Looking atComputers:

Understanding the Parts

From Chapter 2 of Technology in Action, Complete, Fifth Edition, Alan Evans, Kendall Martin, Mary Anne Poatsy. Copyright © 2009 by PearsonEducation. Published by Prentice Hall. All rights reserved.

Looking atComputers:

Understanding the Parts

ObjectivesAfter reading this chapter,

you should be able toanswer the following

questions:

1. What exactly is a computer, and what are its four main functions?

2. What is the difference between data and information?

3. What are bits and bytes, and how are they measured?

4. What devices do you use to get data into the computer?

5. What devices do you use to get information out of the computer?

6. What’s on the front of your system unit?

7. What’s on the back of your system unit?

8. What’s inside your system unit?

9. How do you set up your computer to avoid strain and injury?

• Understanding Bits and Bytes• Using Input Devices • Using Output Devices

ACTIVE HELPDESK

Setting Up Your SystemJillian has just bought a new computer and is setting it up. She spent more thanshe had planned on a flat-panel monitor, which she places on her small desk. Ittakes up far less room than her old monitor, which was big and bulky. Next shepulls out her system unit, which she knows is the component to which she’llconnect all the other pieces of her system. Although she was tempted to buy themost powerful computer on the market, she bought one that best met her needsand was slightly less expensive. Still, it came with a CD-RW/DVD comboplayer, a 100-GB hard drive, and what the computer salesperson said wasenough memory and power to do almost anything. She sets it on the floor nextto her desk and attaches the monitor to it.

Next she pulls out her keyboard. She looked into buying a wireless key-board, but because her budget was tight, she bought a standard keyboardinstead. The box tells her it is a “USB” keyboard, so she finds what looks tobe the right port on the back of her system unit and plugs it in. Her mousealso needs a USB port. Finding another USB port, she attaches themouse there. She’s glad that her system has plenty of USB ports andsees there are even several on the front of the system unit. She sets upher speakers next. Although the salesperson told her she’d probablywant to upgrade them, she decided to wait until she could afford it.She arranges them on her desk and inserts the speakers into the“speaker out” port on the back of her tower. Last is her printer. Shedebated over which type of printer to buy but decided to buy aninkjet because she prints a lot of color copies and photos. She findsthe right port on her system unit and connects it. She then plugs thepower cables of the monitor, speakers, printer, and system unit intothe surge protector, which the salesperson told her would protecther devices from power surges. All that’s left is to make sure hersetup is comfortable, and she’s ready to go.

What kind of computer setup do you have? Do you know all theoptions available and what the different components of your systemdo? In this chapter, we’ll take a look at your computer’s basic parts.You’ll learn about input devices (such as the mouse and keyboard), out-put devices (such as monitors and printers), storage devices (such as thehard drive), as well as components inside the computer that help it to function.Finally, you’ll learn how to set up your computer so that it’s safe from powersurges and comfortable to work on.

SOUND BYTES• Port Tour: How Do I Hook It Up? • Virtual Computer Tour • Healthy Computing

B2M Productions/Getty Images-Digital Vision

Looking at Computers: Understanding the Parts

pieces of data. But how useful are thesechunks of data to you? Information is datathat has been organized or presented in ameaningful fashion. When your computerprovides you with a contact listing that indi-cates Derek Washington can be reached byphone at (612) 555-3297, the data mentionedearlier suddenly becomes useful—that is, itis information.

How do computers interact withdata and information? Computers arevery good at processing (manipulating) datainto information. When you first arrived oncampus, you probably were directed to aplace where you could get an ID card. Youmost likely provided a clerk with personaldata (such as your name and address) thatwas entered into a computer. The clerk thentook your picture with a digital camera (col-lecting more data). This information wasthen processed appropriately so that it couldbe printed on your ID card (see Figure 1).This organized output of data on your IDcard is useful information. Finally, the infor-mation was probably stored as digital dataon the computer for later use.

BITS AND BYTES: THELANGUAGE OF COMPUTERS

How do computers process data intoinformation? Unlike humans, computerswork exclusively with numbers (not words).In order to process data into information,computers need to work in a language theyunderstand. This language, called binarylanguage, consists of just two digits: 0 and 1.Everything a computer does (such asprocess data or print a report) is brokendown into a series of 0s and 1s. Each 0 and 1is a binary digit, or bit for short. Eight

Output InformationInput DataProcessing (Organizing)

Information into DataUsing a Database

FIGURE 1

Computers processdata into information.

Understanding YourComputerYou can see why becoming computer literateis so important. But where do you start?You’ve no doubt gleaned some knowledgeabout computers just from being a memberof our society. However, although you cer-tainly know what a computer is, do youreally understand how it works, what all itsparts are, and what these parts do? In thissection, we’ll discuss what a computer doesthat makes it such a useful machine.

COMPUTERS ARE DATAPROCESSING DEVICES

Strictly defined, a computer is a data pro-cessing device that performs four majorfunctions:

1. It gathers data (or allows users to inputdata).

2. It processes that data into information.

3. It outputs data or information.

4. It stores data and information.

What is the difference betweendata and information? People often usethe terms data and information interchange-ably. Although in a simple conversation theymay mean the same thing, when discussingcomputers, the distinction between data andinformation is an important one.

In computer terms, data is a representa-tion of a fact or idea. Data can be a number,a word, a picture, or even a recording ofsound. For example, the number 6125553297and the names Derek and Washington are

©Chuck Savage/CORBIS All Rights Reserved

Understanding Your Computer

binary digits (or bits) combine to create onebyte. In computers, each letter of the alpha-bet, each number, and each special character(such as the @ sign) consists of a uniquecombination of eight bits, or a string of eight0s and 1s. So, for example, in binary (com-puter) language, the letter K is representedas 01001011. This equals eight bits, or onebyte.

What else can bits and bytes beused for? You’ve probably heard the termskilobyte (KB) and megabyte (MB) before. Notonly are bits and bytes used as the languagethat tells the computer what to do, they arealso what the computer uses to represent thedata and information it inputs and outputs.Word-processing files, digital pictures, andeven software programs are all representedinside a computer as a series of bits andbytes. These files and applications can bequite large, containing many millions ofbytes. To make it easier to measure the size ofthese files, we need larger units of measurethan a byte. Kilobytes, megabytes, and giga-bytes are therefore simply amounts of bytes.As shown in Figure 2, a kilobyte (KB) isapproximately 1,000 bytes, a megabyte (MB)is about a million bytes, and a gigabyte (GB)is about a billion bytes. As our informationprocessing needs have grown, so too haveour storage needs. Today, some computerscan store up to a petabyte of data—that’smore than one quadrillion bytes!

How does your computer processbits and bytes? Your computer uses acombination of hardware and software toprocess data into information and enable youto complete tasks (such as writing a letter orplaying a game). An anonymous person oncesaid that hardware is any part of a computerthat you can kick when it doesn’t work prop-erly. A more formal definition of hardware isany part of the computer you can physicallytouch. However, a computer needs more thanjust hardware to work: it also needs someform of software. Think of a book withoutwords or a CD without music. Without wordsor music, these two common items are justshells that hold nothing. Similarly, a computerwithout software is a shell full of hardwarecomponents that can’t do anything. Softwareis the set of computer programs that enablesthe hardware to perform different tasks. Thereare two broad categories of software: applica-tion software and system software.

When you think of software, you aremost likely thinking of application software.Application software is the set of programsyou use on a computer to help you carry outtasks. If you’ve ever typed a document, cre-ated a spreadsheet, or edited a digital photo,for example, you’ve used a form of applica-tion software.

System software is the set of programs thatenables your computer’s hardware devicesand application software to work together.The most common type of system software is

ACTIVEHELPDESK

Understanding Bitsand Bytes

In this Active Helpdesk call,you’ll play the role of ahelpdesk staffer, fielding callsabout the difference betweendata and information andwhat bits and bytes are andhow they are measured.

FIGURE 2 How Much Is a Byte?

Name Abbreviation Number of Bytes Relative Size

Byte B 1 byte Can hold one character of data.

Kilobyte KB 1,024 bytes Can hold 1,024 characters or about half of a double-spaced typewritten page.

Megabyte MB 1,048,576 bytes A floppy disk holds approximately 1.4 MB of data, orapproximately 768 pages of typed text.

Gigabyte GB 1,073,741,824 bytes Approximately 786,432 pages of text. Since 500 sheetsof paper is approximately 2 inches, this represents a stackof paper 262 feet high.

Terabyte TB 1,099,511,627,776 bytes This represents a stack of typewritten pages almost 51miles high.

Petabyte PB 1,125,899,906,842,624 bytes The stack of pages is now 52,000 miles high, or aboutone-fourth the distance from the earth to the moon.

Looking at Computers: Understanding the Parts

the operating system (OS), the program thatcontrols the way in which your computer sys-tem functions. It manages the hardware of thecomputer system, such as the monitor and theprinter. The operating system also provides ameans by which users can interact with thecomputer. For the rest of this chapter, we’llexplore hardware.

Your Computer’sHardwareConsidering the amount of amazing thingscomputers can do, they are really quite sim-ple machines. A basic computer system ismade up of software and hardware. In thischapter, we look more closely at your com-puter’s hardware, the parts you can actuallytouch (see Figure 3). Hardware componentsof a computer consist of the system unit, thebox that contains the central electronic com-

ponents of the computer, and peripheraldevices, those devices such as monitors andprinters that are connected to the computer.Other devices, such as routers, help a com-puter communicate with other computers tofacilitate sharing documents and otherresources. Together the system unit andperipheral devices perform four main func-tions: they enable the computer to input data,process that data, and output and store the dataand information. We begin our exploration ofhardware by taking a look at your com-puter’s input devices.

Input DevicesAn input device enables you to enter data(text, images, and sounds) and instructions(user responses and commands) into thecomputer. The most common input devicesare the keyboard and the mouse. You usekeyboards to enter typed data and com-mands, whereas you use the mouse to enter

Input Storage

Processing Output

FIGURE 3

Each part of the com-puter serves a specialfunction.

Input Devices

a

b

c

user responses and com-mands. There are other inputdevices as well: microphonesinput sounds, whereas scan-ners and digital camerasinput nondigital text and digi-tal images, respectively.Styluses (devices that look likeskinny pens but have no ink)and electronic pens are alsobecoming quite popular and areoften used in conjunction withgraphics tablets that can translate auser’s handwriting into digital input.

KEYBOARDS

Aren’t all keyboards the same? Mostdesktop and notebook computers come witha standard keyboard, which uses theQWERTY keyboard layout (see Figure 4a).This layout gets its name from the first sixletters in the top-left row of alphabetic keyson the keyboard. Over the years, there hasbeen some debate over what is the best lay-out for keyboards. The QWERTY layout wasoriginally designed for typewriters and wasmeant to slow typists to prevent typewriterkeys from jamming. Today, the QWERTYlayout is considered inefficient because itslows typing speeds. Now that technologycan keep up with faster typing, other key-board layouts are being considered.

The Dvorak keyboard is the leading alter-native keyboard, although it is not nearly ascommon as the QWERTY. The Dvorak key-board puts the most commonly used letters inthe English language on “home keys,” the keysin the middle row of the keyboard (see Figure4b). The Dvorak keyboard’s design reduces thedistance your fingers travel for most key-strokes, increasing typing speed. Althoughalternative layout keyboards have not caughton with most users, they are very popular withgamers. Keyboards such as the DX1 fromErgodex (see Figure 4c) allow placement of thekeys in any position on the keyboard tray, andthe keys can be programmed to perform spe-cific tasks. This makes it easy for gamers toconfigure a keyboard in the most desirableway for each game they play.

Because users are demanding more porta-bility out of their computing devices, recentdevelopment efforts have focused on reduc-ing the size and weight of keyboards. Thevirtual laser keyboard (see Figure 5) is a

FIGURE 5

Light and portable, thevirtual laser keyboardis a small device thatprojects the image of aQWERTY keyboard onany surface. Sensorsdetect the typingmotions of a user’s fin-gers, and data is trans-mitted to a computingdevice via Bluetoothtechnology.

FIGURE 4

(a) The first six keys inthe top-left row ofalphabetic keys givethe QWERTY keyboardits name. QWERTY isthe standard keyboardthat comes with mostcomputers. (b) With aDvorak keyboard, youcan type most of themore commonly usedwords in the Englishlanguage with the let-ters found on “homekeys,” the keys in themiddle row of the key-board. (c) The ErgodexDX1 allows keys to beplaced anywhere onthe pad, and they canbe programmed toindividual keystrokesor with macros (aseries of tasks). Thekeys can be relocatedand reprogrammedeasily, making it popu-lar with gamers.Presently, there arethree main applica-tions for the Ergodextechnology embodiedin the DX1: entertain-ment (e.g., gaming,flight simulation), pro-fessional productivity(e.g., Photoshop,Autocad, etc.) andAssistive Technology(victims of arthritis,cerebral palsy, etc.).

Ergodex

Martin Meissner/AP Wide World Photos

Looking at Computers: Understanding the Parts

Function keys

Cursor control keysAlt keyWindows key Windows keyControl (Ctrl) key

Multimedia controls

Numerickeypad

Toggle and other keys

Internet controls

device that is about the size of a cellularphone. It projects the image of a keyboard onany surface, and sensors detect the motion ofyour fingers as you “type” on a desk. Data istransmitted via Bluetooth technology.Bluetooth is a wireless transmission standardthat facilitates the connection among elec-tronic computing devices such as cell phones,PDAs, and computers to peripheral devicessuch as keyboards and headsets.

How can I use my keyboard mostefficiently? All keyboards have the stan-dard set of alpha and numeric keys that youregularly use when typing. As shown inFigure 6, other keys on a keyboard also havespecial functions. Knowing how to use thesespecial keys will help you improve your effi-ciency:

• The numeric keypad allows you toenter numbers quickly.

