Assurance BCS Digest Book. pdf

3.3. Monochrome or Color

Some monitors display images in only one color, while others are capable of producing images in colors. Monochrome monitors use a single electron beam and display one color, generally green, amber, or white, on a black background. 

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The phosphor composition of the screen determines the color. Color monitors produce multi-color images by combining the red, blue and green colors in varying intensities. Each pixel is made up of three-color dots: red, blue, and green. It will appear to glow in different colors depending on the intensity of each individual dot in the pixel. Color monitors are commonly referred to as RGB monitors since they employ three election beams, one of each color. Color monitors are categorized as CGA, EGA, VGA and SVGA depending on the resolution. CGA monitors provide the least resolution (approximately 300 * 200 Pixels) and SVGA monitors provide the greatest resolution (1000 * 800 pixels and greater) resolution.

3.4. Monitor Interface

A monitor requires an appropriate interface to communicate with a computer. For example, a color graphics interface board is needed for a color monitor. This interface will generally not work with a monochrome monitor and might even damage it. Dozens of monitor interface boards are available for use with microcomputers. A caution must be exercised to match the interface to both the monitor and the computer.

3.5. Using a Television

Some smaller microcomputer systems can be used with a standard television. The basic difference between a monitor and a television set is that the resolution of a television is substantially less than that with a monitor. Also the television requires the use of a modulator to interface the computer output with the television. The modulator combines the separate audio and visual signals sent by the microcomputer into a single modulated signal as required by a television. Most inexpensive computer systems designed for use with a television set generally have a built-in modulator with a standard television. The basic difference between a monitor and television set is that the resolution of a television is substantially less as television set generally have a built-in modulator.