Lesson 1: Materials Models for Hard Drives
Objective(s) - students will be able
1. To discuss and provide examples of how materials are used in hard drives
2. To define and provide examples of hard drive functions
3. To define and provide examples of hard drive dimensions and the units used to measure them
4. To apply the concepts of function, independent and dependent variable to describe relationships between material models using multiple representations of functions
5. To classify the relationship between variables associated with material models
6. To pose questions about the performance of material models
7. Describe the difference between material models
8. Define material models
Relevant Vocabulary, Terms and Symbols
Materials, dimensions, sectors, file allocation tables, access time, transfer time
Strategy
Computer hard drives hold an enormous amount of data or information. It is very important that all of the data is well organized. That way it is easy for the computer to find what it is looking for. Knowing how a computer’s organization system works will help you to find what you are looking for. Computers use files and folders to organize data.
What is a file?
A file is a collection of data that is stored together. Files can be stored on a hard drive, a floppy disk, or a CD. Everything that a computer does is based on data stored in files. You can do lots of things with files - create them, name them, rename them, save them, or delete them. Certain files can even be looked at, listened to, and run. In some ways, files are like television shows. All TV shows have 3 things, just like computer files: • Name • Location • Length Just as you recognize your favorite TV program by its name, you can also recognize a file by its name. File names often consist of 2 parts: name and type. There are many different types of TV shows - comedies, dramas, cartoons, sports shows, game shows, etc. Similarly, computer files come in different types - text files, graphic files, program files, e-mail files, etc. In many computer systems, files are named so that you know what type of file it is just by looking at the abbreviation behind the name. A period is used to separate the name from the type, like this: “name.type”. An overhead slide show would nicely show the attributes of the CISC and RISC Hard Drives. Ask questions about the characteristics of Materials used in Hard Drives, i.e. “are these related? How is that so?” Provide encouragement and feedback.
Student tasks
1. Classify TV show titles in 2 parts like computer files, they would give the name of the program, followed by a period, followed by the type of show it is. It might look like this: “Sillykids.toon” or “EmergencyRoom.drama” or “Football.sport”!
One important thing that you should know about file types or extensions is that they are always written as abbreviations, usually with 3 letters. For example, a text file is shown as .txt when you are using the program notepad or as .doc when you use Microsoft Word and an executable program file is shown as .exe. You may not always see the extension on a file name, because many PCs offer the option of turning off the extension. Even though you don’t see it, the computer still does. On the Macintosh system, however, the practice of naming files with extensions is not always followed; but you can see what kind of file it is by the icon or ‘kind’ identifier in the directory listings. Universal extensions you’ll see are .sit (a compressed stuffit file), .hqx (a binhexed encoded file), .pdf (Adobe Acrobat file). Web pages (no matter what system) always use extensions to identify the kind of file - .htm or .html for the web pages, .gif for gif graphics, .jpg for jpg graphics and so on.
Files are stored in certain places within your computer, much like TV programs are shown on certain channels. So, to find a file you must know where it is located, just like you must know on what channel to find your favorite TV show. If you forget what channel a TV show is on, you can either flip through channels until you find the program or you can look in a TV guide to find the information you need quickly. The quickest way to find files on most computers is to use Search. This is a type of search program where you can type in the name of a file and the computer will search and tell you where the file is located. If you use a Windows Operating System, Search is located on your Start Menu. On a Macintosh System, go to the menu bar at the top of your screen and click the magnifying glass. A search box will appear where you can type the name of the file.
TV Programs, like files, have specific lengths. TV shows may be 30 minutes long, 1 hour long, or several hours long. Files are not measured in time, but in bytes. A byte is a measurement of stored data. Larger files may be measured in kilobytes or megabytes. The length of a file tells how much storage space that file is using within the computer.
Questions
Folders or Directories
With so many thousands of files stored inside a computer, it is very important to keep them organized. Folders, also known as Directories, keep files organized by grouping them together. Imagine for a moment that you had a giant toy room filled with toys and you were given the job of organizing all of those toys. You decide to start the job by sorting all of the toys and grouping similar toys together. For example, you put all of your red marbles in a box and all of your blue marbles in another box and all of your clear marbles in a third box. Then, you put all of those boxes into a bigger box and label it “marbles”. Then, you might even put the “marbles” box into a bigger box that contains boxes of “super balls” and “tennis balls” and “baseballs”. You would name that big box “balls”. If you continued to organize toys that way, you would end up with an entire room of boxes with labels that contain similar kinds of toys. Then if you needed to find your plastic brontosaurus, you would know to open the box labeled “toy animals” and go past the “bug box” and the “reptile box” until you find the “dinosaur box” - open it and there is the brontosaurus! In this example, the toys are like files and the boxes are like folders. Your computer is set up to store similar files in specific folders. Then similar folders can be put inside other folders, and so on. Many times, the computer will automatically store files in certain folders in order to keep itself organized. However, when you create new files, you must decide which folders to put them. You can even create new folders to store your files. For example, let’s say that a boy named Adam wants to make a folder of all the fun things he creates on the computer. With an adult’s help, Adam creates a folder titled “Adam”. Within that folder, he creates 3 new folders titled “stories”, “drawings” and “jokes”. Then, when Adam writes a story called “Alien Tap Dancing”, he stores or saves that file that contains the story in the “stories” folder. On a PC, the file name would be “Alien Tap Dancing.txt” because it is a text file. The best way to keep up with a file is to know its address. The address basically tells you what drive and folders to look in for a file. For example, the address for Adam’s story might look like this on a Macintosh system: “Macintosh HD\Users\Adam\stories\Alien Tap Dancing” (Macintosh HD indicates the hard drive). On a PC, the address might look like this: “C:\My Documents\Adam\stories\Alien Tap Dancing.txt”. In this case, the letter “C” indicates the hard drive, as most PCs assign a letter to each drive in the system. Note, that the file address always includes the drive, folder(s), and file name in exactly that order.