Page 59 - DCAP101_BASIC_COMPUTER_SKILLS

Basic Computer Skills

Notes • Digitizer

• Electronic cards based devices
• Speech recognition devices
• Vision based devices

Various types of input devices along with their applications are described below.
4.2.1.1 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) neatly mounted on a
keyboard connected to a computer system. The popular keyboard used today is the 101-keys
QWERTY keyboard.

Figure 4.6: The Layout of Keys on a QWERTY Keyboard

4.2.1.2 Point and Draw Device

Interaction with computers was initially restricted mainly to text mode. However, it was
soon realized that interacting with computers in text-mode is cumbersome and time-
consuming. Hence, a new type of user interface called graphical user interface (GUI), was
devised for interacting with computers. A GUI provides a screen with icons (small images
on the screen) or menus and allows a user to make rapid selections from them to give
instructions to a computer. For efficient utilization, OUI requires an input device that can
be used rapidly point to and select a graphic icon or menu item from the multiple options
displayed on the screen. The keyboard though usable, was found to be inconvenient and
unsuitable for this requirement. Hence, research efforts to find a suitable input device to
meet this requirement gave birth to several input devices like mouse, track ball, joystick,
light pen, and touch screen. Later it was realized that many of these devices, like mouse
and light pen, could also be used very effectively to create graphic elements on the screen
such as lines, curves, and freehand shapes. With this new ability, these devices came to be
known as point-and-draw devices. These input devices have made computers a much more
easily usable tool establishing them as a versatile tool for a wide range of users including
children, illiterate citizens, and graphic designers. Some commonly used point-and-draw
devices are described below.

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