Chapter 2 (input & output devices)

Chapter 2 (input & output devices)

1. Input

   • Keyboards
     • Alphanumeric Keyboard : allows text (abc...), numbers (123...) and symbols (%$@...) to be entered into a computer.
     • Numeric Keyboard : only has numbers. Usually can be found in the bank.
     • PIN Pad : numeric keypad, but is used to enter a person's PIN (Personal Identity Number). For example, paying with a credit card.
   • Pointing Devices
     • Mouse : found on most PCs. Sensors on the bottom of the mouse detect when the mouse is moved.
     • Touchpad / Trackpad : found on most laptop. Uses instead of a mouse since it takes up less space.
     • Trackball / Tracker Ball : not moved about like a mouse, instead it has a large ball that the user spins.
     • Touch Screen : the user select items on the screen by touching the surface.
     • Graphics Tablets : often used by designers and artists to allow natural hand movements to be input to graphics applications
     • Joystick / Joypad : used mainly for playing games.
     • Light Pen : used as a pointing device or to "write" on the screen of a computer.
   • Communication Devices
     • Digital Camera : device that captures digital photographs.
     • Video Camera : device that captures moving images or video.
     • Web Cam : used to feed live video into a computer
     • Microphone : device that converts sound into a signal that can be fed into a computer.
   • Card Readers
     • Magnetic Strip Reader : used to read the data from the stripe. (e.g. the credit card number, expiry date, customer name)
     • Chip Reader : data can be stored in this memory and read back using a chip reader.
   • Reading Text / Codes
     • MICR Reader : technology that allows details from bank cheques to be read into a computer quickly and accurately.
     • OMR Scanner : technology that allows the data from a multiple-choice type form to be read quickly and accurately into a computer.
     • OCR Scanner : technology that can convert images of text into an actual text file that can then be edited.
     • Barcode Reader / Scanner : A barcode is simply a numeric code represented as a series of lines.

2. Output

   • Audio / Visual
     • Loudspeaker : If you want to hear music or sounds from your computer, you will have to attach loudspeakers. They convert electrical signals into sound waves.
   • Printing / Plotting
     • Dot Matrix Printer : often use continuous stationary : long, continuous strips of paper. Print quality is poor, the printers are noisy. The dots are formed by tiny pins in the printer's print head that hit an inked ribbon against he paper leaving marks (dots).
     • InkJet Printer : Cheap, high-quality, full colour. This is a close-up of the tiny ink dots on a page. The dots combine to form light and dark areas.
     • Laser Printer : very complex devices, expensive, very cheap to use, very fast printing
     • Plotter : Draw on the paper using a pen, more accurately, more quickly. Only suitable for producing line drawings.