Input/Output Devices
An input device is something you connect to a computer that sends information into the computer. An output device is something you connect to a computer that has information sent to it
Input
⋆ The computer receives information from input devices.
Input devices consist of the camera, scanner, keyboar, mouse, track ball, joystick, microphone, touch screen, web cam.They all send information to the computer. Input devices can be categorized based on:
- modality of input (mechanical motion, audio, visual, etc.)
- whether the input is discrete (pressing of key) or continuous (a mouse’s position, though digitized into a discrete quantity, is fast enough to be considered continuous)
- the number of degrees of freedom involved
Output
The computer sends information from output devices. Output is simply
anything the computer produces. The stuff displayed on the monitor is output, sound is output, and the pages the computer prints are output.
Output devices consist of the webcam, monitor, printer, headphone, screen projector and etc.
Both at once
Some devices can do both input and output. For example, a hard drive can supply input to the computer as well as store output. A modem both sends and receives information.
The computer sits between the input and output devices. A computer program processes and digitises the input information. The result is then sent to an output device such as a screen.
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