Lesson Objectives To learn the most important parts of your computer To learn what parts of a computer's hardware allow you to give the computer information (input) and what parts of the computer's hardware allow the computer to give information to you (output) To learn the unique features of a computer mouse and a computer keyboard To learn about where a computer processes and stores information To learn what computer software can do and how it works with computer hardware To learn about the Microsoft Windows operating system   The Lesson   In the Introduction to Information Literacy, you learned how to use two tools to get you through the lesson, the computer screen and the computer mouse. In this lesson you will continue to use these tools and to learn about the other parts of the computer that make your search for and use of information speedy and effective.   The Parts of Your Computer The computer you are working with has four important parts that you can see: the screen and the mouse (that you have already met), and the keyboard and a systems unit next to the screen or under it. Your computer may or may not have two additional parts, a printer and a modem.     The computer you are working with has four important parts that you can see: the screen and the mouse (that you have already met), and the keyboard and a systems unit next to the screen or under it. Your computer may or may not have two additional parts, a printer and a modem.   Visit the Exploratory: Build a Computer System! Currently, there are two major types of computers you are likely to encounter. These two types are sometimes called platforms. One platform is referred to as Apple or Macintosh and one platform is called IBM or PC. The term PC is a little confusing. It stands for Personal Computer. Computers made by the company Apple may be called personal computers, but some people insist that if you call it a PC, it has to be a computer that fits the IBM platform. Regardless of your platform, computers all have certain parts in common and share certain principles about the way they work. These are the important concepts that you will be learning about computers: computer hardware computer storage computer software operating systems   Computer Hardware A good way to recognize computer hardware is to think of it as the things about a computer that you can get your hands on. At the beginning of this lesson, you identified several parts of the computer that make up visible computer hardware: the screen, the mouse, the keyboard and the big box. You may also see a printer and a modem.   Input and Output The computer mouse and the keyboard are both hardware devices that allow you to communicate with the computer. It is through these devices that the computer can learn what your desires are. These two devices are called input devices. The computer screen, or the monitor, is the way that the computer communicates with you. The computer monitor is also called an output device. The printer is another output device.   More on Input: The Mouse You spent a little time in the introduction learning how to use the input device, the mouse. You learned that when you move the mouse on a pad next to your computer, a white arrow/vertical black line on the screen moves in correspondence. You also learned that when you click the left mouse button when the arrow is pointed to a particular area of the screen, you can control what happens on the screen. In the introduction, you made the screen scroll by pointing and clicking the mouse over a triangle that is part of the image on the screen. By pointing and clicking the mouse you can also place on the screen a point known as the cursor. The cursor is the point on your computer screen where your computer is ready for input. It may appear as a still or flashing verticle or horizontal line or as a box. When you type, information will be entered at the point of the cursor.   Visit the Exploratory: Run your mouse through a maze!   More on Input: The Keyboard The computer keyboard offers a range of special functions that are important to master in order to use a computer best as a tool for information literacy. In addition, some special function computers you use will not have a mouse and will only allow you to communicate with the computer through its keyboard. Knowing how to touch-type will enable you to work quickly when you use a computer. Knowing some keyboard basics are essential for survival when using a computer. The diagram below highlights important features of a computer keyboard: Sometimes computer keys work together to perform a pre-defined operation. It is important when using these combinations of keys that you press all of them at the same time. Stretch those fingers! There will be times when you are using a computer when the only way the computer will register your message is if you hit the enter key after you have typed in some information. This is true with database or searching programs such as an electronic library catalog or a search engine on the World Wide Web. Unlike a typewriter, however, when you are using your computer for word processing, you do not have to hit the enter key at the end of a line. Word processors will automatically wrap the typing around to the next line. Remember to hit the space bar in between words. Many computer programs have a dictionary built into them, but the computer does not automatically know where words break. The tab key will allow you to jump ahead a few spaces when your computer is working as a word processor, or down or over to another fill-in area when you are working with a computerized form. The shift key allows you to capitalize letters when you are using your computer as a word processor. In addition, the shift key, as well as the control and the alt key are keys that are often used in combination to perform special functions with your computer. The top row of the keyboard has keys called function keys. These keys are labelled with the letter F and the numbers 1-12. Before the Windows operating system became the major operating system for personal computers, many computer programs were written which assigned special capabilities to the computer keyboard function keys. Some programs you use may instruct you to use these keys. The back arrow key located on the right side of the row of number keys allows you to move the cursor to a position where you were previously. Moving backward with this arrow key