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 ???