MIKE MEYERS PRESENTS PRESENTS:: Computer Literacy Your Ticket to IC3 Certification SCOTT JERNIGAN ELKS Learning 12929 Gulf Freeway, Suite 105 Houston, Texas 77034 U.S.A. Publisher Dudley Lehmer Editor in Chief Scott Jernigan Technical Editors Martin Acuña, Dudley Lehmer, Mike Meyers Simulation Developers Dudley Lehmer, Janelle Meyers, Michael Smyer Computer Literacy – Your Ticket to IC3 Certification Scott Jernigan ELKS Learning 12929 Gulf Freeway, Suite 105 Houston, Texas 77009 U.S.A. To arrange bulk purchase discounts for sales promotions, premiums, or fund-raisers, please contact ELKS Learning at the address above. Computer Literacy – Your Ticket to IC3 Certification Contributors Martin Acuña Cindy Clayton Cary Dier Tina Ferguson Jane Holcomb Libby Ingrassia Dudley Lehmer Mike Meyers Jessica Stratton Copyright © 2005 by ELKS Learning. All rights reserved. Printed in the United States of America. Except as permitted under the Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of publisher, with the exception that the program listings may be entered, stored, and executed in a computer system, but they may not be reproduced for publication. Peer Reviewers Kris Donnelly-Sasser Jennifer Passman 1234567890 DOC DOC 019876543 Copy Editors Cindy Clayton, Cary Dier Indexer Cindy Clayton Book p/n 1234567890 and CD p/n 1234567890 parts of ISBN 0-9768422-0-3 Composition Donette Reil Illustrator Michael Smyer Cover Design Donette Reil, Kathy Yale This book was composed with Adobe PageMaker and Adobe InDesign Information has been obtained by ELKS Learning from sources believed to be reliable. However, because of the possibility of human or mechanical error by our sources, ELKS Learning, or others, ELKS Learning does not guarantee the accuracy, adequacy, or completeness of any information and is not responsible for any errors or omissions or the results obtained from the use of such information. About the Author Scott Jernigan wields a mighty red pen as Editor in Chief for Total Seminars. With an M.A. in Medieval History, Scott feels as much at home in the musty archives of London as he does in the warm CRT glow of Total Seminars’ Houston headquarters. Scott has edited and contributed to more than a dozen books on computer literacy, hardware, operating systems, networking, and certification, including co-authoring the best-selling All-in-One A+ Certification Exam Guide, 5th edition, and the A+ Guide to Managing and Troubleshooting PCs (both with Mike Meyers). Scott has taught all over the United States, including stints at the United Nations in New York and the FBI Academy in Quantico. He is an A+ and Network+ certified technician, a Microsoft Certified Professional, a Microsoft Office Specialist, and, of course, Certiport Internet and Computing Core Certified. About Mike Meyers Mike Meyers is the best-selling author of numerous books on computer literacy and certifications, including Introduction to PC Hardware and Troubleshooting, and the Allin-One A+ Certification Exam Guide. Mike is considered the industry expert on computer certifications. Acknowledgments Many people helped put this book together, and I could not have done Computer Literacy without them. The folks listed as Contributors put soul and time into writing, editing, and researching. Thank you. Cindy Clayton pushed for this project for months. The addition of the delightful Audrey Clayton added extra gurgles to her outstanding editing and writing on this book. Martin Acuña put the indelible stamp of his personality on the book, from his excellent writing and editing to the fun movie theme. It was great to work with you, my friend. My publisher, Dudley Lehmer, gave me the encouragement to continue and go through the book-birthing pains, knowing the end result would be something worthy for so many people. Jenny Passman gave (and continues to give) fantastic feedback from the trenches, as she taught with this book as I wrote the chapters. A peer reviewer par excellence, Jenny’s critiques and praise made this a much better book. A hearty thanks goes out to the folks at Desktop and Press in Houston. Donette Reil did an outstanding job designing and implementing the layout of the book. Don Carpenter gave us superb advice on the publishing end of things. Michael Smyer once again proved to be a sparkplug in the book-writing process. His photographs give this book life and he proved to be a master of the illustration. He consistently challenges me on technology, which, frankly, keeps me honest. Superb job, Michael! My dear friend Mike Meyers provided a swift kick in the pants when I needed it and proved a worthy companion for many a late-afternoon gaming session to blow off steam. Kathy Yale, Marketing Director for ELKS Learning and Total Seminars, provided endless enthusiasm for this project. Every time I talked with her I came away reinvigorated and ready to tackle the next chapter or challenge. She proved to be invaluable for getting this book from conceptualization to print. My long-time right hand, Cary Dier, came in at the 11th hour to help finish off this book. I indebted to her and very thankful. You’re the best, my friend. A special thanks to Kris Donnelly-Sasser who gave me some great feedback in the early stages of this book. To my superb colleagues at Total Seminars, thanks for your work and support. Janelle Meyers did amazing stuff with the simulations. Roger Conrad and David Dussé back me up to the point that I couldn’t get my job done without them—and they excel in their own jobs too! Finally, to my wife, Katie, and my children, Maggie and Simon: Thank you for being there for me. I love you. Dedication This book is for my daughter, Maggie: your joy for learning inspires me and your laughter makes my heart lighter. I love you and look forward to reading this book with you. About This Book The Right Tools for Today Almost every skilled job today requires employees to use computers, so computer literacy is simply something that every person should possess. You need to know how computers work and how to perform basic tasks with word processing, spreadsheets, presentation software, and Internet browsers. Scott Jernigan’s Computer Literacy puts these skills into students’ hands, creating the foundation they need for success today. Off the Script! sidebars provide interesting and often fun information that relates to the text students are reading, but diverges from the primary topic. Linux on the Inside IBM PC-based Microcomputer Servers The most common microcomputer, as you know from Part 1 of this book, is based on the original IBM x86 architecture. The servers in this family use Intel or AMD processors, sport gigabytes of DDR RAM, and have multiple hard drives to supply safety for your data if one of the drives fails. They’re commonly referred to as personal computers (PCs). You’ll find server PCs in two basic physical shapes: tower and rack-mounted. Towers slip under a desk or hide in a closet somewhere, acting pretty much like a glorified client PC. Rack mount servers live in closets, generally affixed to a rack along side other rack mounted servers (Figure 1.11). Figure 11: Rack mounted server (Photo courtesy of General Technics) Microsoft makes several versions of Windows designed to run on x86 server PCs (Figure 1.12). Each version offers support for multiple client computers, multiple CPUs, and gobs of RAM. The primary differences are in scale: Windows Server 2003 works for small businesses, for example, whereas larger businesses would want to use Windows Server 2003 Enterprise Edition. Figure 12: Windows Server 2003 Apple Microcomputer Servers Apple makes a version of its popular Macintosh hardware and operating system designed specifically for servers, called Xserve (Figure 1.13). Xserve servers use Motorola and IBM G5 CPUs and, like Windows servers, can have multiple processors, gobs of RAM, and tons of hard drive space. Apple Xserve server systems run a server-class version of Mac OS X called, appropriately, OS X Server. Apple Xserve servers support Macintosh, Windows, and Linux clients. Workstations A workstation is a powerful single-user computer that is similar to a personal computer, except that it has a more powerful microprocessor and a higher-quality monitor. It is used for desktop publishing and engineering applications, and on jobs that require high quality graphics more so than extensive computing power. Workstations