as the names, ad dresses, and phone flakes in a telephone pointory.Presentation programs for creating and presenting electronic slide shows (see Figure 1B. 18). Graphics programs for designing illus trations or manipulating photographs, movies, or animation. Multim edia authoring applications for building digital movies that incorporate sound, video, anim ation, and active features. Entertainment and education software, many of which are interactive multime dia events. FIGURE 1B. 16 Web design diaphysiss 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 can be played by several people over a network or the Internet.Thereare hundreds of utility programs available forpersonal computers. This one. caled ParttlonMagic, helps you manage jour hard cfisKto getthe most from it Computer Data You have 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 exponent think of the letters of the alphabet as data. Taken individually, they do not mean a lot. But when grouped into words and sentences, they make sense that is, they break down information (see Figure IB . 19). Sim ilarly, basic geometric shapes may not have much meaning by themselves, but when they arc grouped into a invention or a chart, they change by reversal 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 designed (or creating documentsthatconsistprimarily of text, but also lets youadd graphcs and sounds to your documents. It also provides layout features that letyou create 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 T W 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 1002 AIMMBSB8ZT sunu,iL4nw C i A Urheborrechtlich geschOtztes M FIGURE 1B. 18 T oil rtyt Sj fca f Presentation software is mostoften used torcreating sales presentations,aXtvxjgh I can 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 hook Variants of the Mouse Ergonomics and Input Devices Lesson 2B Inputting D ata In O ther W ays Devices for the glide by Optical Input Devices Audiovisual Input Devices LESSON v m Overview T he K eyboard an d M ouseIf you think of the processor as a computers brain, because you might think of the input devices as its sensory organsthe eyes, ears, and fingers. From the users point of view, input devices are just as consequential as the CPU, perhaps even more important. After you buy and set up the com* put cr, you may take the CPU for granted because you interact directly with input devices and only indirectly with the CPU. But your ability to use input devices is critical to your overall success with the whole system. An input device docs on the dot what its name suggests it enables you to enter information and commands into the computer. The most com* monly used input devices arc the chance uponboard and the fawn.If you buy a new personal computer today, it w ill include a delineateboard and abstract un less you specify otherwise. Other types of input devices arc available as well, such as variations of the crawl and specialized utility(a) input devices such as microphones and scanners. This lesson introduces you to the divulgeboard and the shiner. You w ill learn the importance 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 Identity the five key groups on a standard computer keyboard. Name six special*purpose keys found on all standard computer keyboards. List the steps a computer follows when accepting input from a keyboard. Describe the purpose of a common mackerel and the rote it plays in computing. sign of the zodiacize the five essential techniques for using a mouse. Identify three common variants of the mouse. Describe five steps you can take to avoid clamant assay 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 first peripherals to be used with computers, and it is still the primary input device for entering text and numbers. A standard keyboard includes about 100 keys each key sends a different signal to the CPU.If you have not used a computer keyboard or a typewriter, you w ill learn quickly that you can use a computer much more effectively if you know how to type. The skill of typing, or keyboarding, is the ability to enter text and numbers with skill and accuracy. Certainly, you can use a computer without having good typing skills. Some people claim that when computers can interpret handwriting and speech with 100 percent accuracy, typing w ill be rise unnecessary. But for now and the stalkseeable 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 various models differ in size, shape, and smack except for a few special-purpose keys, most keyboards arc laid out almost identi cally. Among IBM-compatible computers, the most common keyboard layout is the IBM Enhanced Keyboard. It has about 100 keys arranged in five groups, as shown in Figure 2A. 1. (The term IBM-compatible computer refers to any PC based on t he first personal computers, which were made by IBM . Today, an IBMcompatible PC is any PC other than a Macintosh computer. ) The Alphanumeric Keys The alphanumeric keys(he area of the keyboard that looks like 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. Along 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 resort hotel c e , and e n t e r keys are described in Figure 2A. 2. FIGURE 2A . 