• Function keys act as shortcut keys youpress to perform special tasks. They aresometimes referred to as the “F” keysbecause they start with the letter Ffollowed by a number. Each softwareapplication has its own set of tasksassigned to the function keys, althoughsome are more universal. For example,the F1 key is usually the Help key in soft-ware applications. However, functionkeys sometimes perform different actions

in different software packages. Forinstance, the F2 key moves text or graph-ics in Microsoft Word but allows editingof the active cell in Microsoft Excel.

• The Control (Ctrl) key is used in combi-nation with other keys to perform short-cuts and special tasks. For example,holding down the Control (Ctrl) keywhile pressing the B key adds bold for-matting to selected text. Similarly, youuse the Alt key with other keys for addi-tional shortcuts and special tasks. (OnMacs, the Control or Ctrl key is theApple key or Command key, whereasthe Alt key is the Option key.)

• The Windows key is specific to theWindows operating system. Used alone,it brings up the Start menu; however, it’sused most often in combination withother keys as shortcuts (which producedifferent results in different versions ofWindows). For example, pressing theWindows key plus the M key minimizesall Windows in Windows Vista.

Some keyboards (such as the one shown inFigure 6) also include multimedia and Internetkeys or buttons that enable you to open a Webbrowser, view e-mail, access Help features, orcontrol your CD/DVD player. Unlike the otherkeys on a standard keyboard, these buttons arenot always in the same position on every

FIGURE 6

Desktop keyboardshave a variety of keysthat help you workmore efficiently.

Input Devices

B I T S A N D B Y T E SKeeping Your Keyboard Clean

To keep your computer running at its best, it’s important that youoccasionally clean your keyboard.

To do so, follow these steps:

1. Turn off your computer. Disconnect the keyboard from yoursystem.

2. Turn the keyboard upside down and gently shake out anyloose debris. You may want to spray hard-to-reach places withcompressed air (sold in cans and found in most computerstores) or use a vacuum device made especially for computers.Don’t use your home vacuum because the suction is too strongand may damage your keyboard.

3. Wipe the keys with a cloth or cotton swab lightly dampenedwith a diluted solution of dishwashing liquid and water orrubbing alcohol and water. Don’t spray or pour cleaning solu-tion directly onto the keyboard. Make sure you hold the key-board upside down or at an angle to prevent drips from run-ning into the circuitry.

keyboard, but the symbols on top of the but-tons generally help you determine their func-tion. For hard-core gamers, gaming companiesare now selling gaming keyboards that areoptimized for playing specific video games.These keyboards contain special keys that per-form special functions (such as changing theweapon being used by a character) so that withone key press, game play speeds up, allowingplayers to react quicker to difficult challengeswithin the game.

Another set of controls on standard key-boards are the cursor control keys thatmove your cursor (the flashing I symbol onthe monitor that indicates where the nextcharacter will be inserted). The cursor con-trol keys also are known as arrow keysbecause they are represented by arrows onstandard keyboards. The arrow keys movethe cursor one space at a time in a docu-ment, either up, down, left, or right.

Above the arrow keys, usually you’ll findkeys that move the cursor up or down onefull page or to the beginning (Home) or end(End) of a line of text. The Delete (Del) keyallows you to delete characters, whereas theInsert key allows you to insert or overwritecharacters within a document. The Insertkey is a toggle key because its functionchanges each time you press it: when tog-gled on, the Insert key inserts new textwithin a line of existing text. When toggledoff, the Insert key replaces (or overwrites)existing characters with new characters asyou type. Other toggle keys include theNum Lock key and the Caps Lock key,which toggle between an on/off state.

Are keyboards different on note-books (laptops)? Notebook computersare portable computers that are powered bybatteries and have keyboards, monitors, andother devices integrated into a single compactcase. To save space and weight, notebook key-boards are more compact than standard key-boards and therefore have fewer keys. Still, alot of the notebook keys have alternate func-tions so that you can get the same capabilitiesfrom the limited keys as you do from the spe-cial keys on standard keyboards. For example,many notebook keyboards do not have sepa-rate numeric keys. Instead, the letter keysfunction as number keys when they arepressed in combination with another key(every notebook will be different). The keysyou use as numeric keys on notebooks havenumber notations on them so you can tellwhich keys to use (see Figure 7).

Keys function asnumber keys when

pressed withanother key

FIGURE 7

Notebook keyboards are more compact than traditional desktop keyboards andusually don’t include extra keys such as the numeric keypad. However, on manynotebooks, certain letter keys can function as number keys.

Hewlett-Packard Company

Looking at Computers: Understanding the Parts

What about keyboards for PDAsand Tablet PCs? Generally, you

enter data andcommands intoa personal digi-

tal assistant (PDA) by usinga stylus, a pen-shapeddevice that you use bytapping or writing on the

PDA’s touch-sensitivescreen. Tablet PCs,as shown in Figure8, are similar to

notebook PCs but alsofeature a touch-sensitive

screen and handwriting recogni-tion software. Tablet PCs also allow

user input via a stylus. However, all tabletsand some PDAs have built-in keyboards thatallow you to type text just as you would witha normal keyboard. If your PDA doesn’tinclude a built-in keyboard, you can buykeyboards that attach to the PDA or use avirtual laser keyboard.

Are all conventional keyboardsconnected to the computer viawires? Although most desktop PCs shipwith wired keyboards, wireless keyboardsare available. These keyboards are poweredby batteries and send data to the computer

using a form of wireless technology. Infraredwireless keyboards communicate with thecomputer using infrared light waves (simi-lar to how a remote control communicateswith a TV). The computer receives theinfrared light signals through a specialinfrared port. The disadvantage of infraredkeyboards is that you need to point the key-board directly at the infrared port on thecomputer for it to work. Other wireless key-boards use radio frequency signals to trans-mit data, and many adhere to the Bluetoothstandard.

What are the best wireless key-boards? The best wireless keyboards senddata to the computer using radio frequency(RF). These keyboards contain a radio trans-mitter that sends out radio wave signals.These signals are received either by a smallreceiving device that sits on your desk andis plugged into the back of the computerwhere the keyboard would normally plugin, or in the case of Bluetooth-compatiblecomputers, by a receiving device containedin the system unit. Unlike infrared technol-ogy, RF technology doesn’t require that youpoint the keyboard at the receiver for it towork. RF keyboards used on home comput-ers can be placed as far as 6 to 30 feet fromthe computer, depending on their quality.

FIGURE 8

The stylus is the tabletPC’s primary inputdevice. You use it bytapping or writing onthe tablet’s touch-sensitive screen.

B I T S A N D B Y T E SKeystroke Shortcuts

You may know that youcan combine certain key-strokes to take short cutswithin the Windowsoperating system. Thefollowing are a few ofthe most helpful short-cuts to make more effi-cient use of your time.For more shortcuts forWindows-based PCs,visit http://support.microsoft.com. For a listof shortcuts for Macs, seewww. apple.com/support.

Text Formatting File Management Cut/Copy/Paste Windows Controls

CTRL+B Applies (orremoves) boldformatting toselected text

CTRL+I Applies (orremoves) italicformatting toselected text

CTRL+U Applies (orremoves)underlining toselected text

CTRL+O Opens theOpen dialog box

CTRL+N Opens anew document

CTRL+S Saves adocument

CTRL+P Opens thePrint dialog box

CTRL+X Cuts(removes) selectedtext from document

CTRL+C Copiesselected text

CTRL+V Pastesselected text(previously cut orcopied)

Alt+F4 Closes thecurrent window

Ctrl+Esc Opens theStart menu

Windows Key +F1 Opens WindowsHelp

Windows Key +F Opens the Search(Find Files) dialogbox

Input Devices

(Bluetooth devices have a much shorterrange.) RF keyboards used in business con-ference rooms or auditoriums can be placedas far as 100 feet away from the computer,but they are far more expensive than tradi-tional wired keyboards.

MICE AND OTHER POINTINGDEVICES

What kinds of mice are there? Themouse you’re probably most familiar with isthe optical mouse (see Figure 9a). An opticalmouse uses an internal sensor or laser todetect the mouse’s movement. The sensorsends signals to the computer, telling itwhere to move the pointer on the screen.Optical mice are often preferable to othertypes of mice because they have very fewmoving parts, which lessens the chances thatdirt will interfere with the mechanisms orthat parts will break down. Although opticalmice are most common now, you may stilluse a mouse at home or in school that has arollerball on the bottom, which moves whenyou drag the mouse across a mousepad. Themovement of the rollerball controls themovement of your cursor that appears onthe screen.

Mice also have two or three buttons thatenable you to execute commands and openshortcut menus. (Mice for Macs sometimeshave only one button.) Most new mice haveadditional programmable buttons andwheels that let you quickly scroll throughdocuments or Web pages.

Do mice still need mousepads?Optical mice will work on any surface with-out a mousepad, but some people still use apad to protect their furniture from beingmarred as the mouse moves. Trackball micealso don’t require mousepads. A trackballmouse (see Figure 9b) is basically a tradi-tional mouse that has been turned on itsback. The rollerball sits on top or on the sideof the mouse and you move the ball withyour fingers, allowing the mouse to remainstationary. A trackball mouse doesn’tdemand much wrist motion, so it’s consid-ered better for the wrist than an opticalmouse.

Are there wireless mice? Just asthere are wireless keyboards, there are wire-less mice, both optical and trackball. Wirelessmice are similar to wireless keyboards in thatthey use batteries and send data to the com-

puter by radio or light waves. If you alsohave an RF wireless keyboard, your RF wire-less mouse and keyboard usually can sharethe same RF receiver.

What about mice for notebooks?Most notebooks do not come with mice.Instead, they have integrated pointing devicessuch as a touchpad. A touchpad is a small,touch-sensitive area at the base of the key-board. To use the touchpad, you simply moveyour finger across the pad. Some touchpadsare also sensitive to taps, interpreting them asmouse-button clicks. Other notebooks incor-porate a trackpoint device, a small, joystick-like nub that allows you to move the cursorwith the tip of your finger. Figures 10a and10b show some of the mouse options you’llfind in notebooks.

Many people still prefer to use a tradi-tional external mouse with their notebooks.Small, compact devices like the MoGoMouse (see Figure 10c) are designed forportability. The MoGo Mouse fits into aperipheral slot on the side of a notebook;this slot serves to store the mouse, protect it,and charge its batteries all at the same time.

a

b

Trackball

Optical laser(sensor)

Wheel

FIGURE 9

(a) An optical mousehas an optical laser(or sensor) on the bot-tom that detects itsmovement. (b) A track-ball mouse turns thetraditional mouse onits back, allowing youto control the rollerballwith your fingers.

ACTIVE HELPDESKUsing Input Devices

In this Active Helpdesk call, you’ll play the role of a Helpdesk staffer,fielding calls about different input devices, such as the different miceand keyboards on the market, what wireless input options are avail-able, and how to best use these devices.

Looking at Computers: Understanding the Parts

The MoGo Mouse is wireless and usesBluetooth technology to transmit data to thenotebook.

What else can I do with mymouse? Manufacturers of mice are con-stantly releasing new models that allow youto perform ever more useful tasks with a fewclicks of the mouse. For example, on newmouse models, Microsoft and Logitech nowprovide features such as these:

• Instant Viewer. Shrinks all windowscurrently open to thumbnail-size imagesso that you can see everything open onyour desktop at a glance.

• Magnifier. Pulls up a magnification boxthat you can drag around the screen toenhance viewing of hard-to-read images(see Figure 11).

• Customizable buttons. Provides extrabuttons on the mouse that can be pro-grammed to perform the functions thatyou use most often to help you speedthrough tasks.

• Web Search. Allows you to quicklyhighlight a word or phrase and thenpress the search button (on the mouse)to start a Web search.

So check out the features of new miceas they come on the market to see if youcan benefit from the purchase of a newmouse.

Are game controls consideredmice? Game controls (such as joysticks,game pads, and steering wheels) are notmice per se, but they are considered inputdevices because they send data to the com-puter. Game pads, similar to the devicesused on gaming consoles (such as the Xbox360 and the PlayStation), are available forcomputers. Game pads have buttons andminiature pointing devices that provideinput to the computer. Force-feedbackjoysticks and steering wheels deliver data inboth directions: they translate your move-ments to the computer and translate itsresponses as forces on your hands, creating aricher simulated experience. If you like tomove around a lot while you play games,you can purchase wireless game controllersat most computer stores. Portable gamingdevices such as the Nintendo DS featuretouch-sensitive screens that use a stylus (orfinger) for input.

a

c

b

Trackpoint

Touchpad

Foot foldsflat forstorage

Windowprovidesmagnified

view

FIGURE 10

(a) This keyboardincorporates a track-point device that takesthe place of a mouse.(b) With a touchpadlike the one on thiskeyboard, you controlthe pointer by movingyour finger across thepad. The buttons atthe bottom of the key-board are used forright and left clicks ofthe mouse. (c) TheMoGo Mouse is sleek,compact, and batterypowered, making it aperfect companion ona business trip when aconventional mouse isdesired.

FIGURE 11

The magnifier is a new mouse feature that provides access to a window that canbe dragged around the screen to provide instant magnification of images or text.

Newton Peripherals, LLC

Input Devices

What other types of input devicesare available? Tablet PCs were developedprimarily because many people find it easierto write than type input into a computer. Buttablet PCs are expensive compared to con-ventional notebooks. An alternative is a digi-tal pen like the EPOS Digital Pen (see Figure12). This pen works in conjunction with aflash drive (a portable electronic storagedevice that connects to a port on a com-puter). You can write with the pen on anyconventional paper, and your writing is cap-tured and then wirelessly transmitted andstored in the flash drive. When the flashdrive is connected to a computer, you canuse software to translate your writing intodigital text.

IMAGE INPUT

How can I input digital images intomy computer? Digital cameras, cam-corders, and webcams are the most commondevices for capturing pictures and video,and are all considered input devices. Digitalcameras and camcorders are usually used inremote settings (away from the computer) tocapture images for later downloading to thecomputer. These devices are either connectedto the computer by a data cable or transmitdata wirelessly. Windows automatically rec-ognizes these devices when they are con-nected to the computer and makes the inputof the digital data to the computer very easy.

