The most popular general purpose keyboard used today

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Unformatted text preview: ster I/O devices. INPUT DEVICES An input device is an electromechanical device that accepts data from the outside world and translates them into a form the computer can interpret. A wide range of input devices is available today that can be broadly classified into the following categories: 1. Keyboard devices 2. Point-and-draw devices 3. Data scanning devices 4. Digitizer 5. Electronic cards based devices 6. Voice recognition devices 7. Vision based devices 8. Offline data entry devices The various types of input devices along with their typical applications are described below. Keyboard Devices Keyboard devices are the most commonly used input devices today. They allow data entry into a computer system by pressing a set of keys (labeled buttons), which are neatly mounted on a keyboard connected to the computer system. Keyboard devices can be broadly classified into two types - general-purpose keyboards and special-purpose keyboards. They are described below. General-purpose Keyboards General-purpose keyboards are standard keyboards used with most computer systems. They are called general-purpose because they have enough keys to make them useful for any type of application. That is, they are designed to meet the data entry requirements of a very wide range of computer users. The most popular general-purpose keyboard used today is the 101-keys QWERTY keyboard. It was introduced and promoted by IBM for use with IBM PCs and IBMcompatible PCs (personal computers). It is so called because it has altogether 101 keys out of which the keys for alphanumeric characters follow the commonly used QWERTY layout. The QWERTY layout has been adopted from the standard typewriter keyboard layout. The positioning of the character keys in this layout ensures faster typing speed. In this layout, the alphabetic keys are arranged so that the upper-left row of letters begins with the six letters Q, W, E, R, T, and Y (see Figure 9.2). Designers of other keyboards claim that their boards are easier to learn and use than the QWERTY keyb...
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This document was uploaded on 04/07/2014.

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