1 Most BM com pattie PCs use a keyboard like M s one. Mar/ keyboards feature a number of specialized keys, am)keyboardscan vary in size and shape. But nearly e l standard PC keyboards include the keys shewn here. The Modifier Keys The SHIFT, ALT (Alternate), and CTRL (Control) keys are called modifier keys be cause they modify the input of other keys.In other words, if you hold down a modifier key while press 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). Theback station keyerases point of references youhavejusttyped. Forexam ina ple, word processingprogramyoucan press baosmce to backover an Incorrect character anddelete it Thecaps lock keylets youlock* the alphabetkeys sotheyproduceonly seat of government letters. The ehter key letsyou finalize dataentry inm typesof appBcatkmprogram any s. Ybualso can usewtw tocboosecom ands m andoptionsin m program and at any s various places in anoperatingsystems Interface. FIGURE 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 insistency the J key, you input a capital /. M odifier keys arc extremely useful bccausc they give all othe r keys multiple 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 Whenpressedalong with analphanumerickey,smft forcesthe /).The numeric keypad also features 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, alongwtthcursor-m ovem keys toselect textforediting. ent the numeric keypads keys perform cursor case 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 along the top of the key board. They allow you to input c ommands without typing long strings of characters or navigating menus or dialog 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 results dependingonthe programyouare using. In m Windows-based program any s, cm-key combinationsprovideshortcuts for m com ands. Forexam the enu m ple, combinationcnuo enables youto open a newfile. n Them j (mjcmmu) keyoperates Skethectrl key,but producesa different set of results. In Windowsprogram Mi-key s. combinations enableyouto navigate m enus anddialog boxeswithoutusingthe m ouse. FIGURE 2A . 3 Fuvtionsoftheshft, emuanda lt keys. Interacting with Your Computer 51 the program you are using. Most IBM-compatible keyboards have 12 function keys. Many programs use function keys along with modifier keys to give the func tion keys more capabilities. The Cursor-Movemen t KeysMost standard keyboards also include a set of cursor-movcmcnt keys, which let you move around the screen without using a mouse. In many programs and op* erating systems, a mark on the screen indicates where the characters you type w ill be entered. This mark, called the cursor or interpolation point, appears on the screen as a blinking 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 addition to the five groups of keys described earlier, all IBM*compatible key boards feature six special-purpose keys, each of which performs a unique func tion. Figure 2A. describes these spccial-purposc keys. Since 1996, nearly all IBM-compatible keyboards have include two additional special-purpose keys designed to work with the Windows operating systems (see Figure 2A. 7) stir up . This key, which features t he Windows logo (and is sometimes called the Windows logo key), opens the Windows Start menu on most computers. Pressing this key is the same as clicking the Start clit on the Windows taskbar. 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. iodine of the latest trends in keyboard technology is the addition of Internet and multimedia controls.Microsofts Internet Keyboard and MultiMedia Keyboard, for example, feature outlets that you can program to perform any number of tasks. For example, you can use the buttons to launch a Web browser, check 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 prior screen press m gedonn to jump to the next ___ I The arrow keys move the insertion point up or down a single line, or leftfield or right one character space. FIGURE 2A . 4 The airsor-movement keys. FIGURE 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. lockcauses the e cursorto remainstationary 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 envelop m ode (in wtiich textis inserted into thedocum at the cursor) toovertypem ent ode (in whichnewtextis typodover existingte xt), andvice vena. m N A 4 f I 6 m n ? 6 a ? 3 i* J removesonecharacterat a time at thecursors localization of function, cam erases characterstothe right otthecursor. FIGURE 2A . 6 SpecU jwpose keysonm standard ost keyboards FIGURE 2A . 7 ThosafiT keyandtheatofiran toy appear frequencyontherwwer keytnordsthat are sdldwAhWndcMiS basedcom puters. 2Z and start your most frequently used programs. Multimedia buttons let you control the computers CD-ROM or DVD drive and adjust the speaker volume. Many 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 simply sends the letter of a pressed key to the computerafter 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 controller notes that a key has been presxd. The keyboard controller places a code in to pan of its memory. Interacting with Your Computer 53 B i f a S Q ill FIGURE 2A. 8 called the keyboard buffer, to indicate which key was pressed. (A buffer is a tem porary storage area that holds data until it can be processed. ) The keyboard con commonplace 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 system reads the Q Thesystemsoftwareresponds to memory location in the keyboard He Interruptby reading 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 BUFFER SOFTWARE code to the CPU. 0 The keyboard controler e The keyboardcontroller The keyboard buffer can store Q The system software sends an interrupt sendsDiescan code passes the sca n code many keystrokes at one time.This request to the forthe key tothe tothe CPU capability is necessary because keyboardbuffet system software. some time elapses between the pressing 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 quickly. Unless the computer is very busy intervention multiple tasks, you notice no delay between pressing keys and seeing the letters on your screen. In some computers, the keyboard controller handles input from the computers keyboard and mouse and stores the grounds 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. (Y ou 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 commonly include a mouse as the pointing dcvicc.A mouse 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 pointer (also called the mouse pointer) 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 pointer in a program window. FIGURE 2A. 10 Most modern personal computers are eqlipped w ti a mctse. 