Webcams (see Figure 13) are small cam-eras that usually sit on top of your computermonitor (connected to the computer by acable) or are built into your notebook com-puter. Although some webcams are able tocapture still images, they are used mostly fortransferring live video directly to your com-puter. Webcams make it possible to transmitlive video over the Web and are often used tofacilitate videoconferencing or calls madewith video phones.Videoconferencing tech-nology allows a person sitting at a computerequipped with a personal video camera(webcam) and a microphone to transmitvideo and audio across the Internet (or othercommunications medium).

SOUND INPUT

Why would I want to input sound tomy computer? Equipping your computerto accept sound input opens up a variety ofpossibilities. You can conduct audio confer-

ences with work colleagues, chat with friendsor family over the Internet instead of using aphone, record podcasts, and more. Inputtingsound to your computer requires equippingit with a microphone or mic, a device thatallows you to capture sound waves (such asyour voice) and transfer them to digital for-mat on your computer. Many notebook com-puters come with built-in microphones, andsome desktop computers come with inexpen-sive microphones. If you don’t have a micro-phone or you aren’t getting the quality youneed from your existing microphone, youprobably need to shop for one.

What types of microphones areavailable for my computer? Mostmicrophones that are sold to be used withcomputers are magnetically shielded micro-phones, also known as computer micro-phones. The microphone plugs into a port onthe sound card in your computer, so makesure you select a microphone that has thecorrect connector to fit your available soundinput port.

Microphones come in two basictypes, depending on how they are con-figured to pick up sound.Unidirectional microphones pick upsound from only one direction. Theseare best used for recording podcasts witha single voice or making phone callsover the Internet with only one per-son on your end of the call.Omnidirectional microphones pickup sounds from all directions atonce. These mics are best for recording morethan one voice, such as during a conferencecall when you need to pick up the voices ofmultiple speakers.

What’s the best microphone tohave? This answer depends on what youare using the microphone to do. Close-talk

When you write onregular paper with

the pen, digitalinformation istransmitted

wirelessly to theflash drive.

Flashdrive

FIGURE 12

The EPOS digital pencaptures writing andstores it in a flashdrive for later transferto a computer. No typ-ing required!

FIGURE 13

Webcams, usuallyplaced on top of yourmonitor, enable you tobring live videostreams into yourcomputer to facilitatevideo chats or confer-ences with yourfriends or coworkers.

Logitech Inc.

Looking at Computers: Understanding the Parts

microphones (see Figure 14a), which are usu-ally attached to a headset, are useful in situa-tions such as using speech-recognition soft-ware, videoconferencing, or making

telephone calls. With amicrophone attached to aheadset, your hands arefree to perform othertasks while you speak

(such as making notes orreferring to paper docu-

ments). All computers partici-pating in a videoconference

need to have a micro-phone and speakers

installed so that partic-ipants can speak toand hear one another.

In speech-recognition sys-tems, you operate your computer through amicrophone, telling it to perform specificcommands (such as to open a file) or to trans-late your spoken words into data input.Speech recognition has yet to truly catch on,but its popularity is growing. In fact, it’sincluded in the software applications foundin Office 2007.

Handheld microphones (which often havea base attached) are convenient for recordingpodcasts or in other situations where youmight need your hands to be free. Clip-on(or lavaliere) microphones are useful in situ-ations where you are presenting at a meetingand need to keep your hands free for otheractivities (such as writing on a white board)or wander around the room. Many of thesemicrophones are wireless.

Are expensive microphones worththe money? Microphone quality varieswidely. For personal use, an inexpensivemicrophone is probably sufficient. However,if you plan to create professional productsand sell them to others, you’ll most likelyneed a more expensive professional record-ing studio microphone. Music stores andother stores that sell equipment for outfittingrecording studios are usually good places toobtain advice on high-quality microphones.

INPUT DEVICES FOR PHYSICALLYCHALLENGED INDIVIDUALS

What input devices are available forpeople with disabilities? Individualswith physical challenges often use comput-

ers, but sometimes they need special inputdevices to access them. For visually impairedusers, voice recognition is an obvious option.For those users whose visual limitations areless severe, keyboards with larger keys areavailable. On-screen keyboards also canmake input easier for some individuals.These keyboards are displayed as graphicson the computer screen and represent a stan-dard keyboard layout. Keys are pressed withthe use of a pointing device or by using atouch-screen monitor.

People with motor control issues mayhave difficulty with pointing devices. To aidsuch users, special trackballs are availablethat are manipulated easily with one fingerand are attachable to almost any surface(such as a workstation or wheelchair). Whenarm motion is severely restrained, head-mounted pointing devices can be used.Generally, these involve a camera mountedon the computer monitor and a deviceattached to the head (often installed in ahat). When the user moves his or her head,the camera detects the movement that con-trols the cursor on the screen. In this case,mouse clicks are controlled by a switch thatcan be manipulated by the user’s hands orfeet or even by using an instrument that fitsinto the mouth and senses the user blowinginto it.

Output DevicesOutput devices enable you to sendprocessed data out of your computer. Thiscan take the form of text, pictures (graphics),sounds (audio), and video. One commonoutput device is a monitor (sometimesreferred to as a display screen), which dis-plays text, graphics, and video as soft copies(copies you can see only on-screen). Anothercommon output device is the printer, whichcreates tangible or hard copies (copies youcan touch) of text and graphics. Speakersand earphones (or ear buds) are obviouslythe output devices for sound.

MONITORS

What are the different types of moni-tors? There are two basic types of moni-tors: CRTs and LCDs. If your monitor lookslike a traditional television set, it has a picturetube device called a cathode-ray tube (CRT)

FIGURE 14

Headset and desktopmicrophones offerconvenient, inexpen-sive, hands-free voiceinput.

Output Devices

like the one shown in Figure 15a. If yourmonitor is flat, such as those found innotebooks, it’s using liquid crystal dis-play (LCD) technology (see Figure 15b),similar to that used in digital watches.LCD monitors (also called flat-panel mon-itors) are lighter and more energy efficientthan CRT monitors, making them perfectfor portable computers such as notebooks.The sleek style of LCD monitors alsomakes them a favorite for users with smallworkspaces.

Which monitor type is most popu-lar? By far, LCD monitors are the mostpopular. In fact, CRT monitors can be diffi-

cult to find even if you want to buy one asthey are fast becoming legacy technology.Legacy technology is comprised of com-puting devices or peripherals that use tech-niques, parts, and methods from an earliertime that are no longer popular. Althoughlegacy technology may still be functional,it is quickly being replaced by newer tech-nological advances. This doesn’t mean thatif you have a CRT monitor that is function-ing well you should throw it away and buyan LCD monitor. But when your CRT mon-itor begins to fail, you will most likelywant to consider replacing it with newertechnology.

E T H I C S I N I TEthics: What Is Ethical Computing?

If you were asked to cite an example of unethical behav-ior while using a computer, you probably wouldn’thave trouble providing an answer. You’ve probablyheard news stories about crimes conducted using com-puters, such as people unleashing viruses or commit-ting identity theft. You may have read about studentswho were prosecuted at a neighboring university forillegally sharing copywrited material such as videos.Both of these are examples of unethical behavior whileusing a computer. But if you were asked what consti-tutes ethical behavior while using a computer, couldyou provide an answer just as quickly?

Loosely defined, ethics is a system of moral princi-ples, rules, and accepted standards of conduct. So whatare the accepted standards of conduct when using com-puters? The Computer Ethics Institute developed theTen Commandments of Computer Ethics, which iswidely cited as a benchmark for companies that aredeveloping computer usage and compliance policies foremployees. Our Ethical Computing Guidelines listedbelow are based the Computer Ethics Institute’s work:

Ethical Computing Guidelines

1. Avoid causing harm to others when using computers.2. Do not interfere with other people’s efforts at accom-

plishing work with computers.3. Resist the temptation to snoop in other people’s

computer files.4. Do not use computers to commit theft.5. Agree not to use computers to promote lies.6. Do not use software (or make illegal copies for oth-

ers) without paying the creator for it.

7. Avoid using other people’s computer resourceswithout appropriate authorization or proper com-pensation.

8. Do not claim other people’s intellectual output asyour own.

9. Consider the social consequences of the products ofyour computer labor.

10. Only use computers in ways that show considera-tion and respect for others.

The United States has enacted laws that supportsome of these guidelines, such as Number 6—the break-ing of which would violate copyright laws. Or Number4, which is covered by numerous federal and state lar-ceny laws. Other guidelines, however, require moresubtle interpretation as to their unethical nature becausethere are no laws designed to enforce them.

Consider the seventh guideline against using unau-thorized resources, for example. The college you attendprobably provides computer resources for you to com-plete coursework. However, just because you are providedwith a computer and access to the Internet doesn’t nec-essarily mean it is ethical for you to run a business oneBay in between classes or on the weekends in the col-lege library. Although it might not be technically illegal,you are tying up computer resources that could be usedby other students for the intended purpose of learningand completing coursework (which, of course, also vio-lates guidelines 2 and 10).

Throughout the chapters in this book, we’ll touch onmany topics related to these guidelines. So keep them inmind as you study, and think about how they relate tothe actions you take as you use computers in your life.

Looking at Computers: Understanding the Parts

Key Monitor FeaturesHow do monitors work? Monitorscreens are grids made up of millions ofpixels, or tiny dots (see Figure 16). Simplyput, illuminated pixels are what create theimages you see on your monitor. There arethree pixel colors: red, blue, and green.LCD monitors are made of two (or more)sheets of material filled with a liquid crys-tal solution. A fluorescent panel at theback of the LCD monitor generates lightwaves. When electric current passes

through the liquid crystal solution, thecrystals move around, either blocking thefluorescent light or letting the light shinethrough. This blocking or passing of lightby the crystals causes images to be formedon the screen. In CRT monitors, pixels areilluminated by an electron beam thatpasses back and forth across the back ofthe screen very quickly so that the pixelsappear to glow continuously. The variouscombinations of red, blue, and green makeup the components of color we see on ourmonitors.

What factors affect the quality ofan LCD monitor? The most importantfactor to consider when choosing an LCDmonitor is resolution. The clearness orsharpness of the image—its resolution—iscontrolled by the number of pixels dis-played on the screen. The higher the reso-lution, the sharper and clearer the imagewill be. Monitor resolution is listed as anumber of pixels. A high-end monitor mayhave a native (or maximum) resolution of1,600 x 1,200, meaning it contains 1,600vertical columns with 1,200 pixels in eachcolumn. Note that you can adjust a moni-tor’s resolution either to make the screendisplay larger (reducing the resolution) orto fit more on your screen (increasing theresolution). You cannot increase the reso-lution of an LCD monitor beyond itsnative resolution. Generally, you shouldselect a monitor with the highest resolu-tion available for the screen size (mea-sured in inches).

You’ll generally find two types of LCDmonitors on the market: passive-matrixdisplays and active-matrix displays. Lessexpensive LCD monitors use passive-matrix displays, whereas more expensivemonitors use active-matrix displays.Passive-matrix technology uses an electri-cal current passed through the liquid crys-tal solution to charge groups of pixels,either in a row or a column. This causesthe screen to brighten with each pass ofelectrical current and subsequently fade.With active-matrix displays, each pixel ischarged individually, as needed. The resultis that an active-matrix display produces aclearer, brighter image with better viewingangles. As the price of active-matrix dis-plays continues to drop, passive-matrix dis-plays will soon become a thing of the past.

a b

Single CRTpixel

Single LCDpixel

a

b

FIGURE 15

(a) CRT monitors arebig and bulky and looklike television sets. (b)LCDs (flat-panel moni-tors) save preciousdesktop space andweigh considerablyless than CRT monitors.

FIGURE 16

A pixel, short for picture element, is one dot. CRT pixels (a) are round, whereasLCD pixels (b) are rectangular and are laid out in a matrix. There are three pixelcolors: red, blue, and green. Millions of pixels make up an image, and color is cre-ated by various shades and combinations of these pixels.

Output Devices

Other factors to consider when judgingthe quality of an LCD monitor are as follows:

• Viewing angle. An LCD’s viewingangle, which is measured in degrees,tells how far you can move to the side of(or above or below) the monitor beforethe image quality degrades to unac-ceptable levels. For monitors that mea-sure 17 inches or more, a viewingangle of at least 150 degrees is usuallyrecommended.

• Contrast ratio. This is a measure of thedifference in light intensity between thebrightest white and the darkest blackcolors that the monitor can produce. Ifthe contrast ratio is too low, colors tendto fade when you adjust the brightnessto a high or low setting. A contrast ratioof between 400:1 and 600:1 is preferable.

• Brightness. Measured as candelas persquare meter (cd/m2) or nits, brightnessis a measure of the greatest amount oflight showing when the monitor is dis-playing pure white. A brightness level of250cd/m2 or greater is recommended.

• Response time. This is the measure-ment (in milliseconds) of the time ittakes for a pixel to change color. Thelower the response time, the smoothermoving images will appear on the moni-tor. A low response time is importantwhen using a monitor to play a game ordisplay full-motion video (such asmovies or television).

LCD VERSUS CRT

Why did LCD monitors become somuch more popular than CRT moni-tors? LCD monitors are much smaller thanCRT monitors and therefore take up far lessspace on a desktop. LCD monitors are alsogenerally brighter than CRT monitors anduse different refresh methods for their pixels,which causes less eyestrain. Another advan-tage is that LCD monitors use significantlyless energy and emit less electromagneticradiation, making them more environmen-tally friendly. And finally, LCD monitorsweigh less, making them the obvious choicefor mobile devices.

CRT monitors used to offer a wider rangeof resolutions than LCD monitors and pro-duced better clarity and color accuracy.However, the newest LCD monitors haveclosed the gap with the old CRTs in all of

these areas and are now considered excellentsubstitutes for CRT monitors by most users.

