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Article: Input Devices
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- Computer Sciences
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CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Input Devices
The work of a computer can be characterized by an input-process-output model in which a program receives input from an input device, performs
some processing on the input, and produces output to an output device. Users employ a variety of input devices to interact with the computer, but most user interfaces today are based upon a keyboard and a mouse pointing input device.
A keyboard consists of a number of switches and a keyboard controller. The keyboard controller is built into the keyboard itself. When a key is pushed, a signal called a scan code is sent to the controller. A different scan code is sent when the key is released. The use of two scan codes allows keys to ...