are considered to be between minicomputers and personal computers. The better personal computers are equal to lower-end workstations, and the better workstations are equal to minicomputers. Just to add a little confusion to your day, you’ll also hear the term workstation used generically to describe a place where people sit and work on computers. Figure 21.13: Apple Xserve G5 (Photo courtesy of Apple) There are many versions of Linux, called distributions or distros, such as Fedora Linux, Mandrake Linux, and SuSE. Different companies create the distros and make their money in documentation and support. Because Linux is free but complicated, most companies that use any version of Linux opt for one of the supported ones. Discovering Rack Mounts Rack mounted servers don’t sit on the floor like a typical server and they come in quite a variety. Surf on over to General Technics’ Web site (www.gtweb.net) and check out their server cases. What’s the difference between a 1U and a 4U? What sort of hardware would you put in the server? What other rack mounted network components can you find? CHAPTER 1: NETWORK BASICS Real World Computer Literacy This book offers students an overview of the current state of computing in the workplace, not just focusing only on exam topics. Students will read about and understand the latest technology and applications. 7 Linux is the odd duck operating system, because you can run it on IBMstyle PCs, Xserve G5 machines, and most mainframes! Linus Torvalds, a programmer from Finland, created the first version of Linux. Have you ever complained that you didn’t like something, such as the dinner that one of your parents made for you, and they said, “Well, why don’t you go make your own dinner?” Well, Linus didn’t like any of the computer operating systems in use, so he made his own. He wrote the computer code for an operating system based on UNIX, posted it on the Internet, and told other programmers that if they could make it better, they were welcome to do so. Tens of thousands of programmers have made improvements, and Linux is one of the largest collaborative projects in the history of the world. Linux can run on just about any computer, plus it’s free, so it has become very popular (Figure 21.14). UNIX Linux can run on PCs and Macs alike. The UNIX family of operating systems grew up in the heyday of mainframe and minicomputers, and continues to thrive on x86-based microcomputers. Dozens of versions of UNIX run on server computers, but the most popular (aside from Linux and Mac OS X, both of which are based on UNIX) are *BSD, IBM AIX, and Solaris (Figure 21.15). In look and feel, most versions of UNIX work like Linux, so most people today lump the two families together. Creating Your Network So now you’ve got a server and a couple of clients. What’s next? I want to access the information on the server from one of the client computers. In short, I want a network! To create a network, you need to connect a client computer with a server in some way. Most often, you’ll use a wire, but you could do it through radio waves to create a wireless connection. Let’s look at two common types of networks, then turn to network hardware. Network Types Figure 21.14: Linux server Networks come in many sizes and vary a lot in the number of computers attached to them. Some people connect two computers in their house so that they can share files and play games together—the smallest network you can have. Some companies have thousands of employees in dozens of countries, in contrast, and need to network their computers together to get work done. Network folks put most networks into one of two categories: LANs and WANs. 434 ▲ ▲ Figure 10: Typical server – Hey! That looks like my PC! (Photo courtesy of Dell) Lavish and Appealing Each chapter contains many highquality photographs, screen shots, and illustrations that help students assimilate the material to become computer literate. COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION Action! exercises prompt the students to try out the skills they’re reading about or challenge them to go deeper into a technology. Notes and Exam Tips keep students focused on essential information and provide insight into the IC3 exams. Concepts and Concrete Examples Scott Jernigan’s Computer Literacy explains the concepts behind technology and then goes the next major step by providing real-world, concrete examples of how to use the technology. Students come away from the book with knowledge about today’s world and also with the information needed to take and pass the Certiport IC3 exams. The CD-ROM in the back of the book comes with a complete set of simulations for each chapter. The students can walk through every step to perform essential tasks in Windows, Word, Excel, PowerPoint, Outlook, and Internet Explorer. Proven Style same approach, teaching students what they need to know at the same time as why the information is important. The writing is folksy rather than formal, and motivates the students to learn. Computer Literacy is not your usual dry, boring computer book! What’s My Motivation? Elements provide students with real-world examples of technology in action, so they understand not just the information they’re reading but why it’s important in the real world. Servers and Clients • Details, details, details! Network Machines Getting into the details of how networks work might seem a bit on the geeky side for a lot of you, but try it out. Networks are great, but they don’t do much for you when they don’t work. Knowing the process behind the network enables you to troubleshoot when something’s wrong.’‘I’ll just call a tech if the network’s down.’ Good thought, but what if no tech can get to your network before you absolutely have to have the term paper stored on the server and you can’t get in? Learn the process for your self-preservation! • • Networking Process Once you’ve assembled the pieces for a network, you can sit down at a client computer and access a file on a server. As cool as they may seem, networks aren’t magic. A whole bunch of stuff happens in the background when you access network resources. Let’s look at that process now. Johan has a slick new Windows XP laptop and wants to access an MP3 music file on his friend Maria’s computer. Two things need to be in place before anything else happens. Both Johan and Maria’s computers need to be connected to the same network, and Maria needs to share the folder that holds the MP3 file. The connection part should be easily implemented. If both computers have Ethernet NICs, they can plug them into two ports on a switch or hub. Sharing requires Maria to share and set permissions on her share to allow Johan to access it. Permissions define what a user can do with a particular shared file or folder, such as read it, delete it, and so on. How you share and set permissions varies among the various operating systems. In Windows XP, for example, Maria would open My Computer, right-click on the folder containing her MP3 file, and select Sharing and Security to open the folder’s Properties dialog box (Figure 1.20). By default, nothing is shared, so Maria would need to select the Share this folder radio button and give it a share name, such as Music (Figure 1.21). The default permission on a new share in Windows XP gives what’s called’“Read” access to everyone who has access to the share. Click on the Permissions button to open the Permissions dialog box and you’ll see what I mean (Figure 1.22). ▲ You’ll find two types of computers in most networks, servers and clients. Servers manage network resources (such as printers), provide central storage of files, and provide services for the users (such as having the e-mail server send your e-mail). Clients access those shared resources. Clients on a network are generally microcomputers running Windows or Mac OS, although you’ll run into Linux clients from time to time. Other devices, such as PDAs and mobile phones can be clients as well. Server computers come in quite a variety, from supercomputers, mainframes, and minicomputers, all the way down to microcomputers. The operating systems vary for servers as well, with many companies making versions of Linux and UNIX; Microsoft has several server-specific versions of Windows, such as Windows Server 2003, and Apple has a version of the Mac OS dedicated to serving, the appropriately named Macintosh OS X