Because of their different technologies,you can see more with an LCD screen thanyou can with the same-size CRT monitor.For example, there are 17 inches of viewablearea on a 17-inch LCD monitor but only 15inches of viewable area on a 17-inch CRTmonitor.

What features of monitors canhelp physically challenged individu-als? If a monitor (or display in a notebookor PDA) accepts input from a user touchingthe screen, then the monitor also doubles asan input device. Although these monitors,known as touch-screen monitors, are avail-able for home computers, they are uncom-mon. However, people with limited motorcontrol that prevents them from typingquickly and accurately are often greatlyassisted by the installation of a touch-screenmonitor. In fact, people with significantparalysis often use a stylus (sometimes heldin their mouth) in conjunction with a touch-screen monitor to virtually eliminate theneed for a keyboard.

B I T S A N D B Y T E SCleaning Your Monitor

Have you ever noticed how quickly your monitor attracts dust?It’s important to keep your monitor clean because dust buildupcan act like insulation, keeping heat in and causing the electroniccomponents to wear out much faster. To clean your monitor, fol-low these steps:

1. Turn off the monitor and make sure it is unplugged from theelectrical power outlet.

2. For a CRT monitor, wipe the monitor’s surface using a sheet offabric softener or a soft cloth dampened with window cleaneror water. Never spray anything directly onto the monitor.(Check your monitor’s user manual to see if there are cleaningproducts you should avoid using.) For an LCD (flat-panel)monitor, use a 50/50 solution of rubbing alcohol and water ona soft cloth and wipe the screen surface gently.

3. In addition to the screen, wipe away the dust from around thecase.

Finally, don’t place anything on top of the monitor because theitems may block air from cooling it, and avoid placing magnets(including your speaker system’s subwoofer) anywhere near themonitor because they can interfere with the mechanisms insidethe monitor.

Looking at Computers: Understanding the Parts

Individuals with impaired vision canreduce the resolution of a monitor, whichcauses the images on the screen (like iconsand text) to appear larger. Windows andmany other software applications have mag-nification features that can further enhanceviewing.

How do I show output to a largegroup of people? Crowding large groupsof people around your computer just isn’tpractical. Data projectors are devices thatare used to project images from your com-puter onto a wall or viewing screen. Dataprojectors are commonly used in businessand education in conference rooms andclassrooms. These projectors are becomingsmaller and lighter, making them ideal forbusinesspeople who have to make presenta-tions at client locations. The price of theseprojectors has been falling significantly inrecent years, making them a good option foruse in the home. Projectors like theZoombox Entertainment Project fromHasbro (see Figure 17) can not only project a60-inch image on a screen (or wall) but alsocan play CDs and DVDs with the built-inDVD combo drive and speakers—all for lessthan $300.

PRINTERS

What are the different types of print-ers? There are two primary categories ofprinters: impact and nonimpact. Impactprinters have tiny hammer-like keys thatstrike the paper through an inked ribbon, thusmaking a mark on the paper. The most com-mon impact printer is the dot-matrix printer.In contrast, nonimpact printers spray ink oruse laser beams to transfer marks onto thepaper. The most common nonimpact printersare inkjet printers and laser printers. Suchnonimpact printers have replaced dot-matrixprinters almost entirely. They tend to be lessexpensive, quieter, and faster, and they offerbetter print quality. The only place you maystill see a dot-matrix printer is at a company(like a car rental agency) that still uses them toprint multipart forms. Dot-matrix printers aretruly legacy technology.

What are the advantages of inkjetprinters? Compared with dot-matrix print-ers, inkjet printers (see Figure 18) are quieter,faster, and offer higher-quality printouts. Inaddition, even high-quality printers areaffordable. Inkjet printers work by sprayingtiny drops of ink onto paper. The key advan-tage is that inkjets print acceptable qualitycolor images cost effectively. In fact, whenusing the right paper, higher-end inkjet print-ers print images that look like professional-quality photos. Because of their high qualityand low price, inkjet printers are still themost popular printer for color printing.

FIGURE 17

Inexpensive projectors such as the Zoombox are showing up more frequently inthe home.

ACTIVE HELPDESKUsing Output Devices

In this Active Helpdesk call, you’ll play the role of a Helpdesk staffer,fielding calls about different output devices, including the differencesbetween LCD and CRT monitor technologies and between inkjet andlaser printers and the advantages and disadvantages of each.

FIGURE 18

Inkjet printers are popular among home users, espe-cially with the rise of digital photography. Manyinkjet printers are optimized for printing photos fromdigital cameras.

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Output Devices

Why would I want a laserprinter? Laser printers are often pre-ferred for their quick and quiet productionand high-quality printouts (see Figure 19).Because they print quickly, laser printers areoften used in schools and offices wheremultiple computers share one printer.Although more expensive to buy than inkjetprinters, over the long run, for high-volumeprinting, laser printers are more economicalthan inkjets (they cost less per printedblack-and-white page) when you includethe price of ink and special paper in theoverall cost. Recently, the prices of colorlaser printers have fallen dramatically, mak-ing them very price competitive with high-end inkjet printers.

What kind of printer could I use formy notebook? Although any printer thatis suitable for your desktop is appropriate touse with your notebook, you may want toconsider a portable printer for added mobil-ity and flexibility (see Figure 20). Portableprinters (including many inkjet printers)often are compact enough to fit in a brief-case, are lightweight, and sometimes run onbattery power instead of AC current.

FIGURE 19

Laser printers print quickly and offer high-qualityprintouts. Models that print color at prices afford-able enough for personal use or a small business arebecoming more common.

FIGURE 20

Modern portable print-ers feature Bluetoothconnectivity, allowingthem to be used withmobile devices suchas notebooks, tablets,PDAs, and smart-phones.

FIGURE 21

Plotters are largeprinters used to printoversize images,maps, or architecturalplans.

Are there wireless printers? Infrared-compatible or wireless printers allow you toprint from your handheld device, notebook,or camera. Most of these printers work usingBluetooth technology.

Are there any other types of spe-cialty printers? A multifunction printer,or an all-in-one printer, is a device that com-bines the functions of a printer, scanner,copier, and fax into one machine. Popular fortheir space-saving convenience, all-in-oneprinters can be either inkjet or laser-based.Plotters are large printers used to produceoversize pictures that require precise contin-uous lines to be drawn, such as maps,images (see Figure 21), or architectural plans.Plotters use a computer-controlled pen thatprovides a greater level of precision than the

Paper exits here

Courtesy Xerox Corporation

NewsCom

Hewlett-Packard Company

Looking at Computers: Understanding the Parts

series of dots that laser or inkjet printersare capable of making.

Thermal printers, such as the oneshown in Figure 22, are another

kind of specialty printer. Theseprinters work either by melting

wax-based ink onto ordinarypaper (in a process called

thermal wax transferprinting) or by burningdots onto speciallycoated paper (in a

process called directthermal printing). They are

used in stores to print receipts andin airports for electronic ticketing, among

other places. Thermal printers are alsoemerging as a popular technology formobile and portable printing, for example,in conjunction with PDAs and similardevices. These are the printers car rental

agencies use to give you an instant receiptwhen you drop off your rental car. Manymodels feature wireless infrared technologyfor complete portability.

Choosing a PrinterHow do I select the best printer? Websites such as www.printerdb.com/ColorPrinter.html provide excellent tips on selecting aprinter appropriate for your needs. Youshould conduct research before buying aprinter, and be sure to consider these factorswhen making your choice:

• Speed. A printer’s speed determineshow many pages it can print per minute(called pages per minute, or ppm). Thespeed of inkjet printers has improvedover the years so that many inkjet print-ers now print as fast as laser printers.Printing speeds vary by model andrange from 8 to 30 ppm for both laserand inkjet printers. Text documentsprinted in black and white print fasterthan documents printed in color.

• Resolution. A printer’s resolution (orprinted image clarity) is measured indots per inch (dpi), or the number of dotsof ink in a one-inch line. The higher thedpi, the greater the level of detail andquality of the image. You’ll sometimessee dpi represented as a horizontal num-ber multiplied by a vertical number,such as 600 × 600, but you may also seethe same resolution simply stated as 600dpi. For general-purpose printing, 300dpi is sufficient. If you’re going to printphotos, 1,200 dpi is better. The dpi forprofessional photo-quality printers istwice that.

• Color output. If you’re using an inkjetprinter to print color images, buy a four-color (cyan, magenta, yellow, and black)or six-color printer (four-color plus lightcyan and light magenta) for the highest-quality output. Some printers come witha single ink cartridge for all colors; oth-ers have two ink cartridges, one forblack and one for color. The best setup isto have individual ink cartridges foreach color so you can replace only thespecific color cartridge that is empty.Color laser printers have four separatetoner cartridges (black, cyan, magenta,and yellow), and the toner is blended invarious quantities to produce the entireprinter spectrum.

B I T S A N D B Y T E SDoes It Matter What Paper I Print On?

The quality of your printer is only part of what controls the quality ofa printed image. The paper you use and the printer settings that con-trol the amount of ink used are equally important. If you’re printingtext-only documents for personal use, using low-cost paper is fine.You also may want to consider selecting “Draft” mode in yourprinter setting to conserve ink. However, if you’re printing docu-ments for more formal use, such as résumés, you may want to adjustyour print settings to “Normal” or “Best” and choose a higher-quality paper. Paper quality is determined by the paper’s weight,whiteness, and brightness.

The weight of paper is measured in pounds, with 20 pounds beingstandard. A heavier paper may be best for projects such asbrochures, but be sure to check that your printer can handle theadded thickness. It is a matter of personal preference as to the degreeof paper whiteness. Generally, the whiter the paper, the brighter col-ors appear. However, in some more formal printings such asrésumés, you may want to use a creamier color. The brightness ofpaper usually varies from 85 to 94. The higher the number, thebrighter the paper and the easier it is to read printed text. Opacity isespecially important if you’re printing on both sides of the paper,because it determines the amount of ink that shows through or isconcealed from the opposite side of the paper.

If you’re printing photos, paper quality can have a big impacton the results. Photo paper is more expensive than regular paperand comes in a variety of textures ranging from matte to highgloss. For a photo-lab look, high-gloss paper is the best choice.Semigloss (often referred to as satin) is good for portraits, while amatte surface is often used for black-and-white printing.

FIGURE 22

Thermal printers areideal for mobile com-puting because theyare compact and light-weight, and require noink cartridges. Hereyou see a PDA set intoa thermal printer.

Output Devices

D I G D E E P E RHow Inkjet and Laser Printers Work

Ever wonder how a printer knows what to print andhow it puts ink in just the right places? Most inkjetprinters use drop-on-demand technology in which theink is “demanded” and then “dropped” onto the paper.Two separate processes use drop-on-demand technol-ogy: thermal bubble, used by Hewlett-Packard andCanon, and piezoelectric, used by Epson. The differencebetween the two processes is how the ink is heatedwithin the print cartridge reservoir (the chamber insidethe printer that holds the ink).

In the thermal bubble process, the ink is heated insuch a way that it expands (like a bubble) and leaves thecartridge reservoir through a small opening, or nozzle.Figure 23 shows the general process for thermal bubble.

In the piezoelectric process, each ink nozzle containsa crystal at the back of the ink reservoir that receives an

electrical charge, causing the ink to vibrate and drop outof the nozzle.

Laser printers use a completely different process.Inside a laser printer is a big metal cylinder (or drum)that is charged with static electricity. When you ask theprinter to print something, it sends signals to the laserin the laser printer, telling it to “uncharge” selectedspots on the charged cylinder, corresponding to the doc-ument you wish to print. Toner, a fine powder that isused in place of liquid ink, is attracted to only thoseareas on the drum that are not charged. (Theseuncharged areas are the characters and images youwant to print.) The toner is then transferred to the paperas it feeds through the printer. Finally, the toner ismelted onto the paper. All unused toner is swept awaybefore the next job starts the process all over again.

The print cartridge ispositioned inside yourinkjet printer so that theprint head faces downtoward the paper. Theprint head has 50 toseveral hundred nozzles,or small holes, throughwhich ink droplets fall. These nozzles are narrower than a human hair. Insidethe print head of color inkjet printers, there are three ink reservoirs that holdmagenta (red), cyan (blue), and yellow ink. Depending on your printer, a fourthink reservoir may be required to hold black ink, as well. (In non-color inkjetprinters, there is only one ink reservoir for the black ink.)

STEP (1): Once the printer receives thecommand to print, electricalpulses flow through thinresistors in the print head toheat the ink.

STEP (2): The heated ink forms a bubble. The bubble continuesto expand until it is forcedout of the nozzle.

STEP (3): The ink drops onto the paper.

STEP (4): As the ink leaves the cartridge,the chamber begins to cooland contract, creating a vacuum to draw in the ink forthe process to begin again.

(4)(3)

(2)(1)

Inverted print cartridge

Print cartridges

InkResistor

Nozzle

Firingchamber

Print head

Nozzles

Inkjet Printer

Ink forcedout of

the nozzle

Bubbleforming

Ink drop Ink dot

FIGURE 23

How a thermal bubbleinkjet printer works.

Looking at Computers: Understanding the Parts

• Memory. Printers need memory inorder to print. Inkjet printers run slowlyif they don’t have enough memory. Ifyou plan to print small text-only docu-ments on an inkjet printer, 1 to 2megabytes (MB) of memory should beenough. You need about 4 MB of mem-ory if you expect to print large text-onlydocuments and 8 MB if you printgraphics-heavy files. Unlike inkjetprinters, laser printers won’t print at allwithout sufficient memory. To ensureyour laser printer meets your printingneeds, buy one with 16 MB of memory.Some printers allow you to add morememory later.

• Use and cost of the printer. If you willbe printing mostly black-and-white,text-based documents or will be sharingyour printer with others, a black-and-white laser printer is best because of itsprinting speed and overall economiesfor volume printing. If you’re planningto print color photos and graphics, aninkjet printer or color laser printer is amust, even though the cost per page willbe higher.

