Input Devices

Input Devices

1. Keyboard: most common and widely used.

   • Keys: Alphabet keys, Function/ F keys (F3), Numeric keys, Arrow keys and Command keys (insert,delete)
   • 'QWERTY'
   • Using for too long can lead to health problems - repetitive strain injury (RSI)
     • Ergonomic keyboard has been created - hands in more natural position

2. A piece of hardware used to enter data into a computer

   • Manual input devices
   • Automatic input devices

3. Mouse: 'pointing device' enables you to control what happens (pointing, clicking, selecting items).

   • Two buttons and central wheel (scroll).
     • Left button: choose menu item
     • Right button: brings up list of relevant menu items
   • Advantages:
     • Ideal for use with desktop computers
       • Supplied as part of new computer system
         • Most familiar with them - little training
           • Works well in conjunction with keyboard for data entry
   • Disadvantages:
     • Need flat space close to computer
       • Rollers can become clogged with grease
         • Overuse can lead to RSI

4. Touchpad: input device usually found on a laptop. Used in place of a mouse.

   • Advantages:
     • Useful for laptops when using a mouse isn't practical
       • Pads position is fixed
         • Very short finger movements needed to move cursor
   • Disadvantages:
     • Takes practice and skill to control position of cursor
       • Gloves cannot be worn
         • Moist and sweaty fingers can disrupt signals picked up the the sensors

5. Joystick: originally used by pilots -> computer games (more realistic). Move in many directions. Controls machines such as cranes, trucks

   • Advantages:
     • Better gaming experience
   • Disadvantages:
     • Some people may find them more difficult to control
       • Not particularly robust, can break easily

6. Concept keyboard: contains grid of buttons that can be programmed to do whatever you want (can use symbols). Usually for when fast input is needed i.e. Fast food restaurant.

   • Advantages:
     • Much faster for making non-text selections (menu)
       • Waterproof - useful when risk of dirt and splashes
   • Disadvantages:
     • Poor for text/numeric input. (some do have numeric keypad to show amount sold)
       • Limited to options shown on keyboard

7. Touchscreen: only device that works as both an input and output device. View options on screen (output) then use your finger to touch option (input).

   • Advantages:
     • Easy to use, not much training
       • No extra peripherals i.e mouse are needed
   • Disadvantages:
     • Not suitable for inputting large amount of data
       • Not robust, can soon become faulty

8. Scanner: convert images/ text on paper into digital format. Shines beam of light then sensor detects colour that is reflected back and builds up image this way. (Flatbed and Handheld)

   • Advantages:
     • Accurate and reasonably high quality
       • Images can be enhanced once digitalised
   • Disadvantages:
     • Take up a lot of memory space
       • Lose some quality

9. Graphics tablet: Designer can produce more accurate drawings than they would with a mouse. Sensitive tip to have heavier or lighter lines

   • Disadvantages:
     • More expensive than mouse
       • Not suitable for general selection work
   • Advantages:
     • Natural to draw with pen than mouse
       • Great level of accuracy can be achieved

10. Magnetic Ink Character Recognition: Banks process cheques 300 per minute, 100% accuracy this way.

    • Advantages:
      • Quick and very accurate
    • Disadvantages:
      • Reader and Ink are very expensive

11. Optical Mark Reader: detect pencil by reflecting light (less light where the mark is). Sends results to computer (storage, analysis and reporting).

    • Advantages:
      • Fast for inputting large amounts of data
        • Much more accurate than humans
    • Disadvantages:
      • May not be read correctly
        • Not suitable for text

12. Optical Character Recognition: normal scanner and specialist software changes the letters into a form that can be edited/ processed by a word processor

    • Advantages:
      • Cheaper than paying someone manually
        • Much faster
    • Disadvantages:
      • Not 100% accurate
        • Documents need to be checked over

13. Magnetic strip reader: back of credit cards, loyalty cards.. It can hold personal details (60 characters). Swiped through magnetic strip reader machine - info fed top computer

    • Advantages:
      • Simple to use
        • Cheap to produce
    • Disadvantages:
      • Limited storage capacity
        • Data destroyed by strong magnetic fields

14. Barcode Reader: series of vertical bars - give information on country of manufacture, name of manufacturer, product code. Automatic input device

    • Advantage:
      • Any price change only needs to be made to the database and not the packaging

15. Biometric Devices: Fingerprint and retinal identification, facial recognition. UK passport - microchip. But also ATMs, registration.