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Unformatted text preview: ard or a video card) in the main computer box
and connecting it to the appropriate monitor. The four most popular of these standards
- CGA (Color Graphics Adapter). It has a low resolution of 320 x 200 and supports up
to 16 colors.
- EGA (Extended Graphics Adapter). It has a resolution of 640 * 350 and supports up
to 16 colors.
- VGA (Video Graphics Array). It has a resolution of 640 x 480 and supports up to 256
- Super VGA. It provides resolution from 800 x 600 to 1280 x 1024 and supports 256
or more colors.
Today, CGA and EGA are standards of the past because all modern personal computers
come with at least VGA output.
A video card (graphics adaptor card) has its own memory called video RAM. The higher
the resolution and the more colors a monitor supports, the larger is the video RAM
required. The video RAM capacity required for different types of monitors is summarized
in Figure 9.22. Flat Panel Monitors
A flat panel monitor (shown in Figure 9.23) is only about one inch thick, is light in
weight, and consumes less electricity as compared to a CRT monitor. These features
make a flat panel monitor most suitable for use with portable computer systems such as a
laptop (notebook) computer. Note that a portable computer must be compact in size, light
in weight, and should consume less power so that it can be operated for longer durations
with batten at places where there is no power point, such as while traveling. These
requirements render a CRT monitor unsuitable for these systems because of its large size,
heavy weight, and more power requirement.
The display technologies used by flat panel monitors include liquid-crystal display
(LCD), electro-luminescent display (ELD), and gas-plasma display (GPD). Out of these,
LCD monitors are most commonly used. As the name implies, LCD monitors use a
special kind of liquid crystals to display images on the screen. The liquid crystals used in
these monitors are normally transparent, but become opaque when charged with
One problem with these monitors is that they are hard to read und...
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This document was uploaded on 04/07/2014.
- Spring '14