Tuesday 18 October 2016

Chapter 6 : Understanding Input

What is Input
  • Input is any data instructions entered into the memory of a computer.
  • Instructions can be entered into the computer in the form of programs, commands, and user responses.
An input device is any hardware component that allows users to enter data and instructions into a computer.

The Keyboard
  • A keyboard is an input device that contains keys users press to enter data and instructions into a computer.
  • Most desktop computer keyboards have between 101 and 105 keys, function keys, CTRL keys, ALT keys, and arrow keys. A numeric keypad on the right side of the keyboard.
  • The insertion point is a symbol on the screen that indicates where the next character you type will appear.
  • An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries. Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace.
  • Keyboards on mobile device are smaller and have fewer keys.
Mouse
  • A mouse is a pointing device that fits under your hand comfortably. A mouse can be wired or wireless.
Other Pointing Devices
  • Trackball : is a stationary pointing device with a ball on it top or side.
  • Touchpad : is a small flat rectangular pointing device that is sensitive to pressure and motion.
  • Pointing Stick : is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on a keyboard.
Touch Screens and Touch-Sensitive Pads
  • A touch screen is a touch-sensitive display device
Pen Input
  • With pen input, you touch stylus or digital pen on a flat surface to write, draw, or make selections.
Game Controllers
  • Video games and computer games uses a game controller as the input device that directs movements and actions of on-screen objects such as gamepads, joysticks and wheels, light guns, dance pads, and motion-sensing controllers.
Digital Cameras
  • A digital camera is a mobile device that allows users to take pictures and store them digitally. There are Studio cameras, Field cameras, and Point-and-shoot cameras.
  • Two factors affect the quality of digital camera photos : Resolution - is the number of horizontal and vertical pixels in a display device. Number of bits stored in each pixel - each pixel consists of one or more bits of data. The more bits used to represent a pixel, the more colors and shade of gray that can be represented.
Voice Input
  • Voice input is the process of entering input by speaking into a microphone.
  • Voice recognition is the computer's capability of distinguishing spoken words.
  • Audio input is the process of entering any sound into the computer like : Speech, Music, Sound Effects.
Video Input
  • Video Input is the process of capturing full-motion images and storing them on a computer's storage medium.
  • A Web cam is a type of digital video camera that enables user to : Capture video and still images, Make video telephone calls, and add live images to instant messages.
  • A video conference is a meeting between two or more geographically separated people.
  • Optical character recognition (OCR) involves reading characters from ordinary documents.
  • A turnaround document is a document you return to the company that creates and sends it.
  • A bar code reader, also called a bar code scanner users laser beams to read bar codes.
  • Magnetic stripe card readers read the magnetic stripe on the back of cards such as : Credit cards, Entertainment cards, Bank cards, Other similar cards.

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