Input Devices (Made by Karl Taylor)

Input Devices (Made by Karl Taylor)

1. How images are transmitted

   • Bars on bar codes are taken in pairs and can stand for numbers which when put together can make a code which stands for something
   • When you shine a laser at the bar the difference in light reflection between the light and dark is information that the computer uses
   • Images are stored in a grid of small squares which are given the value 1 or 0
     • The image can become clearer by increasing the number of squares (pixels)
     • Increasing the max value of the squares from 1 to 2 allows for more shades
       • 00 = white
       • 01 = light grey
       • 10 = dark grey
       • 11 = black
     • Colour requires each pixel to have a combination of 3 colours: red, green and blue

2. Keyboard

   • Contains a number of characters with each key responding to a number of 1s and 0s that identify the key that has been pressed

3. Mouse

   • Can be wired or wireless
     • Privacy issues with wireless
       • Difficult to make the information go to only one user
   • Devices that are connected to the computer by a cable are hard wired
     • Types of wiring
       • Simple copper cable
       • Optic fibre cable (uses light rather than electricity)

4. Touch Screen

   • Output Devices
   • Easy to use because user just needs to point at the screen
   • Largely vandal proof because it can be exposed to the elements in places such as train stations
     • Easy source of information specific to the area
   • Is an output and input device
     • User inputs then receives the output on the screen

5. Microphone

   • Collects sound and inputs it into a system
     • Can collect noises as well as voices
   • Used by car alarms
     • Sets of the alarm when it hears the sound of glass breaking

Images and files in the map