54 Chapter 2 The machinelike mouse is the most common type of pointing de vice. A mechanical mouse conta ins a small rubber ball that shank 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, accusation, 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 underside 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 button the cursor appears at that location.Second, instead of forcing you to type or disobl ige commands from the key board, the mouse and mouse-based operating systems let you choose 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 remembering obscure command names, users can figure out quite an easily 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 Thepartsofa 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 spinning 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 an optical mouse. If you use a drawing program, you can use the mouse to crcatc prowess such as lines, curves, and freehand shapes on the scrccn. The mouse has helped establish 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 accomplished by com bining point ing w ith these techniques snaping Double-clicking pull 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 across your desk. O n the scrccn, the pointer moves in relation t o 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 dogging arc usually carried out w ith the left mouse button (see Figure 2A. 17). In m ulti button mice, one button must be designated FIGURE 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 ope rating system, application software, and mouse-control software. To click an item w ith the mouse, you move the pointer to the item on the scrccn. When the pointer touches the object, quickly press and release 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 item means pointing to the item with the mouse pointer and then pressing and releasing the mouse button twice in rapid succession (see Figure 2A. 19). Double-clicking is prim arily used with desktop objects such as icons. For example, you can double-click a pro click click grams icon to launch the program. Dragging an item means positioning 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 dragged along with it across the scrccn (see Fig ure 2A. 20). You can then nightfall 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 practised 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 support 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 pertain to the item to which you arc pointing.A roulette 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 th rough long docu ments. N ot all applications and operating systems support the use o f the wheel. FIGURE 2A. 17 Standardbutton configuration 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 add Configurations m IN E For m tatorm ore atJononthecare andusageofrrtce. visit http//www. mhhe. com/ pctemorton FIGURE 2A. 22 Avrfieel mouse.The mouse usually 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 configuration 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(prenominal) 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 ready to hand(predicate) tool, some people do MMbi not like using a mouse or have difficulty maneuvering 1(0* one. For others, a mouse W D i W tfW w requires too much desktop jo* spacea real problem when you are not working at a deskl Uw aJi tM For these reasons and others, hardware makers have developed 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 taking up les s space than a mouse.They all remain sta tionary and can even be built into the keyboard. Trackballs A trackball is a pointing device that works like an upside-down mouse. You anticipate 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 computer computers, which typically are used on laps or on small 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 Circle 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 suitable for a notebook computer. Some notebook models feature a built-in trackpad rather than a mouse or trackball (sec Figure 2A. 25). Like mice, trackpads usually are separate from t he keyboard in desktop com puters and are attached 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 Pointers in the Keyboard Many portable computers now fea ture a small joystick positioned near the middle 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 hands off the keyboard to use this device, they can save a great deal of time and effort. Tw o buttons that per form the same function as mouse buttons are just beneath the space bar and are pressed with the thumb. Several generic terms 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 Saving 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-increasing 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 invaluable tool. Programmers began devising keyboard shortcuts that allow users to contract commands quickly by typing a short combination of keystrokes. Keyboard shortcuts involve using a modifier key (such as aut or cm. ) alo ng 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 universal way to access online help. IBMcompatible computer keyboards originally had 10 function keys eventually the number of function keys was expanded 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 menu 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 Common User Access (CUA) standard led to the standardization of many commonly used hotkeys across dif ferent programs and environments. With this standard for commonly used hotkeys, users have fewer 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 screen 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 worker 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 chair too long, but hand and radio carpal joint injuries can result from using a keyboard and mouse for long periods. Eyes can become strained from staring at a monitor for hours. Such injuries can be extreme, threatening the users general health and ability to work. Much is being done to make computers easier safer, and more comfortable to use.Ergonomics, which is the field of view of the physical relationship between people and their