Server. • • Benefits, Risks, and Security • Creating Your Network • Sharing You’ve seen sharing before, way back in Part I, Chapter 1, “Field Guide to Identifying Computers in the Wild.” Glance back at that chapter and answer these questions: what can you share on a network? What is distributed computing and how does that compare with network sharing here? Would Johan and Maria’s network benefit from clusters? • • CHAPTER 1: NETWORK BASICS Motivational and Entertaining Written in an engaging, approachable writing style, Computer Literacy will grab and hold the attention of the readers. Knowing why they’re learning something helps focus attention and makes learning topics much easier. Networks come in a couple of types, including local area networks (LANs) that usually involve only a few computers, to wide area networks (WANs) that are composed of multiple LANs. The Internet is the biggest WAN of them all. Computers connect to a network in one of three ways: directly wired to a LAN via a cable from the computer to a LAN port, wirelessly to the LAN, and via a telephone line, what’s called dial-up networking. A typical network client has a network interface card (NIC) that connects to an Ethernet cable that connects to a central switch. The Ethernet standard defines everything about modern network hardware, from the physical size and shape of the RJ-45 connector on the end of the network cable to the electrical signaling that enables a NIC to break a message down into little pieces, 11 send them across the cable, and have the receiving NIC reassemble the pieces into a useful message. Wireless networks use infrared or radio waves to connect to a network. Most WiFi networks use a combination switch and wireless access point to enable connectivity. Modems enable computers to use regular analog phone lines to call in and connect to a network. Modems take digital signals and transform them into analog signals; receiving modems do the same process in reverse. • • Networks offer many benefits over standalone computing, such as communication, collaboration, sharing, cost, and centralized management. Networks enable you to exchange information via e-mail and to work remotely on projects with other people. You can share files and folders on networks, and lower costs by centralizing some machines, such as a shared server. Finally, central management of networked computers can enhance security. Networking computers together certainly adds both cost and risks. Dedicated server machines, cabling, and other network hardware can set you back; plus you have human cost for administration, maintenance, and troubleshooting. Sharing opens the door for thieves and hackers; being on the Internet makes you more susceptible to viruses and hacking as well. Security measures must be implemented on networks. You can encrypt data, require passwords and login, thus authenticating and authorizing a particular user to access specific things on the network. Applying the Principle of Least Access (PoLA) to all users makes a lot of sense. Give users only the access that they need and not a drop more. CHAPTER 1: PART 3 – SUMMARY write the rest of this book in Esperanto, that might make it a little difficult for you to get much knowledge about the Internet, e-mail, and other topics we have to cover. (Unless, of course, you read Esperanto!) By writing in English with Roman characters in a font that’s legible, in contrast, you can enjoy the information that I’m sharing and bask in the splendor of the magnificent prose that I modestly present. Networks require the same consistency of language and technology. The Ethernet standard defines everything about modern network hardware, from the physical size and shape of the connector on the end of the network cable—called an RJ-45, if you’re curious—to the electrical signaling that enables a NIC to break a message down into little pieces, send Figure 19: Ethernet connection close-up them across the cable, and have the receiving NIC reassemble the pieces into a useful message (Figure 1.19). If two machines do not have the same kind of networking technology—a common problem in the early days of computer networks—then they can’t network together. I won’t bore you with a list of all the networking technologies that have had a brief moment of glory and market share in the past. Suffice it to say that today, Ethernet is king. Outstanding Tools for Educators Each chapter finishes with a Chapter Review that not only provides a detailed summary, but also questions on key terms, a multiple choice quiz, essays that challenge students’ writing skills, and projects for them to accomplish both in class and on their own. ▲ Scott Jernigan and Total Seminars have proven with numerous best-selling books by Mike Meyers, Scott Jernigan, Martin Acuña, and others, and outstanding classroom experiences, that they can reach students at a fundamental level. Computer Literacy takes the CHAPTER 1: NETWORK BASICS Take Two! questions help students put together information from multiple parts of the book, challenging them to remember earlier lessons and integrate the knowledge with the current lesson. 21 Chapter Review portions of each chapter provide a detailed summary, quizzes, essays, and projects for the students to tackle, both on their own and with the guidance of their instructors. Each chapter includes… • Exam objectives that show the student the subjects they should learn • High-resolution photographs of important computer components • Screen captures for quick reference to subjects discussed • Illustrations demonstrating key points • Action! and Take Two! sidebars that walk the students through important processes and enhance critical thinking skills • What’s My Motivation! sidebars that help students understand why something that seems trivial has relevance to the real world • Exam Tips and Notes to provide assistance and insightful information • Summary of the important information in the chapter • Key term list and a fill-in-the-blanks key term quiz • Multiple choice exam (on the CD-ROM) • Essay questions challenging students to write about the chapter content (on the CD-ROM) • Projects for the students to complete in class and at home (on the CD-ROM) • Software simulations (on the CD-ROM) that walk the students through every step in performing fundamental tasks covered in that chapter “You must feel the Force around you; here, between you, me, the tree, the rock, everywhere, yes. Even between the land and the ship.” – Yoda, The Empire Strikes Back This chapter covers the following IC3 exam objectives: ■ IC3-1 1.1.4 Identify the role of the central processing unit ■ IC3-1 1.1.6 Identify the role of types of memory and storage and the purpose of each ■ IC3-1 1.1.8 Identify the flow of information between storage devices to the microprocessor and RAM in relation to everyday computer operations ■ IC3-1 1.2.1 Identify the types and purposes of external computer components ■ IC3-1 1.2.2 Identify the types and purposes of internal computer components ■ IC3-1 1.2.3 Identify the types and purposes of specialized input devices ■ IC3-1 1.2.4 Identify the types and purposes of specialized output devices ■ IC3-1 1.2.6 Identify ports used to connect input and output devices to a computer ■ IC3-1 2.1.1 Identify how hardware and software interact From the time you start your computer in the morning to the time you shut it down, you move data from one place to another. You input data using your keyboard and mouse; you download files from the Internet; you install software from CDs and DVDs. Each time you perform any of these actions, you move data between the many hardware components of your PC. The data flow follows three major phases: startup—where you provide electricity to the computer and the operating system loads; primary interaction, or what I like to call the dance phase—where you play a game, do word processing, save your work so you can use it later; the bulk of your time on the computer happens in this phase; and shutdown—where you close the program you’re working in and log off or shut the computer down completely. CHAPTER 2: GOING WITH THE DATA FLOW Going with the Data Flow CHAPTER 2: GOING WITH THE DATA FLOW 19 Phase One: Start Me Up! – The Computer’s Boot Process Boot Hill The term boot is short for bootstrap, as in “pulling yourself up by your bootstraps.” Techs adopted this term a long time ago to describe the computer