• Cost of consumables. You should care-fully investigate the cost of consumables(such as printer cartridges and paper)for any printer you are considering pur-chasing. Often, the cost of inkjet car-tridges can exceed the cost of the actualprinter when purchased on sale. Check

reviews in consumer magazines (such asPC Magazine or Consumer Reports) tohelp you evaluate the overall cost ofproducing documents with a particularprinter.

SOUND OUTPUT

What are the output devices forsound? As noted earlier, most computersinclude inexpensive speakers as an outputdevice for sound. These speakers are suffi-cient to play the standard audio clips youfind on the Web and usually enable you toparticipate in videoconferencing or phonecalls made over the Internet. However, if youplan to digitally edit audio files or are partic-ular about how your music sounds, you maywant to upgrade to a more sophisticatedspeaker system, such as one that includessubwoofers (special speakers that produceonly low bass sounds) and surround-soundcapability (speaker systems set up in such away that they surround you with sound).And wireless speaker systems are availablenow to help you avoid cluttering up yourrooms with speaker wire!.

If you work in close proximity to otheremployees or are traveling with a notebook,you may need to use headphones (or earbuds) for your sound output to avoid dis-tracting other people. Headphones will pluginto the same jack on the computer thatspeakers are connected to, so using themwith a computer is easy. Studies of users ofMP3 players have shown that hearing mightbe damaged by excessive volume, especiallywhen using ear buds because they fit intothe ear canals. Therefore, you should exer-cise caution when using these devices.

The System UnitWe just looked at the components of yourcomputer that you use to input and outputdata. But where does the processing takeplace and where is the data stored? The sys-tem unit is the box that contains the centralelectronic components of the computer,including the computer’s processor (its brain),its memory, and the many circuit boards thathelp the computer function. You’ll also findthe power source and all the storage devices(CD/DVD drive and hard drive) here.

B I T S A N D B Y T E SMaintaining Your Printer

In general, printers require very little maintenance. Occasionally,it’s a good idea to wipe the case of the printer with a damp clothto free it from accumulated dust. However, do not wipe away anyink residue that has accumulated inside the printer. If you areexperiencing streaking or blank areas on your printed paper, yourprint head nozzles may be clogged. To fix this, run the printer’scleaning cycle. (Check your printer’s manual for instructions,because every printer is different.) If this doesn’t work, you maywant to use a cleaning sheet to brush the print head clean. Thesesheets often come with printers or with reams of photo paper. Ifyou still have a problem, try a cleaning cartridge. Cleaning car-tridges contain a special fluid that scrubs the print head. Such car-tridges can be found where most ink cartridges are sold (justmake sure you buy one that is compatible with your printer).

The System Unit

Which is the best system unitstyle? Most system units on desktop com-puters are tower configurations, which typi-cally stand vertically (see Figure 24a). Somecreatively designed desktop system units,such as the Apple iMac (see Figure 24b),house not just the computer’s processor andmemory, but its monitor as well. Although theall-in-ones like the iMac take up less desktopspace, tower configurations make it easier foryou to expand your computer. This is becausemost tower configurations have empty areasthat allow you to install additional storagedrives, such as an additional DVD or CDdrive that didn’t come with your system.

ON THE FRONT PANEL

What’s on the front panel of my com-puter? No matter whether you choose adesktop or tower design, the front panel ofyour computer provides you with access topower controls and the storage devices onyour computer. Figure 25 shows the frontpanel of a typical system. Although your sys-tem might be slightly different, chances are itincludes many of the same features.

Power ControlsWhat’s the best way to turn my com-puter on and off? Your system has apower-on button on the front panel. (You mayalso find power-on buttons on some key-boards.) Although you use this button to turnon your system, you don’t want to use it toturn off (or power off) your system. Modernoperating systems want control over the shut-down procedure, so you turn off the powerby clicking on a shutdown icon on the desk-top, not by pushing the main power button.

If you do shut off the power using themain power button without shutting downyour operating system first, nothing on yoursystem will be permanently damaged.However, some files and applications maynot close properly, so the operating systemmay need to do some extra work the nexttime you start your computer.

Should I turn off my computerevery time I’m done using it? Somepeople say you should leave your computeron at all times. They argue that turning yourcomputer on and off throughout the day sub-jects its components to stress as the heating

a

b

FIGURE 24

System units come inseveral differentdesigns. (a) A stan-dard tower configura-tion takes up moreroom than (b) theApple iMac with theIntel Core 2 Duo.However, the closediMac cannot be easilyupgraded.

Powerbutton

CD/RW drive

DVD/RW drive

Memory cardreader (optional)

Productivityports: audio,FireWire, USB

Floppy drive(optional)

FIGURE 25

The front panel of your computer provides you withaccess to power controls as well as to the storagedevices on your computer.

Dell, Inc. Apple Computer, Inc.

Looking at Computers: Understanding the Parts

and cooling process forces the components toexpand and contract repeatedly. Otherpeople say you should shut down yourcomputer when you’re not using it. Theyclaim that you’ll end up wasting moneyon electricity to keep the computer run-ning all the time. However, modern oper-ating systems include power-managementsettings that allow the most power-hungrycomponents of the system (the hard driveand monitor) to shut down after a shortidle period.

If you use the computer sporadicallythroughout the day, it may be best to keep iton while you’re apt to use it and power itdown when you’re sure you won’t be usingit for long periods. However, if you useyour computer only for a little while eachday; you’ll be paying electricity charges

during long periods of nonuse. If you’retruly concerned about the stresses incurredfrom powering on and off your computer,you may want to buy a warranty with thecomputer.

Can I “rest” my computer withoutturning it off completely? As men-tioned earlier, your computer has power-management settings that help it conserveenergy. In Windows Vista, the two mainmethods of power management are Sleepand Hibernate. When your computerenters Sleep mode, all the documents,applications, and data you were using arein RAM (memory) where they are quicklyaccessible upon starting to use your com-puter again (in Windows XP this wascalled Standby).

Hibernation is another power-savingmode that stores your data in memory andsaves it to your computer’s hard disk. Ineither mode, the computer then enters astate of greatly reduced power consumptionto save energy. But a big advantage to usingHibernate is that if there is a power failurewhile your computer is conserving power,your information is protected from loss,because it is saved on the hard drive. To putyour computer to sleep (or hibernate), openthe Start menu and click the power button.To wake up your computer, tap a key on thekeyboard or move the mouse; in a few sec-onds, the computer resumes with exactly thesame programs running and documents dis-played as when you put the computer tosleep.

In Windows Vista, you can change whathappens when you press the power buttonon the Start menu. By accessing the PowerOptions screen (see Figure 26), you candecide if you want your computer to sleepor hibernate when you click the powerbutton.

What’s the restart option inWindows for? If you’re using WindowsVista, you have the option to restart thecomputer when you click the right arrowbutton next to the lock button on the Startmenu (see Figure 27). Restarting the systemwhile it’s powered on is called a warmboot. You might need to perform a warmboot if the operating system or other soft-ware application stops responding or if youhave installed new programs. It takes lesstime to perform a warm boot than to powerdown completely and then restart all ofyour hardware.

FIGURE 26

Using the Sleep and Hibernation settings is not only good for the environment, butit is also good for your wallet. Windows Vista allows you to control the sleep andhibernation settings for a variety of operations.

>Open Power Options by left-clicking the Start button, clicking Control Panel, andthen clicking Power Options. On the Select a power plan page, click Change plansettings under the selected plan. On the Change settings for the plan page, clickChange advanced power settings. On the Advanced settings tab, expand Powerbuttons and lid, expand Start menu power button, click On battery or Plugged in (orboth), click the arrow, and then click Sleep, Hibernate, or Shut Down.

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The System Unit

Starting your computer when it has beencompletely powered down, such as firstthing in the morning, is a cold boot. Withthe power management options of WindowsVista, however, you really need to shutdown your computer completely only whenyou need to repair or install hardware in thesystem unit or move the system unit toanother location.

Drive Bays: Your Access to StorageDevices

What else is on the front panel?Besides the power button, the other featuresthat can be seen at the front of your systemunit are drive bays. These bays are specialshelves reserved for storage devices, thosedevices that hold your data and applicationswhen the power is shut off. There are twokinds of drive bays:

1. Internal drive bays cannot be seen oraccessed from outside the system unit.Generally, internal drive bays arereserved for internal hard disk drives(or just hard drives). An internal harddrive usually holds all permanentlystored programs and data.

2. External drive bays can be seen andaccessed from outside the system unit.External drive bays house CD and DVDdrives, for example. Empty externaldrive bays are covered by a faceplate.

By looking at the front panel of your sys-tem unit, you can tell which devices havebeen installed, and often how many baysremain available for expansion.

What kind of data is saved on theinternal hard disk drive? The harddisk drive is your computer’s primarydevice for permanent storage of softwareand documents. The hard disk drive is anonvolatile storage device, meaning it holdsthe data and instructions your computerneeds permanently, even after the computeris turned off. Today’s internal hard drives,with capacities of up to 750 GB, can holdmore data than would fit in the books inyour neighborhood library.

Originally, all hard disk drives wereinstalled inside the system unit with all theother drive bays (see Figure 28a). However,unlike the other drive bays, you can’taccess an internal hard disk drive from theoutside of the system unit, making it a formof nonportable permanent storage. Today,external hard drives are readily available.

a b

FIGURE 28

(a) Internal hard drives usually hold all the data and instructions that the computerneeds, even after the power is turned off. Although the photo here shows an openinternal hard disk drive, the drives are actually enclosed within the system unit in a her-metically sealed protective case to prevent contamination. In fact, a smoke or dust par-ticle is enough to crash a hard drive. (b) External hard drives reside outside the systemunit and are connected via cables, usually through a USB or Firewire data port.Because they are portable, they can easily be used for backing up multiple computers.

FIGURE 27

When you select the right arrow button from theStart menu in Windows Vista, you are presentedwith several options. For a warm boot, chooseRestart. To power down the computer completely,choose Shut Down. You can also put your com-puter into a lower power mode by selecting Sleepor Hibernate.

>Click the Start menu button in the taskbar and thenclick the right arrow button to access your options.

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Looking at Computers: Understanding the Parts

are the new alternative to storing portabledata (see Figure 29). These devices originallywere about the size of your thumb, but nowthey vary in size and can hold upwards of12 GB of data. Flash drives convenientlyplug into universal serial bus (USB) ports.

Several manufacturers now also includeslots on the front of the system unit in whichyou can insert portable flash memory cardssuch as Memory Sticks and CompactFlashcards. Many notebooks also include slots forflash memory cards. Flash memory cards letyou transfer digital data between your com-puter and devices such as digital cameras,PDAs, smartphones, video cameras, andprinters. Although incredibly small—someare just the size of a postage stamp—thesememory cards have capacities that match orexceed that of a CD.

Figure 30 shows the storage capacities ofthe various portable storage media used inyour computer’s drive bays. As you learnedearlier in this chapter, storage capacity ismeasured in bytes.

PortsWhat are the ports on the front of mycomputer for? Ports are the place on thesystem unit where peripheral devices attachto the computer so that data can beexchanged between them and the operatingsystem. Traditionally, ports have beenlocated on the back of the system unit.However, in many new computer models,some commonly used ports are placed onthe front of the computer for easier accesswhen connecting portable devices such asdigital cameras, MP3 players, and PDAs tothe computer.

ON THE BACK

Are there still ports on the back ofmy system unit? Yes, even more portsare located on the back of your system unit,and often they duplicate ports that are pro-vided on the front. Peripheral devices, suchas monitors, printers, keyboards, and mice,connect to the system unit through ports.Because peripheral devices exchange datawith the computer in various ways, a num-ber of different ports have been created toaccommodate these devices (see Figure 31)on the back of desktop systems. Notebookshave a similar selection of ports (see Figure

FIGURE 29

(a) Classic style flashdrives are about thesize of your thumb andcan hold up to 8 GB ofdata (or more). (b) Now available arelarger versions offlash drives that canhold 16 GB of data (or more).

External hard drives (see Figure 28b) areessentially internal hard drives that have

been made portable by enclosing them ina protective case, enabling them to

easily connect to computers viacables, and by making them smalland lightweight. External hard

drives are usually connected toyour computer with a data transfer

cable. They are often used to back up(make a copy of) data that is containedon the internal hard drive in case aproblem develops with the internalhard drive and data needs to be recov-ered.

What kinds of external drivebays do most PCs have? On thefront panel, you’ll see one or two baysfor other storage devices such as CD dri-ves. CD-ROM drives read CDs,whereas CD-RW drives can both read

from and write (record) data to CDs. Somecomputers may also come with a separateDVD drive, which allows them to playDVDs and CDs, or a DVD-RW drive, whichallows them to both read and write DVDs.DVDs are the same size and shape as CDsbut can hold more than 25 times as muchdata. DVD-RW drives are especially useful ifyou’re creating digital movies. Today, manycomputers come with a “combo” CD-RW/DVD drive, a device that can read and writeCDs and play DVDs.

Blu-ray is the latest incarnation of opticalstorage to hit the market. While a dual-layeredDVD can store about 9.8 gigabytes (GB) ofinformation, this isn’t enough to holdmovies in the high-definition (HD) digitalformat that has become so popular. Blu-raydiscs, which are very similar in size andshape to DVDs, can hold up to 50 GB ofdata. This is enough to hold approximately4.5 hours of high-definition video.

You may occasionally see a PC that stillhas a bay for a floppy disk drive, whichreads and writes to easily transportablefloppy disks that hold a limited amount ofdata. Some computers also feature a Zipdisk drive, which resembles a floppy diskdrive but has a slightly wider opening.Zip disks work just like standard floppiesbut can carry much more data. These stor-age devices are fast becoming legacy tech-nologies and are no longer found on newcomputers.