may or may not erase the information that was previously typed there. This depends on what software you are using. The home key will take you to the beginning of a line on the screen and the end key will take you to the end of a line. Page Up and Page Down allow you to move through complete screen in a single step. Remember that when a file is brought onto a computer screen work or presentation area, the file appears as though it is on a single, long sheet of paper that is as long as the information it holds requires it to be. The arrow keys also allow you to move through your screen of material. The insert key allows you to type over material you have already typed. The delete key allows you to erase. The print screen key may work alone or may work in combination with another key to allow you to print what is on the screen. Using print screen is a quick and dirty alternative to more elegant ways of printing your files from any Windows program. The numeric pad on the right side of your keyboard allows you an alternative method of using the computer keyboard numbers for calculation purposes. The numeric pad numbers are labelled for multiple functions.     Visit the Exploratory: Assemble a Keyboard!   Remember when you are using a computer these important communication, or input and output points. Your computer will not know that you are sending it messages unless you have used the mouse or the keyboard; your computer may have the answer to your question but you'll have to look at the screen to read it.   Processing The systems unit is the most important piece of computer hardware. The systems unit has slot holes in the front where you will be able to put information storage devices and buttons to turn the computer on and off. In the back it has plug holes where you can attach the other pieces of computer hardware with wires. In addition to its visible hardware, a computer has hidden hardware, much of which is housed in the systems unit. Hidden hardware are the parts of the computer that you can get your hands on when you open up your systems unit. One of the two most important pieces of hidden hardware is the motherboard. On the motherboard lives the CPU, or the central processing unit. The CPU is a small component in the computer that is capable of some very big functions. The CPU does the calculations, runs the programs, controls what the computer does, produces output and processes input. Another important piece of hidden hardware is a hard drive, or a highly compacted electronic storage device. Other important pieces of hidden hardware that may be in your computer include electronic curcuit boards, smaller than the motherboard, that enable your computer to show video clips or offer sound. In addition, if your computer has a modem, this may be hidden in the computer. Your computer may also have a circuit board that allows it to be part of a network (more on modems and networks in the next chapter).   Computer Storage One distinguishing feature of personal computers as they have evolved during the past decade is their capacity to store large quantities of information in a small space. Computers store information in units called bytes, or multiples of bytes such as megabytes and gigabytes. The more bytes your computer has, the more storage area it has. Computer storage is also called memory. In addition to the hard drive, the computer hardware storage device that stays in your computer all the time, your computer can store information on portable floppy disks (5 1/4" thin plastic squares) and on CD-ROMs similar to your music CD's. The hard drive, floppy disks and CD-ROMs are storage containers that hold the information you need whether or not your computer is on. They are like your clothes closets and drawers, holding all your stuff for when you need it. Your computer has another storage area in it called RAM, or random access memory. RAM is housed on your computer's motherboard, along with the CPU. RAM is only in use when your computer is on. Any information you see on your computer screen is stored on RAM. Any information your computer is currently working on is stored in RAM. RAM is like the chalkboard your teacher writes on in front of the classroom. The information is available until the board is erased. If you do not copy on to paper, a more permanent storage device, the notes your teacher writes on the board, after the board is erased, the information is gone. Remember that RAM is a temporary sort of storage every time you are working at your computer. Because you can see what you want while your computer is turned on and the information in RAM is on the screen, does not mean that the computer will retain this information for you after you turn off the computer. As you work with information on your computer, you will get used to the idea of saving the work you have done so that information that first enters the computer through RAM, will be put into one of the permanent storage mediums already described.   Visit the Exploratory: Share Your Memories!   Computer Software Computer software is the instructions, or programs, that give a computer the capacity to perform different functions or applications. Software is what allows you to type a paper for school (word processing software), calculate a budget (spreadsheet software), search an index for a collection of magazines (database software) and play electronic chess (game software) all at the same computer. A computer must be loaded with the software you want to use in order for your computer to be able to perform its specific functions. When a computer is loaded with the software you want, the software lives on a piece of the computer hardware -- either on a floppy disk, a CD-ROM or on the hard drive when it is not in use, or in RAM when that piece of software is active. Two computers sitting side-by-side in a classroom or an office may not be able to do the exact same things. It all depends on what software is loaded into each computer. Computer storage space decides how many different pieces of software can be kept in a single computer at one time. Take a look at a box of computer software one day and read the label that says "systems requirements." One of the requirements for running a new piece of software is how much storage space (in RAM and on your hard drive) is currently available on your computer. If your computer is already loaded with a lot of different pieces of software, you might not have room to add a new piece of software.   