startup process. There are two kinds of booting, a cold boot and a warm boot. Cold booting the computer means turning it on after it has been completely shut down with the power turned off. Warm booting means restarting a computer that is running. Let’s take it from Act 1, Scene 1. What happens when you press the power button on your computer? The short answer is that the computer system starts up, or in geek speak, it boots. The startup process has three overlapping phases: first is the poweron phase, then the hardware test, followed by the operating system load phase. Power-on The power-on phase takes place immediately after you press the power button. Electricity goes into the power supply—hardware that converts AC electricity from your power outlet into DC power that computers use— and from there to the drives and motherboard, waking the CPU. The CPU then wakes the system’s read-only memory—basic input/output system (ROMBIOS) memory circuit. The ROM-BIOS chip stores the computer’s “lizard brain,” its most basic commands and programs, including the collection of the hardware test phase diagnostic programs. Figure 2.1 shows a typical power supply; Figure 2.2 shows a ROM- BIOS chip on a motherboard. Figure 2.2: ROM-BIOS chip Hardware Test Figure 2.1: Power supply Once the ROM-BIOS wakes up, the computer runs basic hardware tests, asking the important hardware components to identify themselves and report their status (usually accompanied by beeps and bloops and blinking lights). If there is a problem with one of the components, the hardware test generates an error message for you. Macintosh computers will display a text message, for example, or an icon if it’s bad enough (see Figure 2.3). If there are no hardware problems to report, then the last thing that the hardware test does is locate and execute the files that start the operating system. Data Flow You’ll see the ROM-BIOS referred to as the System BIOS or System ROM by many computer people. All three terms are acceptable. Even this early in the boot process, the interplay between CPU, RAM, and storage devices comes into play. ROM stores the little programs that support the absolutely necessary, hard-wired into your computer devices: basic Figure 2.3: Unhappy Mac icons 20 COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION input devices, such as the keyboard, and fundamental output devices, such as the tiny speaker inside your case and the monitor. These little programs, called services, load from the very slow ROM into the shockingly fast RAM (Figure 2.4). The CPU does almost all the processing, as you know from Chapter 1, but RAM plays a fundamental part in the computing process. The CPU uses RAM like you use shortterm memory. If you want to do a complex math problem (and who doesn’t?!), for example, you would most likely need to use a book to look up the formulas and then, with numbers in your head, you could process the problem. If you didn’t have short-term memory, you couldn’t keep the necessary information in your head long enough to do the job, right? The CPU and RAM have that same relationship. The RAM holds every bit of data the CPU processes. Figure 2.4: The flow of data from ROM to RAM Operating System Load The operating system takes over the boot process from here, instructing the CPU to copy all of the necessary system files, services, drivers, and IBM-style PCs refer to the hardware test phase as the Power On Self Test (POST). Macintosh computers use the more generic term. Figure 2.5: Logon dialog in Windows CHAPTER 2: GOING WITH THE DATA FLOW 21 Figure 2.6: The boot process other files that make up the operating system from the hard drive to the computer’s RAM. As a final step, the operating system builds the user interface (using the video display adapter to draw the interface on your monitor), and soon you see the logon dialog or the icons next to user names (Figure 2.5). Figure 2.6 illustrates the boot process. The data keeps flowing Figure 2.7: The flow of data from hard drive to RAM The operating system files travel from a mass storage device, such as a hard drive, CD-ROM disc, or, in the ancient days, a floppy disk, through the motherboard into RAM (Figure 2.7). You saw this process with the tiny services programs, flowing from ROM to RAM. The process repeats here. I’ll let you in on a little secret. The flow of data follows the same process in almost every aspect of the computer! You’ll see this pattern again and again. Assuming there are no hardware problems, the whole process only takes a few seconds, and you’re ready to log on and start your computing session. Keep in mind that except for the previously-mentioned blinking lights, beeps (and any optional sound files, such as the soothing Windows Logon Sound audio file), and the sound of the disk drives spinning up to speed, there’s really not much to see. All of the action happens inside the CPU, RAM, and storage devices. Phase Two: The Dance – Interacting with the Computer Inside every computer is a small crystal called the clock or System Clock that sets the timing for all the other hardware . 22 Once you’ve booted up, you’re ready for the next phase, interacting with the computer. You can open a program—such as a word processing program to type a letter to your mother or write an essay from the essay questions at the end of the chapter. (Something you’re looking forward to doing, right?!) The computer processes your request, opening the application interface so you can type something in. The computer processes what you type and updates the screen to give you feedback. Rinse and repeat this COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION cycle many times quickly and you’ve got the whole’“interaction” part of the computing process. To make this interaction possible, you have to use input devices; the computer uses internal devices to process, then uses output devices to show your work. Let’s look at all three components of the interaction phase, including practical steps on opening applications and creating data. Input Devices Input devices enable you to give commands to the computer. You can type using the keyboard; click on icons and buttons using a pointing device such as a mouse, trackball, or touchpad; or speak using the microphone (Figure 2.8). More specialized input devices, such as joysticks and game pads, enable you to fly a simulated airplane more naturally than using a keyboard, for example, or enhance your game play in firstperson games (Figure 2.9). Some multimedia computers even use remote controls, just like the kind used for televisions. Some specialized input devices also enable you to add data to the computer. You Figure 2.9: Using a joystick in Microsoft’s Crimson Skies game can take a picture of your cat with a digital camera, for example, and then pull that picture into the computer so you can share it with friends, family, and random people who drop by your house (Figure 2.10). A digital video camera enables you to create your own movies, editing and watching them directly on the computer. A scanner enables you Figure 2.8: Standard input devices Other Specialized Input Devices Manufacturers have created an amazing variety of devices for inputting both commands and data. We created most of the artwork you see in this book, for example, using a drawing tablet (also called a digitizing tablet) and pen, rather than mouse and keyboard (see Figure 2.11). Barcode readers that you see at every supermarket take data— information about your food item—and bring it into the cash register (which is just another computer!). The scientific and medical communities use special, computer-based probes and instruments for cutting edge research and life-saving procedures. Alternative input devices, such as thumb mice and radically innovative keyboards, enable physically-challenged users to work with computers as readily as everyone else. Figure 2.12 shows a side-folded keyboard. Figure 2.10: Importing image from digital camera to computer CHAPTER 2: GOING WITH THE DATA FLOW 23 Figure 2.11: Graphics tablet and pen Figure 2.13: Typical scanner Installing Input Devices All this talk about input devices might have sparked your curiosity. (Even if it hasn’t, humor me here!) What sort of input devices do you have handy? Do an informal survey of teachers, family, and friends to find out what they use to input data or commands into any media, not just