Flash drives, sometimes referred to asjump drives, USB drives, or thumb drives,

Handout/MCT/NewsCom

Courtesy WesternDigital Corporation

The System Unit

32). The ports on the back of the system unitare usually used for devices that stayattached to the computer at all times (suchas a printer) while ports on the front areused for convenient connection of portabledevices (digital cameras). Serial ports andparallel ports have long been used to connectinput and output devices to the computerbut are fast becoming legacy technology.Traditional serial ports send data one bit (orpiece of data) at a time and are often used toconnect modems (devices used to transmitdata over telecommunications lines) to thecomputer. Sending data one bit at a time is aslow way to communicate. Data sent overserial ports is transferred at a speed of 115kilobits per second (Kbps), or 115,000 bits persecond. A parallel port sends data betweendevices in groups of bits at speeds of 500Kbps and is therefore much faster than a tra-ditional serial port. Parallel ports were oftenused to connect printers to computers, butUSB ports are now vastly more popular.

Universal serial bus (USB) ports are nowthe most popular ports used to connectinput and output devices to the computer.This is mainly because of their ability totransfer data quickly. USB 2.0 ports transferdata at 480 Mbps and are approximately 40times faster than the original USB port. USB

ports can connect a wide variety of periph-erals to the computer, including keyboards,printers, mice, smartphones, and digitalcameras. Because most peripheral devicestoday offer USB connectivity, given twoequal computers, you should consider

B I T S A N D B Y T E SGetting a New Car? Consider One

with Bluetooth!

Many cell phone users have Bluetooth headsets to use their phonehands-free. So why shouldn’t you enjoy the same convenience inyour car? Many manufacturers (such as Toyota, Nissan, and Audi)offer Bluetooth systems as options for their cars. So forget bulky,ugly docking stations for your mobile phone. If your phone andcar are Bluetooth enabled, just hop in and use your phone in thehands-free mode with no wired connections to worry about.Microphones and control panels for the systems are usuallymounted in the dash. And car manufacturers are beefing up thememory for the Bluetooth systems that are in their cars with morememory to hold information such as your mobile phone addressbook or the contents of your PDA. With many states passing lawsprohibiting cell phone use in cars except in a hands-free mode,Bluetooth might be a necessary car option in your future.

STORAGE MEDIUM CAPABILITIES STORAGE CAPACITY

Hard Drive Read and write External: Up to 2 TB (Terabyte)Internal: Up to 750 GB

CD CD-RW

Read-only Read and write

700 MB

DVD DVD+RW

Read-only Read and write

4.7 GB (for single-sided,single-layered DVDs) 9.4 GB (for single-sided,dual-layered DVDs)

Blu-ray (BD) Read and write 27 GB (for single-layer discs)50 GB (for dual-layer discs)

Flash MemoryCards

Read and write 8 GB (or more)

Flash Drive Read and write 12 GB (or more)

FIGURE 30 Storage Media Capacities

d) Sony Electronics, Inc./NewsCom; e) SanDisk Corporation f) Lexar/USB drive

Looking at Computers: Understanding the Parts

purchasing the computer with the greaternumber of USB ports.

Which ports help me connect withother computers and theInternet? Another set of ports on yourcomputer helps you communicate with othercomputers. Called connectivity ports, theseports give you access to networks and theInternet and enable your computer to func-tion as a fax machine. To find connectivityports, look for a port that resembles a stan-dard phone jack but is slightly larger. Thisport is called an Ethernet port. This porttransfers data at speeds up to 1000 Mbps.You use it to connect your computer to aDSL/cable modem or a network. Many com-puters still feature a second connectivity portthat will accept a standard phoneline connec-tor. This jack is the modem port. It uses a tra-ditional telephone signal to connect to theInternet over a standard phone line.

Besides ports, what else can helpme make connections? Many comput-ers (especially notebooks) and other devices,such as smartphones, printers, and key-boards, feature built-in wireless connectivitydevices. If your computer is equipped withtechnologies such as Bluetooth or wirelessEthernet (a way of transmitting Internet ornetwork connection data), you can connectto other devices that have these technologieswithout using traditional ports and cables.

What are the fastest ports avail-able? Interfaces such as FireWire 400 (orIEEE 1394) and the latest FireWire 800 arethe fastest ports available. The FireWire 400interface moves data at 400 Mbps, while thenewer FireWire 800 doubles the rate to 800Mbps. Devices such as external hard drives,digital video cameras, MP3 players, and dig-ital media players all benefit from the speedydata transfer of FireWire.

Parallel port

Monitor port

S-video

DVI port

USB ports

FireWire port

Modem portor RJ-11 port

Ethernet portSpeaker port

Microphone port

FIGURE 32

Notebooks havemany of the portsyou find on desktopcomputers.

Serial ports

Audio ports

Parallel port

USB ports

FireWire ports

Modem port

Video ports

Ethernet andUSB ports

FIGURE 31

The back of your computer probably has many or all of these ports, although theymay not be in the same places. There are several different ports because manydevices exchange data with the computer in various ways. Color coding helpsidentify the correct device to connect to each port.

Courtesy ofInternationalBusiness MachinesCorporation.Unauthorized use not permitted.

The System Unit

What are the other ports on theback? Other ports on the back of the com-puter include the audio and video ports. TheVGA (video graphics array) monitor port isthe standard port to which monitors (bothCRT and LCD) connect. Audio ports or jacksare where you connect headphones, micro-phones, and speakers to the computer.

INSIDE THE SYSTEM UNIT

What’s inside the system unit? Figure33 shows the layout common to many systemunits. As you can see, the power supply ishoused inside the system unit to regulate thewall voltage to the voltages required by com-puter chips. Inside the system unit, you’llalso find many printed circuit boards, whichare flat, thin boards made of material thatwon’t conduct electricity. On top of this mate-rial, thin copper lines are traced, allowingdesigners to connect a set of computer chips.

The various circuit boards have specificfunctions that augment the computer’s basicfunctions. Some provide connections to otherdevices, so these are usually referred to asexpansion cards (or adapter cards). Typicalexpansion cards found in the system unit arethe sound card and video card. A sound card

provides a connection for the speakers andmicrophone, while a video card provides aconnection for the monitor. Other expansioncards provide a means for network andInternet connections such as the modemcard, which provides the computer with aconnection to the Internet via a traditionalphone line, and a network interface card(NIC), which enables your computer to con-nect with other computers or to a cablemodem to facilitate a high-speed Internetconnection.

On the bottom or side of the system unit,you’ll find the largest printed circuit board,called the motherboard. The motherboard isnamed such because all of the other boards(video cards, sound cards, and so on) connectto it to receive power and to communicate—therefore, it’s the “mother” of all boards.

Power supply

Motherboard

Hard disk drive

Empty drive bay

Floppy drive

Productivityports

DVD drive

CD drive

Adapter cards (such as

sound card)

FIGURE 33

Inside the System Unit

SOUND BYTEPort Tour: How Do I Hook It Up?

In this Sound Byte, you’ll take a tour of both a desktop system and anotebook system to compare the number and variety of availableports. You’ll also learn about the different types of ports and comparetheir speed and expandability.

Courtesy ofInternational BusinessMachines Corporation.Unauthorized use notpermitted.

Looking at Computers: Understanding the Parts

What’s on the motherboard? Themotherboard contains the set of chips thatpowers the system, including the centralprocessing unit (CPU). The motherboardalso houses the chips that provide theshort-term memory for the computer aswell as a set of slots available for expan-sion cards (see Figure 34). Many low-endcomputer models have motherboards withvideo and sound capabilities integratedinto the motherboard. High-end modelsstill use expansion cards to provide videoand sound capabilities.

What is the CPU? The central pro-cessing unit (CPU, or processor) is thelargest and most important chip in thecomputer. It is sometimes referred to as the“brains” of the computer because it con-trols all the functions performed by thecomputer’s other components andprocesses all the commands issued to it bysoftware instructions. Modern CPUs canperform three billion tasks a second with-out error, making them extremely powerfulcomponents.

What exactly is RAM? Because theCPU processes data so rapidly, there needsto be a way to store data and commandsnearby so that they can be fed to the CPUvery quickly. Random access memory(RAM) is that storage space. If you look at

Memory modules(RAM)

CPU

Expansion slot

Expansion cards

FIGURE 34

A motherboard con-tains the CPU, thememory (RAM) cards,and slots available forexpansion cards.

a motherboard, you’ll see RAM as a seriesof small cards (called memory cards ormemory modules) plugged into slots onthe motherboard. The CPU can request thecontents of RAM, which can be located,opened, and delivered to the CPU for pro-cessing in a few billionths of a second (ornanoseconds).

Sometimes RAM is referred to as pri-mary storage, but it should not be con-fused with other types of permanent stor-age devices. Because all the contents ofRAM are erased when you turn off thecomputer, RAM is the temporaryorvolatile storage location for the computer.To save data permanently, you need tosave it to the hard drive or to another per-manent storage device such as a floppydisk, CD, or flash drive.

SOUND BYTEVirtual Computer Tour

In this Sound Byte, you’ll take a video tour of the inside of a sys-tem unit. From opening the cover to locating the power supply,CPU, and memory, you’ll become more familiar with what’s insideyour computer.

Setting It All Up

Does the system unit contain anyother kinds of memory besidesRAM? In addition to RAM, the mother-board also contains a form of memorycalled read-only memory (ROM). ROMholds all the instructions the computerneeds to start up. Unlike data stored inRAM, which is volatile storage, the instruc-tions stored in ROM are permanent, makingROM a nonvolatile storage location. As isthe case with the hard disk drive, thismeans it does not get erased when thepower is turned off.

Setting It All UpIt’s important that you understand notonly your computer’s components andhow they work together, but also how toset up these components safely. Merriam-Webster’s Dictionary defines ergonomics as“an applied science concerned withdesigning and arranging things peopleuse so that the people and things interactmost efficiently and safely.” In terms ofcomputing, ergonomics refers to how youset up your computer and other equip-ment to minimize your risk of injury ordiscomfort.

Why is ergonomics important?Workplace injuries related to musculo-skeletal disorders occur frequently in theUnited States. Approximately 375,500

workers experienced such disorders in2005 (the latest year for which data isavailable), and these disorders requiredan average of 9 days off from work asreported by the United States Departmentof Labor Bureau of Labor Statistics(www.bls.gov/news.release/osh2.toc.htm).This resulted in businesses incurring bil-lions of dollars of direct costs (sick pay,medical costs) and even more indirectcosts (lost productivity, overtime, valueof employee time involved in the acci-dent, cost of recordkeeping and investiga-tion, etc.). Avoiding workplace injuries isnot only good for employees, but it isvery financially favorable for businesses,too.

How can I avoid injuries when I’mworking at my computer? The fol-lowing are some guidelines that can helpyou avoid discomfort, eyestrain, orinjuries while you’re working at yourcomputer:

• Position your monitor correctly.Studies suggest it’s best to place yourmonitor at least 25 inches from youreyes. You may need to decrease thescreen resolution to make text andimages more readable at that distance.Also, experts recommend the monitorbe positioned either at eye level or sothat it is at an angle 15 to 20 degreesbelow your line of sight.

B I T S A N D B Y T E SOpening Your System Unit

Many people use a computer for years without everneeding to open their system unit. But there are tworeasons you might want or need to do so: to replace adefective expansion card or device or to upgrade yourcomputer. If your hard drive or CD-ROM drive fails,with a bit of guidance, you can open the systemunit yourself and replace the drive yourself. Addingmore memory or adding a DVD-RW drive areupgrade procedures that you can do safely at home.However, it’s important that you follow the device’sspecific installation instructions. These instructionswill detail any safety procedures you’ll need toobserve, such as unplugging the computer andgrounding yourself to avoid static electricity

discharge, which can damage internal components. It’salso important to check with the manufacturer of yoursystem to see if opening the case will void the system’swarranty.

Does my computer need anything else to func-tion? If you have other digital devices in your house(such as computers, a TiVo, or gaming consoles) thatneed to be connected to the Internet, you probablyneed to set up a home computer network. A networkis a combination of hardware and software that facili-tates the sharing of information between computingdevices. Therefore, your computer may require addi-tional networking hardware such as a router andcables.

Looking at Computers: Understanding the Parts

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SOUND BYTEHealthy Computing

In this Sound Byte, you’ll see how to set up your workspace in anergonomically correct way. You’ll learn the proper location of themonitor, keyboard, and mouse, as well as ergonomic features to lookfor when choosing the most appropriate chair.

FIGURE 36

(a) Ergonomic keyboards that curve and con-tain built-in wrist rests help you maintain properhand position to minimize strain on your wrists.(b) Ergonomic pointing devices replace conven-tional mice to reduce stress on the wrist andfingers.

Arms that are heightadjustable help you

position your wrists toavoid repetitive strain

injuries

Levers that you caneasily reach while

seated to adjust chairheight, angle of seatcushion, and angle of

chair back

Contoured back withlumbar support that is

height adjustable

FIGURE 35

Look for these key features when selectingan ergonomic chair.

• Purchase an adjustable chair (seeFigure 35). Adjust the height of yourchair so that your feet touch the floor.(You may need to use a footrest to getthe right position.) Back support needsto be adjustable so that you can posi-tion it to support your lumbar (lowerback) region. You should also be ableto move the seat or adjust the back sothat you can sit without exerting pres-sure on your knees. If your chair doesn’t adjust, placing a pillow behindyour back can provide the same support.

• Assume a proper position while typ-ing. A repetitive strain injury (RSI) is apainful condition caused by repetitiveor awkward movements of a part ofthe body. Improperly positioned key-boards are one of the leading causes ofRSIs in computer users. Your wristsshould be flat (unbent) with respect tothe keyboard and your forearms paral-lel to the floor. You can either adjustthe height of your chair or install aheight-adjustable keyboard tray toensure a proper position. Speciallydesigned ergonomic keyboards likethe ones shown in Figure 36 can helpyou achieve the proper position ofyour wrists.