toolssuch as computers addresses these issues. Now more than ever before, people recognize the impor tance of having ergonomically correct computer furniture and using proper posture and techniques while working with computers. (The term ergonomically correct means that a tool or a workplace is designed to work decently with the human 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 bluff character formatting 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 show character formatting on or off for the selected or inserted text underline letters Oecrease boldness size for the selected or inserted text Increase font size for the selected or inserted text Remove paragraph formatting for the selected paragraph or paragraphs Remove character formatting for the selected text Copy the selected text or object Cut the selected text or object Paste 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 shortcu ts 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 crying Stress Injuries The field of ergonomics did not rcccivc much attention 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 stress 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 ca rpal 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 office worftcan pose speofc healti risks. Interacting with Your Computer 61 Urheberrechtlich geschulzles M Transverse Cross Section of NormalW rit FlexorTendons and Sheath . . exacerbate Inflamedtendon sheath presses against median nerve carpal?. * Bones FIGURE 2A . 2 8 Carpel tunnel syndrom affectsthe e nervesrunningthroughthe carpal tunnel of thewrist. The carpal tunnel is a passageway 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 slapdash 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 ina bility to use the hands. Carpal tunnel syndrome is the best-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. Avoiding Keyboard-Related Injuries If you use a computer frequently, you can avoid RSIs by adopting a few good work habits, and by making sure that your hardware and workspace are set up in an ergonomically friendly way. At Jssue Com puter Voting Is It a Good Thing?The dispute over electronic voting is as heated as a postulate 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 elector preferences and report themreliably and accu rately. Some assert that electronic systems are safer than other methods of voting because they give security checks and audit trails, and are tougher to tamper with than paper ballots. One of the most widely used electronic voting systems. Diebold election 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 cigarette areas on an electronically gener ated ballot pad. Each unit provides a direct-entry computerized voting station that automatically records and stores ballot infor mation and results. While 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 Central for accurate and timely jurisdictionwide results. However, electronic voting systems have generated con cer n because their work is not readily accessible for inspec tion what goes on behind the screen is a mystery to the general public and therefore causes uneasiness. With com puter voting, voter records are intangibly stored on a hard drive, with voting results recorded in electronic memory. Indeed, a July 2003 compendium 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 possibility of fraud, electronic 62 Chapter 2 Urheberrechllich oesch When setting up your computing workspace, make it a prior ity to choose a comfortable, ergonomically designed chair (sec Figure 2A. 29). Your office chair should Allow you to adjust its height. go out good 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 hands 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 straight, rather than angled outward) while typing (see Figure 2A. 31). Use a Padded wrist joint Support. If you type a lot, a wrist support can be helpful by allowing you to rest your hands comfortably when you are not rattling typ ing. Remember 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 redundant security checks and audits and m ay 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 verify 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 recent 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 woful over the keyboard. sustentation 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 fatigue. Sit Up Straight. Avoid slouching as you type, and keep your feet flat on the floor in front of you. Avoid crisscross 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 hunt 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 minu tes 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 Review 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 alphanumeric 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 Generically, 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-clickin g, 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- arcticing, 57 trackpad, 59 TrackPoint 60 wheel mouse, 57 Interacting with Your Computer 65 Urheberrechtlich g esch u tztes M tLgg 8 0 K ey Term try 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 fo ur 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. Multiple 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 th e 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 Urheberrechtlich 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 keyboa rds 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 syndrome. 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 classmate 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 Pointer 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 ordinary input device may nor be the best choice. In a dusty factory or wa rehouse, for example, a standard keyboard or mouse can be dam* aged if it becomes clog with dirt. Grocery 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 scrccn 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 games 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