computers. Get creative here and write them all down. Here’s a hint: what input device will you use to write your list? Figure 2.12: Side-folded keyboard to create a digital image of an old-fashioned photograph, (just in case you’ve gone retro and started using a Polaroid). You can also use a scanner to import a type-written document directly into a word processing program, which is pretty cool when it works, a process called optical character recognition (OCR). Figure 2.13 shows a typical scanner. Finally, a whole host of devices enable you to input commands and data in the most basic way possible: poking them with your fingers. Every personal digital assistant (PDA), information kiosks, and automated teller machines that give out free money have touch screens that react to contact with your fingers or specialized stick (Figure 2.14). Figure 2.14: PDA in use Installing Input Devices Most operating systems support some input devices—especially keyboards and mice—straight out of the box, but others require a two step installation process. First, you plug the device into its proper spot. Second, you load a disc in your CD player and install a bit of support software so the OS knows what sort of device it now has. Physical Connections Some devices require that you reverse this process; that is, install the software before you plug in the hardware. Read the documentation that comes with any new device before you plug it in! 24 Devices connect to the computer’s hardware through connector ports, usually located on the back of your computer case, although you’ll find some universal connectors on the front or side of the case for quicker access. Portable computers typically have ports located on the back, sides, front— pretty much anywhere that the makers can fit them to give you the most access. Figure 2.15 shows the back side of a desktop computer. Ports come in several varieties, as you can see, but with one exception, you can’t go wrong when you plug in devices. Manufacturers key ports and connectors by giving them odd shapes, thus making it impossible to plug them in incorrectly. Traditional keyboards and pointing devices (such COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION It doesn’t hurt anything to plug the keyboard into the mouse port or the mouse into the keyboard port. They simply won’t work. If you do this accidentally, just turn off the computer, swap them out, and hope no one was looking! Figure 2.15: Input ports as mice) plug into the small round connectors labeled on the left (in Figure 2.15), and provide the exception to this rule. You can easily plug a keyboard into the mouse port, and vice versa, but your devices won’t work. Most PC makers color-code the mouse and keyboard connectors to keep you from getting confused: green for the mouse and purple for the keyboard. Most input devices today plug into one of the two universal ports, universal serial bus (USB) or FireWire, although you’ll see some devices plugged into legacy ports, such as the MIDI port shown in Figure 2.16. These ports are keyed and labeled with their own icons. You can’t mess up here. Warning: You can plug USB and FireWire devices in with the computer running and the computer will automatically recognize them. Do not do this with keyboards or mice, because you take the chance of burning out the ports. MIDI ports offer nothing either way—the computer won’t recognize the device automatically, but you’ll do no harm. Software Support Input devices usually require some software support programs installed so the operating system can communicate with them effectively. Although USB and FireWire tout the ability to plug and play devices—meaning you just plug them in, the OS recognizes them, and you can use them—this rarely works in the real world. The OS often recognizes the hardware, but doesn’t know how to talk to it! Hardware manufacturers provide a CD with small programs, called drivers, that the OS copies and loads into RAM to support the input device. Internal Processing Now that you have input devices sorted out, it’s time to get to work. You need to command the computer to open an application and the CPU MIDI stands for musical instrument digital interface, and indeed provided a way to connect electronic musical equipment to the computer, back in the day. Modern MIDIenabled instruments connect through USB or FireWire ports, just like everything else. Figure 2.16: MIDI port for legacy joysticks and other ancient devices CHAPTER 2: GOING WITH THE DATA FLOW 25 Figure 2.17: Selecting a program to open Figure 2.18: The flow of data when opening an application processes that command. The CPU does not work solo, though, requiring numerous other components to do both the processing and the next step, providing output of some sort. Opening Programs You can start an application in many ways, but the most common way in graphical-based OSs such as Windows and Macintosh OS X is to click the program icon in the Start menu (Windows) or double-click the program icon in the Finder (OS X). See Figure 2.17. Clicking and double-clicking, usually accomplished by a pointing device, tells the computer that you want it to run a specific program installed on the computer. Al Gore or Something Like That A computer uses algorithms (a set of pre-designed rules) to handle the data appropriately. For example, if you open up a Calculator application and use your keyboard to type 1+1, your computer will use an addition algorithm to sum the data. 26 Many Ways to Open Almost every OS offers you many ways to start a program. You can double-click the program’s icon on your desktop in Windows, for example, or click the Start button, select Run from the menu, and then browse to the location of the program’s executable file (the file that starts the program.) You can also double-click a data file associated with the program, meaning the OS knows to load a specific application when you select a specific file type. Selecting a text document (like a letter), for example, will start your text editor (such as Microsoft Word) open with that document ready to edit; choosing a music file (such as a song saved as an MP3) will launch your default media player (such as Windows Media Player or iTunes) and begin playing the song. This process is called file association. COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION Figure 2.19: Data flow from CPU to video to monitor The operating system and the CPU interpret your command and send commands to the hard drive to cough up the files for that application so they can be loaded into RAM. This process sounds familiar, right? To work with any application, the CPU must have that application loaded into RAM. Figure 2.18 illustrates the flow of data from hard drive to RAM so the CPU can work. What you see as a result of this processing requires more internal components. To change the display so you get the application interface, for example, the CPU has to send data and commands to the video card inside your system. The video card then processes the CPU’s commands and sends commands to the monitor so the monitor updates. All of this happens very quickly, but you see the change on the screen. Figure 2.19 illustrates this process. Creating Data Files Once you have an application open, you can create new files. Almost every productivity application—as opposed to games—has a File option on the main menu. Creating a file is as simple as going to File | New and then specifying what sort of file you want. Microsoft Word opens a separate dialog called the Task Pane to give you a bunch of choices (see Figure 2.20). Output Devices To engage fully in the “interacting with the computer” phase, you need properly connected and configured output devices. Output takes many forms, though, from standard feedback options of changing the display and making sound come out the speakers, to more specialized feedback such as force-feedback joysticks shaking your arm when you take a dive in your jet fighter. Other forms of output include printing, communicating over a network (like the Internet), and saving files to some sort of mass storage, such as a hard drive or compact disc. Feedback Devices Figure 2.20: Task Pane in Microsoft Word The monitor provides the most common way for the computer to communicate with you, showing that it has processed your commands by loading a program, changing some file, or simply moving the mouse