• Take breaks from computer tasks.Remaining in the same position forlong periods of time increases stress onyour body. Shift your position in yourchair and stretch your hands and fin-gers periodically. Likewise, staring atthe screen for long periods of time canlead to eyestrain, so rest your eyes byperiodically taking them off the screenand focusing them on an object at least20 feet away.

• Ensure the lighting is adequate. Assuringproper lighting in your work area is a goodway to minimize eyestrain. To do so,

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Setting It All Up

Top of monitorat or beloweye level

Fully adjustablechair allows youto control heightof chair, seatposition, andangle of back

Lumbarsupport

Adjustablemonitor

Footrestif needed

Adjustable-height keyboard tray and a wrist rest allow you to keep your wrists straight while typing

FIGURE 37

Achieving comfort and a proper typing position is the way to avoid repetitive strain injuries and other aches andpains while working at a computer. To achieve this, obtain equipment that boasts as many adjustments as possi-ble. Every person is a different shape and size, requiring each workspace to be individually tailored. In addition,look for ergonomically designed peripheral devices such as keyboards, wrist rests, and antiglare screens tofacilitate a safe working environment.

eliminate any sources of direct glare(light shining directly into your eyes) orreflected glare (light shining off the com-puter screen) and ensure there is enoughlight to read comfortably. If you stillcan’t eliminate glare from your com-puter screen, you can purchase anantiglare screen to place over your mon-

itor. Look for ones that are polarized orhave a purplish optical coating for thegreatest relief.

Figure 37 illustrates how you shouldarrange your monitor, chair, body, and key-board to avoid injury or discomfort whileyou’re working on your computer.

Looking at Computers: Understanding the Parts

T R E N D S I N I TEmerging Technologies: Tomorrow’s Display—You Can Take It with You!

Today, LCD monitors dominate the desktop PC andnotebook markets. Lighter and less bulky than previousmonitors, they can be easily moved and take up lessspace on a desk. LCD technology has improved signifi-cantly over the past three years, and now monitors aresporting increased viewing angles, higher resolutions,and faster pixel response time, which makes full-motionvideo (critical for gamers) appear very smooth.

Despite these advances, LCDs can still be improvedand are expected to continue to be the predominant dis-play device in the next few years. Here are a few tech-nologies that sources like PC Magazine feel will takeLCD displays to the next level.

Flexible ScreensThe most promising displays currently under develop-ment are organic light-emitting displays (OLEDs).

These displays, currently used in digital cameras, useorganic compounds that produce light when exposed toan electric current. OLEDs tend to use less power thanother flat-screen technologies, making them ideal forportable battery-operated devices. However, mostresearch is being geared toward flexible OLEDs(FOLEDs). Unlike LCDs and CRTs, which use rigid sur-faces such as glass, FOLED screens would be designedon lightweight, inexpensive, flexible material such astransparent plastics or metal foils. As shown in Figure38, the computer screen of the future might roll up intoan easily transported cylinder the size of a pen!

FOLEDs would allow advertising to progress to anew dimension. Screens could be hung where postersare hung now (such as on billboards). And wirelesstransmission of data to these screens would allowadvertisers to display easily updatable full-motion

FIGURE 38

With FOLED technology, you’ll be able to unroll a computer screen wherever you need it from a container the size of a pen. The prototypeshown is currently being developed by Universal Display Corporation (www.universaldisplay.com) and should be available within a fewyears.

Universal Display Corporation

Setting It All Up

images. Combining transparency and flexibility wouldalso allow these displays to be mounted on windshieldsor eyeglasses.

Another promising new technology is transparentthin-film transistors (TFTs). These transistors contain amixture of zinc and tin oxides, instead of the tradi-tional silicon, and the coolest thing about them is thatthey are transparent, flexible, and extremely heat resis-tant! Imagine a computer chip crammed with transis-tors but totally clear. Because they are clear, TFTs couldeventually find their way into heads-up displays oncar windshields or in stores as advertising on plate-glass windows.

There are some obstacles to be overcome beforethese types of screens will be widely available. InOLEDs and FOLEDs, the compounds that create bluehues age faster than the ones that produce reds andgreens. This makes it difficult to maintain balancedcolors over time. And the compounds used to form theOLEDs can be contaminated by exposure to watervapor or oxygen. The TFT technology is so new that itwill probably be at least a decade before this technol-ogy appears in the consumer market. However,because of ongoing research, you can be sure that inyour lifetime flexible displays will be popping upeverywhere.

Wearable ScreensWho needs a screen when you can just wear one?With the rise of the iPod and other portable devicesthat play digital video, users are demanding largerviewing areas. Although a larger screen is oftenincompatible with the main design features ofportable devices (lightweight and long battery life),wearable virtual displays offer a solution. Personalmedia viewer displays such as the myvu, shown inFigure 39, are available now (www.myvu.com).Eventually, when the technology advances suffi-ciently, you might purchase conventional eyeglasseswith displays built right in. Wearable displays mighteventually replace heavier screens on notebooks,desktops, and even PDAs.

“Bistable” ScreensYour computer screen constantly changes its imageswhen you are surfing the Internet or playing a game.Because PDA and cell phone screens don’t necessarilychange that often, something called a “bistable” display,

currently used in retail stores for pricing signs, may oneday be used in these devices. A bistable display has theability to retain its image even when the power isturned off. In addition, bistable displays are lighter thanLCD displays and reduce overall power consumption,resulting in longer battery life—research by Motorolaindicates up to 600 times longer life! As the market forportable devices, such as smartphones, continues toexplode, you can expect to see bistable technologiesemerging in mobile computer screens.

FIGURE 39

A prototype developed by MicroOptical Corporation features amicrodisplay embedded in a pair of glasses. To users, it appears asthough the display is projected right in front of them. Within a fewyears, you’ll be able to buy a microdisplay when you buy glasses.

Myvu Corporation

Looking at Computers: Understanding the Parts

Summary1. What exactly is a computer, and

what are its four main functions?Computers are devices that process data.They help organize, sort, and categorizedata to turn it into information. The com-puter’s four major functions are (1) togather data (or allow users to input data);(2) to process that data (perform calcula-tions or some other manipulation of thedata); (3) to output data or information(display information in a form suitable forthe user); and (4) to store data and infor-mation for later use.

2. What is the difference between dataand information?Data is a representation of a fact or idea.The number 3 and the words televisions orSony are pieces of data. Information is datathat has been organized or presented in ameaningful fashion. An inventory list thatindicates that “3 Sony televisions” are instock is processed information. It allows aretail clerk to answer a customer queryabout the availability of merchandise.Information is more powerful than rawdata.

3. What are bits and bytes, and howare they measured?To process data into information, comput-ers need to work in a language they under-stand. This language, called binary lan-guage, consists of two numbers: 0 and 1.Each 0 and 1 is a binary digit, or bit. Eightbits create one byte. In computers, each let-ter of the alphabet, each number, and eachspecial character consists of a unique com-bination of eight bits (one byte), or a stringof eight 0s and 1s. For describing largeamounts of storage capacity, the termskilobyte (approximately 1,000 bytes),megabyte (approximately one millionbytes), and gigabyte (approximately one bil-lion bytes) are used.

4. What devices do you use to get datainto the computer?An input device enables you to enter data(text, images, and sounds) and instructions(user responses and commands) into acomputer. You use keyboards to enter

typed data and commands, whereas youuse the mouse to enter user responses andcommands. Keyboards are distinguishedby the layout of the keys as well as the spe-cial keys found on the keyboard. The mostcommon keyboard is the QWERTY key-board. The Dvorak keyboard is a leader inalternative keyboards. The Dvorak key-board puts the most commonly used lettersin the English language on “home keys,”which are the keys in the middle row of thekeyboard. Keyboards that feature keys thatcan be rearranged and reprogrammed arepopular with gamers.Notebook keyboards are more compactand have fewer keys than standard key-boards. Still, many notebook keys havealternate functions so that you can get thesame capabilities from the limited numberof keys as you do from the special keys onstandard keyboards. PDAs use a stylusinstead of a keyboard.Most computers come with wired opticalmice, but other options include trackballmice and wireless mice. An optical mouseuses an internal sensor or laser to controlthe mouse’s movement. In a trackballmouse, a rollerball sits on top or on theside of the mouse so that you can move theball with your fingers. Wireless mice usebatteries and send data to the computer viaradio or light waves.Notebooks incorporate the mouse into thekeyboard area. Notebook mice includetrackpoints and touchpads. Microphonesare the devices used to input sounds,whereas scanners and digital camerasinput nondigital text and images.

5. What devices do you use to getinformation out of the computer?Output devices enable you to sendprocessed data out of your computer. Thiscan take the form of text, pictures, sounds,and video. Monitors display soft copies oftext, graphics, and video, while printerscreate hard copies of text and graphics.LCDs are the most popular type of moni-tor. Also called flat panel monitors, theytake up less space and are lighter and moreenergy efficient than older CRT monitors(which look like TV sets), making themperfect for portable computers. Today’s

LCD monitors support high-screen resolu-tions, have wider viewing angles and fea-ture fast response pixel time so full-motionvideo appears smooth.There are two primary categories of print-ers: impact and nonimpact. Impact print-ers have hammer-like keys that strike thepaper through an inked ribbon.Nonimpact printers spray ink or use laserbeams to transfer marks on the paper. Themost common nonimpact printers areinkjet printers and laser printers. Specialtyprinters are also available. These includemultifunction printers, plotters, and ther-mal printers. When choosing a printer,you should be aware of factors such asspeed, resolution, color output, memory,and cost. Speakers are the output devices for sound.Most computers include speakers.However, you may want to upgrade to amore sophisticated speaker system, suchas one that includes subwoofers and sur-round-sound.

6. What’s on the front of your systemunit?The system unit is a box that contains thecentral electronic components of a com-puter. On the front of the system unit,you’ll find the power source as well asaccess to the storage devices in your com-puter. Most PCs include one or two baysfor storage devices such as CD drives andDVD drives. Zip drives and floppy diskdrives are becoming legacy technologiesand are not found on new computers. Mostcomputers include access to USB and otherports on the front panel, and some manu-facturers now also include slots on thefront of the system unit into which you caninsert portable flash memory cards such asMemory Sticks and CompactFlash cards.

7. What’s on the back of your systemunit?On the back of the system unit or note-book, you’ll find a wide variety of portsthat allow you to hook up peripheraldevices (such as your monitor and key-board) to your system. The most commonports found on the back of the system unit

are USB and connectivity (networking)ports. Serial ports and parallel ports arelegacy technology now. The most popularport for connecting devices is the USB port.USB 2.0 ports transfer data at 480 Mbps,which is much faster than the parallel andserial ports they displaced. Firewire 400and 800 ports provide even faster datatransfer at approximately 400 and 800Mbps, respectively.Connectivity ports give you access to net-works and the Internet and enable yourcomputer to function as a fax machine.Connectivity ports include Ethernet portsand modem ports.

8. What’s inside your system unit?The system unit contains the main elec-tronic components of the computer. Themotherboard, the main circuit board ofthe system, contains a computer’s centralprocessing unit (CPU), which coordinatesthe functions of all other devices on thecomputer. RAM, the computer’s volatilememory, is also located on the mother-board. RAM is where all the data andinstructions are held while the computeris running. ROM, a permanent type ofmemory, is responsible for housinginstructions to help start up a computer.The hard drive (the permanent storagelocation) and other storage devices (CDand DVD drives) are also located insidethe system unit, as are expansion cards(such as sound, video, modem, and net-work interface cards) that help a com-puter perform special functions.

9. How do you set up your computer toavoid strain and injury?Ergonomics refers to how you arrangeyour computer and equipment to minimizeyour risk of injury or discomfort. Thisincludes positioning your monitor cor-rectly, buying an adjustable chair thatensures you have good posture whileusing the computer, assuming a properposition while typing, and making sure thelighting is adequate. Other good practicesinclude taking frequent breaks as well asusing other specially designed equipmentsuch as ergonomic keyboards.

Looking at Computers: Understanding the Parts

Key Termsactive-matrix displayAlt keyapplication softwarebinary digit (bit)binary languageBlu-rayBluetoothbrightnessbytecathode-ray tube (CRT)CD-ROM driveCD-RW drivecentral processing unit (CPU,

or processor)cold bootcomputerconnectivity portcontrast ratioControl key (Ctrl key)cursorcursor control keysdatadata projectordrive bayDVD driveDVD-RW driveDvorak keyboardergonomicsEthernet portexpansion card (adapter card)external hard driveFireWire 400 (IEEE 1394)FireWire 800flash driveflash memory cardflat-panel monitorfloppy disk drivefunction keysgaming keyboardgigabyte (GB)hard disk drive (hard drive)hardwarehibernationimpact printerinformationinkjet printerinput devicekeyboardkilobyte (KB)laser printerlegacy technologyliquid crystal display (LCD)magnetically shielded microphonemegabyte (MB)microphone (mic)

modem cardmodem portmonitor (display screen)motherboardmousemultifunction printernetwork interface card (NIC)nonimpact printernonvolatile storagenotebook computernumeric keypadomnidirectional microphoneoperating system (OS)52optical mouseoutput deviceparallel portpassive-matrix displayperipheral devicepixelplotterportpower supplyprinterprocessingQWERTY keyboardrandom access memory (RAM)read-only memory (ROM)resolutionresponse timeserial portSleep modesoftwaresound cardspeakerspeech-recognition systemstylussubwoofersurround-sound capabilitysystem softwaresystem unitthermal printertoggle keytouch-screen monitortouchpadtrackball mousetrackpoint deviceunidirectional microphoneuniversal serial bus (USB) portUSB 2.0video cardviewing anglevolatile storagewarm bootwebcamWindows keyZip disk drive

Buzz WordsWord Bank

• CPU• CRT• Dvorak• ergonomics• FireWire• inkjet printer

• laser printer• LCD• microphone• monitor• mouse• optical

• QWERTY• RAM• ROM• speakers• system unit• USB

Instructions: Fill in the blanks using the words from the Word Bank above.

