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Data Storage Devices

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All programs, pictures, songs, etc are converted into 'files' made up of ... The first microcomputers actually used a cassette player to save files to ... – PowerPoint PPT presentation

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Title: Data Storage Devices


1
Data Storage Devices
  • Use your mouse to click on each slide as you
    advance through the presentation.

2
  • All programs, pictures, songs, etc are converted
    into files made up of millions of zeros and
    ones.
  • These FILES can be moved from one source to
    another.
  • The size of a file is measured in units called
    BYTES.

3
  • There are three common units of measurement for
    files.
  • KILOBYTE a one kilobyte ( 1 KB ) file contains
    approximately 1000 bytes.
  • MEGABYTE approximately 1 million bytes.
  • GIGABYTE approximately 1 billion bytes

4
  • Early files were saved to DATA TAPE.
  • The first microcomputers actually used a cassette
    player to save files to standard cassette tapes.
    This was very slow !!
  • These both used SEQUENTIAL ACCESS techniques to
    get to the data.

5
  • The FLOPPY disk was developed This began the
    age of RANDOM ACCESS devices. ( retrieving data
    from any point on the disk)
  • The first floppy disk was very large and slow.

6
  • As technology improved, data was packed tighter
    on the disk and the RETRIEVAL RATE improved.
  • The Retrieval Rate is a measure of HOW FAST data
    can be pulled from the disk and loaded into the
    computer.
  • The result was the 5 ¼ inch floppy.

7
  • The next big change was the development of the 3
    ½ floppy. It held even more data ( 1.4 mb) and
    had a protective shutter to keep fingerprints
    from destroying data.
  • The shutter opens automatically once the disk is
    inserted into the DRIVE.

8
  • The HARD DRIVE is now found on all computers.
  • It works exactly the same as a floppy but it
    has a metal platter and is sealed.
  • It can hold much more data and the RETRIEVAL RATE
    is much faster.

9
  • The HARD DRIVE is called a PERMANENT storage
    device.
  • REMOVABLE storage devices are those that you can
    easily take with you from one location to
    another.
  • All REMOVABLE devices require both computers to
    have the same DRIVE TYPE.

10
  • The DRIVE is the device that READS the DISK..
  • The DRIVE is installed on the computer.
  • For example If I saved a file on a floppy and
    brought it to your house, you must have a floppy
    DRIVE for me to use it.
  • Floppy drives are being phased out because of
    their low capacity.

11
  • The ZIP Drive
  • Uses a DISK slightly larger than a floppy. Hold
    100 250 mb of data.
  • BUT, you must have a ZIP DRIVE installed on your
    computer(s) to use it.

12
  • CD-R This storage device uses a laser to burn
    dots onto a blank CD.
  • It holds much more data than a floppy disk.
  • Once the data is burned onto the disk, it
    cannot be changed.
  • You must have a CD WRITE DRIVE in your computer
    to do this.

13
  • CD-RW This system did not succeed.
  • It allows the user to REWRITE data to a CD.
  • It was unstable in its early development and
    people did not accept it.
  • You can still purchase and use CD-RW disks IF YOU
    have a CD-REWRITER in your computer.

14
  • CD BizCard
  • A smaller version of the CD-ROM. It will work in
    any CD_ROM DRIVE.
  • They are all different colors AND sizes.

15
  • DVD
  • Similar to the CD
  • Data is burned onto the blank using a DVD
    WRITER ( Burner).
  • They can be read using a DVD PLAYER.
  • They hold HUGE amounts of data
  • Used to store Movies, Video clips, etc.

16
  • SuperDisk
  • Very similar to the ZIP disk
  • Again, you must have a SUPERDISK DRIVE on both
    computers to use a SUPER DISK.

17
  • Other Removable Media
  • SmartMedia Card used in cameras and printers.
    This small device holds 16 mb 1000 mb of data.
  • You must connect a smartmedia READER to your
    computer to use this.

18
  • Flash Memory
  • Also called keychain memory-
  • Has no moving parts. It is similar to the RAM
    inside your computer.
  • These hold 16 mb 1 gb of data. They plug into
    the USB port of your computer.

19
  • As you can see, the evolution of data storage
    devices has moved swiftly.
  • What will tomorrow bring ???
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