pointer across the screen to match your hand movement. Figure 2.21 shows a pair of monitors. Creating You’ve read about it and probably listened to your instructor tell you about it; wouldn’t it be more fun if you just did it? So, what are you waiting for? If you have a Windows computer to work on, click the Start button and go to All Programs. What do you have installed on the computer? What about under the Accessories folder? Open up a couple of programs, such as Solitaire and WordPad. Use the latter to create a new document. What sort of feedback do you get from the computer when you work in these applications? CHAPTER 2: GOING WITH THE DATA FLOW 27 Figure 2.21: LCD vs. CRT: Fight! Types of Monitors Monitors come in two varieties, cathode ray tube (CRT) and liquid crystal display (LCD). CRTs use the same technology as most televisions and are large, heavy, and power-hungry. LCDs take up less desktop space, are lighter, and use less power than CRTs. Projectors offer a nice alternative to monitors, enabling you to put the computer image on a screen or white wall, rather than only on a smaller physical display (Figure 2.22). If the bulbs weren’t so expensive and energy-hungry, you’d undoubtedly see projectors replacing televisions as well as computer Figure 2.22: monitors! Projector Speakers give the computer another way to provide feedback (and playback, for that matter). Operating systems and applications can send sounds out when things go wrong or to acknowledge that they accomplished what you commanded. Media applications, like iTunes, can play music when requested. Good speakers can make a huge difference in games and in movie watching on the computer. Figure 2.23 shows a set of decent speakers. Figure 2.23: Speakers Voice synthesizers enable visually challenged folks to participate fully in the computer revolution, creating essential feedback from the computer that they otherwise wouldn’t receive. Many developers have software voice synthesizers that use your computers sound processor and speakers, but some manufacturers have external hardware devices that do the trick. For the latter, check out the good folks at www.freedomscientific.com. Hardcopy Despite the promise of the so-called “paperless office” that the computer age was supposed to usher in, most folks prefer to see their work printed out on good old-fashioned, tree-killing, finger-cutting paper. Modern printers enable you to turn your PC into a print shop and produce attractive 28 COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION text documents like reports and newsletters, as well as photos, banners, postcards, and other graphical documents (Figure 2.24). Networking Network output means sending data to another computer by means of networking hardware and software. To make it work, you’ve got to have a computer connected to a network or dialed in via a hardware device called a modem. Part 3 of this book covers networking in great detail, so we’ll leave that discussion for later. Storage Devices Opening a data file from within your application program causes the computer to copy the file from your storage media into the system’s RAM (Figure 2.25). This is your editable, “working” copy of the file. You’re free to make changes by adding text, entering numbers, slaying dragons, or doing whatever the application program does. Figure 2.24: Printer Plotters Figure 2.25: File stored and in use As you’ll recall from earlier in the chapter, the CPU can work with files and programs held in RAM, its short-term memory. As you interact with the computer, the CPU updates the contents of RAM according to what you do, and that’s great. You can work on drawing a masterpiece, for example, and what you see on your monitor also appears (in a slightly altered format) in RAM. There’s just one problem. If RAM loses power, all the data it holds just goes away. Poof. Gone forever. That’s why it’s important to save your work. Saving a data file copies it from RAM onto a mass storage device, such as a hard disk, where it’s retained permanently (Figure 2.26). All applications give you methods for saving a file, such as clicking a Save button, going to File | Save, or pressing [Ctrl + S] (for Windows) or [Cmd + S] (for Macintosh) on the keyboard. Figure 2.27 shows the saving dialog in Word. People have used different types of media for data storage through the years, from stone tablets to magnetic reel-to-reel tapes. Three technologies dominate the current storage scene for computers: magnetic, optical, and solid state. Hard drives, floppy disks, and Zip disks save information magnetically on platters. Hard drives provide the primary fixed mass storage in almost If you need to print something huge, like poster sized, you need to walk away from the typical home and office print device and embrace the goodness of the plotter. Plotters look like scaledup printers and run anywhere from $2000 to $20,000 and up (in U.S. dollars), but they’ll print your big pictures just fine. Plotters produce large-scale, detailed printouts, such as architectural drawings, blueprints, maps, and posters. Keep an Eye on Your Applications with Task Manager The Windows Task Manager utility lets you view the programs and processes that are currently stored in memory and running on your computer. Press the [Ctrl] + [Alt] + [Delete] key combination once to bring up the Windows Security dialog box, and then click on the button labeled Task Manager. Running programs are listed on the tab labeled Applications. CHAPTER 2: GOING WITH THE DATA FLOW 29 Figure 2.26: File being copied from RAM to hard drive Random Memories The name Random Access Memory is a bit misleading. There’s nothing random about the way that RAM stores data.’“Random” simply means that any part of memory’s storage area can be read as easily as any other part. It doesn’t have to be in sequence. every computer. Figure 2.29 shows a hard drive open to reveal the platters inside. CD- and DVD-media drives use optical lasers to read information stored on shiny discs, like the AOL discs found on every street corner. These optical drives provide the most common form of removable mass storage on computers. Figure 2.29 shows an optical drive. Figure 2.27: Saving in Word Acronym Soup CD- and DVD-media drives and discs use different designations, such as CD-ROM, CD-R, CD-RW, DVD-ROM, and DVD+RW. The initials stand for variations of the same optical technology, offering different storage capacity (DVDs can store many times more data than CDs) and the ability to write or rewrite data on the same disc. • CD-ROM and DVD-ROM are read-only memory formats. The data that’s stored on CD-ROM and DVD-ROM discs can’t be changed. • CD-R and DVD-R stand for recordable. These types of optical media can be recorded onto, or burned, if you’ve got the appropriate type of CD or DVD optical drive. This kind of optical media can only be recorded once, however. • CD-RW, DVD-RW, and DVD+RW stand for rewritable. These types of optical media can be recorded and re-recorded onto numerous times. Because the different types of CD/DVD drives follow the same standards, disks recorded on one type of device should be readable by another type of device. That is, a disk burned on a CD-RW drive should be readable on any CD-ROM and CD-R drive. Older CDbased media drives can’t read DVDs, but DVD drives have no trouble reading CD media. Many modern drive devices are combination drives, meaning that they can read and write to any type of CD or DVD media. 