Austin had been getting a sore back and stiff arms when he sat at his desk, so heredesigned the (1) __________ of his computer setup. He placed the (2) __________ so that itwas 25 inches from his eyes, and he bought an adjustable chair. He also decided to improvehis equipment in other ways. His (3) __________ was old, so he replaced it with a(n) (4) __________ mouse that didn’t need a mousepad. To plug in the mouse, he used a(n) (5) __________ port on the back of his (6) __________ . He considered buying an alternativekeyboard to replace the (7) __________ keyboard he got with his computer, but he didn’tknow much about alternative keyboards like the (8) __________ keyboard, so he decided towait.

Because he often printed flyers for his band, Austin decided to buy a printer that couldprint text-based pages quickly. Although he decided to keep his (9) __________ to print pho-tos, he decided to buy a new (10) __________ to print his flyers faster. While looking atprinters, Austin also noticed (11) __________ monitors that would take up less space on hisdesk than the (12) __________ monitor he had. Unfortunately, he couldn’t afford to buy anew monitor. However, he decided he could afford new (13) __________ because the onesthat came with his computer didn’t have subwoofers. He also bought a professional (14) __________ a while back for use with his band. Finally, knowing his system could usemore memory, Austin checked out prices for additional (15) __________.

Becoming Computer LiterateYour parents live a day’s drive from your school and have just called asking you for help insetting up their new computer.

Instructions: Because you can’t help them in person, prepare a setup guide for your par-ents as either a Word document or slide presentation. Your setup guide should have all thecomponents of a computer system illustrated and defined. In addition, you should describewith illustrations and words the various ports your parents will need to use to attach vari-ous peripheral devices to the system unit. You may use the Internet for information, devicepictures, and illustrations, but remember to credit all sources at the end of your guide.

Looking at Computers: Understanding the Parts

Self-Test

1. Which devices below are consideredinput devices?a. Keyboard and mouseb. Scanner and printerc. Hard drive and speakersd. Microphone and CD-ROM drive

2. Which of the following is NOT oneof the four major functions of a computer?a. Outputb. Storagec. Processingd. Calculation

3. Which of the following is NOT anoutput device?a. Printerb. Monitorc. Hard drived. Speakers

4. The resolution of a monitor is gov-erned by thea. size of the screen.b. cost of the monitor.c. number of pixels on the screen.d. contrast of the pixels on the screen.

5. All of the following are important toconsider when buying an LCD moni-tor EXCEPTa. brightness.b. pixel swap rate.c. viewing angle.d. resolution.

6. Restarting the system after it hasbeen completed powered off is calleda. a warm boot.b. a standby start.

c. hibernation.d. a cold boot.

7. An Ethernet port is used for connect-ing your computer toa. a network.b. a printer.c. a monitor.d. a digital camera.

8. Which of the following devices isconsidered the “brains” of the com-puter?a. Read–only memoryb. Central processing unitc. Random access memoryd. Motherboard

9. Which of the following statementsabout hard disks is TRUE?a. Hard disks are always installed

inside the system unit of a com-puter.

b. Hard disks are consideredvolatile storage devices.

c. With the rise of flash drives, harddisks are becoming legacy tech-nology.

d. Hard disks are considered non-volatile storage devices.

10. Why is an ergonomically correct setupfor your computer system essential?a. Reduces eyestrainb. Prevents repetitive strain injuriesc. Complies with federal lawsd. a & be. b & cf. a & cg. All of the aboveh. None of the above

TRUE/FALSE____ 1. The terms data and information can be used interchangeably.

____ 2. ROM is volatile storage that is located on the motherboard.

____ 3. The CPU is located on the expansion board.

____ 4. USB ports are the most popular port used for connecting peripherals to a computer.

____ 5. Keeping your wrists flat while typing at a computer will help prevent repetitivestrain injuries.

MULTIPLE CHOICE

Instructions: Answer the multiple-choice and true/false questions below for more prac-tice with key terms and concepts from this chapter.

Making the Transition to...Next Semester1. Choosing the Best Keyboard

Once you become more familiar with software products such as Microsoft Office, youmay want to migrate to a customized keyboard design. Although keyboards have simi-lar setups, some keyboards provide special keys and buttons to support different users.For example, some keyboards are designed specifically for multimedia use, Internetuse, and gaming use use. Which one is best for you?a. Examine the various keyboard setups at the Microsoft Web site (www.microsoft.com/

hardware/mouseandkeyboard/default.mspx). Which keyboard would best suit yourneeds and why? What features would be most useful to you? How would you eval-uate the additional costs versus the benefits?

b. What advantages would a wireless keyboard give you? How much do wireless key-boards cost? What price would you be willing to pay to go wireless?

c. When would you need a keyboard for your portable computing devices (such as asmartphone or PDA)? What is the current price for a portable folding keyboard?Would the virtual keyboard described in the chapter be a better choice for you?Explain your answers.

2. Choosing the Best Mouse

On the Web, research the different kinds of mice available and list their special features,functions, and costs. Of these mice, which do you think would be most useful to you? Why?

3. Pricing Computer Upgrades

On the Internet, investigate the following:a. How much would it cost to add a Blu-ray drive to your computer? Does your sys-

tem have an extra drive bay to install a Blu-ray drive?b. How much would it cost to buy new 21-inch LCD monitors? What kind of monitor

would be best to play games, view DVDs, or play back recorded TV shows?c. How much do various computer speaker systems cost? What speakers would be

best to listen to CDs? What speakers would be useful when playing games?d. Do you know whether your current sound card and video card support the new

devices? How could you find this out?

4. Exploring Scanners

One input device you did not explore in the text is a scanner. Conduct the followingresearch on the Web to find out about scanners:a. What are the different kinds of scanners on the market?b. What qualities do good scanners have?c. How much do scanners cost?d. Create a table comparing all the specifications listed earlier for several different

scanners. Highlight the scanner you would be most interested in purchasing.

5. Keyboard Shortcuts

Knowing and using keyboard shortcuts can save you a lot of time while you are doingyour work or homework. Research and compile a list of keyboard shortcuts for the fol-lowing software:a. Microsoft Windows Vistab. Apple OS Xc. Microsoft Word 2007

Looking at Computers: Understanding the Parts

Making the Transition to...the Workplace1. Desktop Versus Notebook

There are two main types of computers in the workplace: desktop computers with sep-arate system units and monitors, and notebook computers that are portable and havethe monitors, keyboards and the system unit all contained within a single case. If youwere being interviewed for a job, what types of questions would you need to ask yourprospective boss about the job to determine whether you needed a desktop or a note-book computer?

2. What System Will You Use?

When you arrive at a new position for a company, you’ll most likely be provided with acomputer. Based on the career you are in now or are planning to pursue, answer thefollowing questions:a. What kind of computer system would you most like to use (PC, Mac, desktop con-

figuration, notebook, PDA, and so on)?b. If you were required to use a type of computer you had never used before (say a

Mac instead of a PC), how would you go about learning to use the new computer?c. What kind of keyboard, mouse, monitor, and printer would you like to have?d. Would you need any additional input or output devices to perform your job?

3. What Hardware Will You Use?

What types of computer hardware would make your work life more efficient? Whatadjustments would you need to make on your current system to accommodate thosehardware devices? (For example, does your computer have the right kind of port orenough ports to support additional hardware devices?)

4. Choosing the Best Printer

You are looking for a new printer for your home business. You have always had an inkjetprinter, but now that the costs for color laser printers are dropping, you’re consideringbuying a color laser printer. However, you’re still unsure because they’re more expensivethan inkjet printers, although you’ve heard that there is an overall cost savings with laserprinters when the cost of toner/ink and paper is taken into consideration.a. Using the Internet, investigate the merits of different inkjet and color laser printers.

Narrow in on one printer in each category and note the initial cost of each.b. Research the cost of ink/toner for each printer. Calculate the cost of ink/toner sup-

plies for each printer, assuming you will print 5,000 color pages per year. Howmuch will it cost per page of printing, not including the initial cost of the printeritself?

c. Investigate the multipurpose printers that also have faxing, scanning, and copyingcapabilities. How much more expensive are they than a traditional inkjet or laserprinter? Are there any drawbacks to these multipurpose machines? Do they performeach function as well as their stand-alone counterparts? Can you print in color onthese machines?

d. Based on your research, which printer would be the most economical?

5. Office Ergonomics

Your boss has designated you as the “ergonomics coordinator” for the department. Shehas asked you to design a flyer to be posted around the office informing your cowork-ers of the proper computer setup as well as the potential risks if such precautions areavoided. Create an ergonomics flyer, making sure it fits on an 8.5 x 11 piece of paper.

Critical Thinking QuestionsInstructions: Albert Einstein used “Gedanken experiments,” or critical thinking ques-tions, to develop his theory of relativity. Some ideas are best understood by experimentingwith them in our own minds. The following critical thinking questions are designed todemand your full attention but require only a comfortable chair—no technology.

1. Keyboard of the Future

What do you think the keyboard of the future will look like? What capabilities will ithave that keyboards currently don’t have? Will it have ports? cables? special communi-cations capabilities?

2. Mouse of the Future

What do you think the mouse (or other pointing device) of the future will look like?What sorts of improvements on the traditional mouse can you imagine? Do you thinkthere will ever be a day when we won’t need mice and keyboards to use our computers?

3. Storage Devices of the Future

How do you think storage devices will change in the future? Will increased storagecapacity and decreased size affect the ways in which we use computers? Will we needstorage devices in the future, or will we access all of our data via the Internet?

4. Computers Decreasing Productivity?

Can you think of any situations in which computers actually decrease productivity?Why? Should we always expect computers to increase our productivity? What do youthink the impact of using computers would be:a. in a third-grade classroom?b. in a manager’s office for a large chain supermarket?c. for a retired couple who purchases their first computer?

5. “Smart” Homes

The Smart Medical Home project of the University of Rochester’s Center for FutureHealth is researching how to use technology to monitor many aspects of your health. TheSmart Medical Home is the creation of a cross-disciplinary group of scientists and engi-neers from the college, the Medical Center, and the university’s Center for Future Health.This particular “smart home” includes a sophisticated computer system that helps keeptrack of items such as eyeglasses or keys, and the kitchen is equipped with a new kind ofpackaging to signal the presence of dangerous bacteria in food. Spaces between ordinarywalls are stuffed with gadgetry, including banks of powerful computers.a. What abilities should a smart home have to safeguard and improve the quality of

your life?b. Could there be potential hazards of a smart home?

6. Toy or Computer?

When do you think a toy becomes a computer? The Microsoft Xbox 360 has a hard diskdrive, a processor with three cores, internal RAM, and wireless capability. Apple iPodsalso have hard disk drives (or flash memory and a processor). Are these devices com-puters or toys? What capabilities do you think the next generation gaming consolesand iPods should have?

Looking at Computers: Understanding the Parts

Team Time PCs vs. Apples: Which Is Best?

Problem:

There are two major classes of computer systems in the marketplace today: PCs and Applecomputers. Many people have chosen one camp with an almost religious fervor. In thisexercise, each team will explore the trade-offs between a PC and an Apple computer anddefend their allegiance to one system or the other.

Task:

Split your class into two teams:

Team A is a group of PC diehards. They believe these computers perform as well asApple systems and cost less, providing better value.

Team B is a group of hard-working, Apple-loving software developers. They believe thereare no systems as user-friendly and reliable as those made by Apple.

Look at the following list of settings for computer labs. Each team should decide why theirparticular system would be the best choice in each of these settings.

1. An elementary school considering incorporating more technology into the classroom

2. A small accounting firm expanding into new offices

3. A video production company considering producing digital video

4. A computer system for a home office for an aspiring author

Process:

1. Form the two teams. Think about what your goals are and what information andresources you need to tackle this project.

2. Research and then discuss the components of each system you are recommending. Areany components better suited for each particular need? Consider all the input, output,processing, and storage devices. Are any special devices or peripherals required?

3. Write a summary position paper. For each of the four settings, support your systemrecommendation for

Team A A PC computer system

Team B An Apple system

Conclusion:

There are a number of competing designs for computer systems. Being aware of the optionsin the marketplace and knowing how to analyze the trade-offs in different designs allowsyou to become a better consumer as well as a better computer user.

MultimediaIn addition to the review materials presented here, you’ll find more materials featured withthe book’s multimedia, including the Technology in Action Student Resource CD and theCompanion Web site (www. prenhall.com/techinaction), which will help reinforce yourunderstanding of the chapter content. These materials include the following:

ACTIVE HELPDESKIn Active Helpdesk calls, you’ll assume the role of Helpdesk operator, taking

calls about the concepts you’ve learned in this chapter. You’ll apply what you’velearned and receive feedback from a supervisor to review and reinforce those con-

cepts. The Active Helpdesk calls for this chapter are listed below and can be found on yourStudent Resource CD:

• Understanding Bits and Bytes• Using Input Devices• Using Output Devices

SOUND BYTESSound Bytes are dynamic multimedia tutorials that help demystify even themost complex topics. You’ll view video clips and animations that illustrate com-

puter concepts, and then apply what you’ve learned by reviewing with the SoundByte Labs, which include quizzes and activities specifically tailored to each Sound Byte.The Sound Bytes for this chapter are listed below and can be found on your StudentResource CD:

• Port Tour: How Do I Hook It Up?• Virtual Computer Tour• Healthy Computing

COMPANION WEB SITEThe Technology in Action Companion Web Site includes a variety of additional

materials to help you review and learn more about the topics in this chapter. Theresources available at www.prenhall.com/techinaction include:

• Online Study Guide. Each chapter features an online true/false and multiple-choicequiz. You can take these quizzes, automatically check the results, and e-mail the resultsto your instructor.

• Web Research Projects. Each chapter features a number of Web research projects thatask you to search the Web for information on computer-related careers, milestones incomputer history, important people and companies, emerging technologies, and theapplications and implications of different technologies.