Visit the Exploratory: Install Some Software!   Software can be moved or changed. However, because software is written to allow your computer to perform certain functions, you probably will not want to change the computer software or you will lose your ability to do what you want with your computer.   Operating Systems - Microsoft Windows The operating system is the software that allows people to communicate with the computer hardware. The operating system of your computer acts as a master controller regardless of what specific function or functions your computer performs. The operating system your computer uses is called Microsoft Windows. Windows is the framework you see on your computer screen, regardless of what operation your computer is about to perform. Windows provides a consistent, mouse-dependent approach to running different types of applications software on your PC. Any time you run a computer program using Windows, you will be able to use the same techniques to perform the same type of actions. In addition, Windows often gives you more than one way of performing the same action. Two things that distinguish Windows from the operating system that proceeded it, DOS, are its ability to let you run more than one program or perform more than one computer function at a time (known as multi-tasking), and its preference for mouse-clickable icons over typed-in commands. The opening screen in Windows offers you pictures, or icons, with the names of some of the programs loaded on to your computer and a Start line at the bottom of the screen. When you click the left mouse button on the word Start, a menu box appears, offering you some options. The most important option is the choice Programs. When you select Programs, a complete list of the software programs loaded in your computer appears in a second menu box. You can click to select any of the programs you want to use from the list of programs or you can click on the icon with the name of the program you want. You can click on Start again if you want to select another program as well. The Start button also allows you to find at random anything that is loaded on your computer, run or install a new program and shut down your computer. There are some useful things to keep in mind when running a program with the Windows operating system.   The Window A window for a computer program provides both communication areas that will allow you to talk to your computer when you click on them with your mouse and a blank work area where you create something (a text document, a drawing, etc.) or a presentation area where the computer will show you something (data, a web site, etc.).   In Windows, more than one window or program can be open at a time.   The name of each program will appear on the top line of the window for that program.   When you click on the top line of a program window, that program becomes active, no matter how many windows you have open.   There are three buttons on the upper, righthand corner of each window. You can remove the program window from the screen temporarily by clicking the left button, you can shrink the size of the window by clicking the middle button and you can close the window by clicking the x.   When a program window is shrunken in size, you can move it around the screen by pointing and clicking to the top line of the window and moving the mouse to reposition the window.   The Command Line Every program you run in Windows has a command line underneath the name bar.   Common command words include (from left to right) file, edit, view, and help. Individual programs may have additional command words, but these four are usually found in every program that runs in Windows.   When you click the left mouse button over a command word, and then lift your finger from the mouse button, a drop-down menu appears and stays in place. (When using an Apple computer, you need to keep your finger on the mouse button to keep the menu in place). The drop-down menu offers you additional commands that you may select with a left mouse click.   When you click on one of these additional commands, Windows may immediately perform the desired action or present you with further choices in dialog boxes.   Dialog Boxes offer you clickable options. Some dialog boxes may look like a series of paper files as they appear in a filing cabinet. Click on the header for each file to explore all your options. Some dialog boxes offer you multiple pull-down menus, clickable circles called radio buttons or check-boxes that allow you to make your choice. To control the dialog box, you will usually find buttons labeled apply, ok, cancel and close at the bottom or on the righthand side of the dialog box.   A file is the material you are working with using one of the computer programs offered on your PC (your term paper, for example, is a file that you are working with when you are using your computer for word processing). The file commands allow you to do things with this file as a unit. For example, you can open or close a particular file or you can save or print an opened file using the file command. You can also exit the program from this command.   The edit command allows you to manipulate portions of a file you are working with in the work area of your program window. Often, you will use the edit options along with the mouse's ability to block off pieces of text. When you left click the mouse over something in your work area and drag the mouse along, material in your work area will become highlighted, or, designated for further action. You may want to cut out and eliminate or cut out or copy and paste a passage of text somewhere else in your document.   The view command controls what parts of the program window will be shown to you, in addition to the work or presentation area. The view drop-down menu allows you to check off what you would like to see. A toolbar, for example, is a common feature in many Windows programs. If the drop-down menu for view shows toolbar checked off, you will see a row of small icons or pictures underneath the command line. These icons work as a short cut to frequently used commands. When you hold your mouse over these icons, a banner explaining what they do will show under each.   The help command will offer you topics about the particular program you are using.   Visit the Exploratory: Try Out Microsoft Word! Want to learn more? Take the quiz!