30 COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION Figure 2.29: CD-RW drive and disc Figure 2.28: Hard drive Figure 2.30: Flash memory devices The solid state flash memory offers a lot of storage in a small container, plus it’ll retain information without electricity. Manufacturers package flash memory in a number of different formats, such as removable USB thumb drives; postage-stamp-sized SmartMedia, Secure Digital (SD), and Compact Flash cards; and Memory Stick cards that are roughly the size of a stick of gum (Figure 2.30). Portable electronics like MP3 music players, digital cameras, cell phones, and PDAs, as well as PCs, use Flash memory cards. Connecting Output Devices Like with input devices, operating systems support some output devices straight out of the box, but others require a two step installation process. First, you plug the device into its proper spot. Second, you load a disc in your CD player and install a bit of support software so the OS knows what sort of device it now has (or vice versa—software then installation). Physical Connections Output devices connect to the PC’s hardware t h r o u g h connector ports on the case and Remote Storage In today’s networked world, mass storage doesn’t necessarily have to be physically attached to a particular computer. One of the biggest benefits to networking is the ability to share mass storage devices on remote computers on your LAN, or on servers located “out there” on the Internet somewhere. This is collectively called remote storage, or sometimes virtual storage. Figure 2.31: Output ports CHAPTER 2: GOING WITH THE DATA FLOW 31 Some smaller devices, such as PDAs, can network wirelessly using infrared light. These devices use appropriately named nfrared ports to connect. Legacy Connector Ports It seems like newer and better is the order of things in the computer world. Nonetheless, some older technologies persist long after you’d think they’d disappear. These kinds of technologies are called legacy technologies. Legacy technologies are retained on newer computers for one reason: so that older hardware will still work on them. Techs call this backwards compatibility. Two examples of legacy technology are the serial and parallel ports. Hardware that may connect to serial ports includes external modems and specialized print devices such as label printers. Devices that use the parallel port include external storage devices and scanners. The most common use for this connector, however, is for printers. In fact, many folks call the parallel port the “printer port,” which isn’t entirely correct, but it’s not worth arguing about, either. through data cables inside the case. Figure 2.31 shows the back side of a desktop computer. Your monitor connects to one of the video ports, either the traditional 15pin VGA port or the newer DVI port (see Figure 2.32: Figure 2.31). Both External FireWire types of connectors are keyed, so hard drive you can only plug them in correctly. Audio ports on most computers are the common, mini-audio sockets seen on most small consumer audio devices. Computers typically have three color-coded audio ports: a green speaker output port, a pink microphone input port, and a blue auxiliary input port. Networks are collections of computers that interconnect and share data and other resources. You connect your computer to networks through two different devices, a modem and a network adapter. The connectors for these devices are called RJ-11 and RJ-45 connectors, respectively, and you’ll hear their ports referred to as telephone ports and Ethernet or network ports. Almost every other output device connects to one of the universal ports you saw earlier in this chapter, USB and FireWire. FireWire seems limited to higher-end printers and external hard drives, whereas you can get almost any device in USB. Figure 2.32 shows a hard drive with a FireWire connection. Internal drives connect to the motherboard via ribbon cables, usually flat 34-wire, 40-wire, and 80-wire gray affairs. Modern hard drives use a smaller, 8-wire cable. Figure 2.33 shows a motherboard with a hard drive and CD-media drive connected. Figure 2.33: Motherboard out of the case with hard drive and CD-media drive connected Software Support Output devices aside from the monitor require some software support programs installed so the operating system can communicate with them effectively. Hardware manufacturers provide a CD with drivers that the OS copies and loads into RAM to support the output device. You should leave installing and uninstalling mass storage devices to trained, CompTIA A+ certified technicians. 32 COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION Phase Three: Park It – Properly Closing Programs and Shutting Down the Computer When you’re driving from one location to another, upon arrival, do you simply step out of the car and leave it running? Of course not! You roll up the windows, shut off the engine, and lock the doors. If you’ve brought things with you, like a backpack, wallet, or cell phone, you take those things when you leave the car. Well, it’s the same idea with your computer. Do you simply walk away when you’re done with your work? Not if you’re smart! There’s a proper order to making sure that your work is saved and your computer secured before you walk away from your desk. This is most important in an environment where you share the computer with other users. You should close things down properly for three reasons: avoiding corruption of your applications or operating system, personal security, and doing your part to save the planet. Sounds like quite a stretch for simply shutting down a computer, but let’s take a look. Anti-Corruption One of the first things that you should learn as a computer user is that you should never turn off the computer while the operating system or applications are running. This is true for Windows, OS X, and all versions of Linux, (although not true for PDAs running PalmOS or PocketPC). The reason for this is simple: to prevent data loss. Data, application, and OS files held in RAM are in a vulnerable state. If you mistakenly click the wrong button, or if your computer loses power, then the data may be flushed out of RAM without saving it to disk. In the case of data files, this means any work that wasn’t saved is gone. With program and OS files, this can mean file corruption that may prevent them from running properly the next time you fire them up. Shutting down properly involves three or four steps. First, save and close any data file you’re working on. We looked at this process earlier in the chapter. Second, close any running applications. You can do this in quite a few ways, such as clicking the Close button. In Windows programs, it’s the little X button located in the top right-hand corner of the application window, as you can see in Figure 2.34. You can also go to File | Exit on the main menu. Most applications respond to a hotkey combination, such as [Alt + F4] in Windows or [Apple + Q] in OS X. The third and fourth steps involve logging out of the operating system and powering down the computer. Doing these steps properly avoids file corruption, but also provide other benefits, such as security and energy savings. Figure 2.35: Letter supposedly from “Mom” Unlike with input devices, you run no risk plugging external output devices in while the computer is running. Playing with Plugs You’ve read about external output devices, so now it’s time to play with them. What’s plugged into your computer? Try unscrewing and unplugging the monitor cable from the video port. (Trace the connection from the back of the monitor.) What kind of video do you have? What was the effect of unplugging the video cable when the computer was running? Try plugging it in only part way. What does that do to your screen? What other output devices do you have? Figure 2.34: Close button What’s the Worst that Can Happen? Information stored in RAM while you’re using an application includes not only your data files and application program files, but also your essential OS files. In some cases, incorrectly shutting down the computer will damage the OS itself! CHAPTER 2: GOING WITH THE DATA FLOW 33 Personal Security Fast User Switching By default, Windows XP Home allows you to log off without closing your applications, using what’s called Fast User Switching. You can do this semi-log off by pressing the [Windows key + L] keyboard combination. Have you ever received a letter from someone? How did you know the person who wrote it is the person you think wrote it? Handwriting recognition might help, but what if the letter is typed? What would you do if you received the letter in Figure 2.35. Seems like a pretty exciting opportunity, right? Mom never wrote that letter. It’s a scam; but if the letter had your mom’s address as the return address and the postage information seemed correct, you might have second thoughts. In the world of computers, the potential for such identity theft cranks up to very high. If you walk away from your computer, still logged in, the next person who sits down at that computer can become you as far as the rest of the world can tell. The thief could use your computer to hurt others, to steal, to do all sorts of mischief, all while appearing to be you. Guess who will take the heat for the evil deeds? You will. When you walk away, you need to log out. To log out in Windows, go to Start | Log Off or press [Ctrl + Alt + Delete] once and click the Log Off button in the Windows Security dialog box. To log out in OS X, go to the Apple menu and select Log Off. Couldn’t be simpler! Green Acres Computers use electricity, some at a huge rate, and unfortunately for computer users, electricity doesn’t grow on trees. As computers go into service in every aspect of life, the demand for electricity goes way up. The fourth step in the proper shut down process, therefore, is to close the operating system and power off the computer. This generally takes a single action on your part. In Windows, for example, rather than simply logging out, you can go to Start | Shut Down to log out, close the OS, and power down. Because it takes more electricity to power up a computer than to leave one sitting idle, you should follow this basic rule with your computer use. Power up when you want to use the computer and then power down at the end of the day or when you’re done using it for the day. 34 COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION ■ The flow of data starts with the boot process. First you turn the power on, waking the CPU. The CPU then communicates with the ROMBIOS memory chip to start the hardware test process. The ROM-BIOS memory chip contains vital programs that enable your computer to identify its hardware and start itself when you press the power button. ■ The operating system takes over, loading from the hard drive into RAM and presenting the user with a user interface. You can log in at that point. Phase Two: The Dance – Interacting with the Computer ■ Once booted, you can get to work by typing a command or double-clicking an icon or program file. The computer processes your request, opening the application interface so you can type something in. The computer processes what you type and updates the screen to give you feedback. ■ Input devices enable you to give commands to the computer. You can type using the keyboard; click on icons and buttons using a pointing device such as a mouse, trackball, or touchpad; speak using the microphone; or game with a joystick or game pad. ■ Some input devices also enable you to add data to the computer. You can take a picture of your cat with a digital camera, for example. A scanner enables you to create a digital image of an old-fashioned photograph. You can also use a scanner to import a type-written document directly into a word processing program, a process called optical character recognition (OCR). ■ Devices connect to the computer’s hardware through connector ports, usually located on the back of your computer case. Manufacturers’key ports and connectors by giving them odd shapes, thus making it impossible to plug them in incorrectly. Most input devices today plug into one of the two universal ports, universal serial bus (USB) or FireWire. ■ Input devices usually require some software support programs installed so the operating system can communicate with them effectively. Hardware manufacturers provide a CD with small programs, called drivers, that the OS copies and loads into RAM to support the input device. ■ You can use input devices to start an application. The most common way in graphical-based OSs such as Windows and Macintosh OS X is to click the program icon in the Start Menu (Windows) or doubleclick the program icon in the Finder (OS X). The operating system and the CPU interpret your command and send commands to the hard drive to get the files for that application so they can be loaded into RAM and the CPU can process them. ■ Once you have an application open, you can create new files. Almost every productivity application—as opposed to games— has a File option on the main menu. Creating a file is as simple as going to—File | New and then specifying what sort of file you want. CHAPTER 2: SUMMARY Phase One: Start Me Up! – The Computer’s Boot Process ■ To engage fully in the “interacting with the computer” phase, you need properly connected and configured output devices. Output takes many forms, such as standard feedback options of changing the display and making sound come out the speakers. Other forms of output include printing, communicating over a network (like the Internet), and saving files to some sort of mass storage, such as a hard drive or compact disc. ■ Three technologies dominate the current storage scene for computers: magnetic, optical, and solid state. Hard drives and floppy disks save information magnetically on platters. Hard drives provide the primary fixed mass storage in almost ev CHAPTER 2: GOING WITH THE DATA FLOW 35 CHAPTER 2: SUMMARY 36 ery computer. CD- and DVD-media drives use optical lasers to read information stored on shiny discs. These optical drives provide the most common form of removable mass storage on computers. The solid state flash memory offers a lot of storage in a small container, plus it’ll retain information without electricity. Manufacturers package flash memory in a number of different formats, such as removable USB thumb drives and postage-stamp-sized SmartMedia. ■ Output devices connect to the PC’s hardware through connector ports on the case and through data cables inside the case. Your monitor connects to one of the video ports, either the traditional 15-pin VGA port or the newer DVI port. PCs typically have three color-coded audio ports: a green speaker output port, a pink microphone input port, and a blue auxiliary input port. Almost every other external output device connects to one of the universal ports, USB and FireWire. Internal drives connect to the motherboard via ribbon cables, usually flat 34-wire, 40-wire, and 80-wire gray affairs. Modern hard drives use a smaller, 8-wire cable. COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION Phase Three: Park It – Properly Closing Programs and Shutting Down the Computer ■ You should never turn off the computer while the operating system or applications are running. To do so runs the risk of corrupting your application or operating system files. ■ Shutting down properly involves three or four steps. First, save and close any data file you’re working on. Second, close any running applications, often by going to File | Exit or File | Quit. The third and fourth steps involve logging out of the operating system and powering down the computer. In Windows, go to Start | Log Off or Start | Shut Down; in OS X, go to Apple menu | Shut Down. Algorithms Plug and play Boot Power supply Digital camera Printer Drivers Projector FireWire Remote storage Flash memory Read-only memory-basic input/ Game pad output system (ROM-BIOS) Input devices Ribbon cable Joystick Scanner Key Services Keyboard Solid-state storage Magnetic storage Speakers Microphone System clock Monitor Thumb mouse Mouse Touchpad Musical instrument digital interface (MIDI) Trackball Optical character recognition (OCR) Universal serial bus (USB) Optical storage Video card Output devices Voice synthesizer Plotter CHAPTER 2: GOING WITH THE DATA FLOW CHAPTER 2: REVIEW Key Terms 37 CHAPTER 2: REVIEW 38 Key Term Quiz Use the Key Terms list to complete the following sentences. Not all the terms will be used. 6. Hard disk drives and floppy diskettes are examples of __________________. 1. The _______________ converts alternatingcurrent (AC) electricity that comes out of your wall socket into direct current (DC) used by the computer. 7. John can use a __________________ to give voice commands to his computer. 2. A ________________ makes a digital image of a text document or photo, which you can then edit on your computer. 3. The __________________ draws the images that you see on your display monitor. 4. __________________ devices access data stored on reflective disks using laser light. 5. External devices that need consistent, highspeed access to the computer, such as storage drives and digital video camcorders, connect to the computer using __________________. COMPUTER LITERACY: YOUR TICKET TO IC3 CERTIFICATION 8. _________________ uses the same storage technology as RAM, but is non-volatile (doesn’t need constant power to retain data.) 9. A visually-impaired user could get feedback from the computer with a __________________, thus enabling him or her to enjoy interacting with the computer. 10. A __________________ is a type of printer used to produce large, detailed drawings such as blueprints.