VGA

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VGA stands for Video Graphics Array. This term can refer to several different things such as the resolution, the hardware connector, the standard.

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[edit] Resolution

VGA refers specifically to a resolution of 640 x 480 pixels. It implies a screen aspect ratio of 4:3. It may have a prefix to adjust this pixel resolution such as H for half (480 x 320) and Q for quarter (320 x 240). S (super) would up the resolution to 800x600. A W (Wide) prefix changes both the resolution and aspect ratio. WVGA is 800 x 480. The V can also be dropped in favor of another letter. Fore example: XGA (1024x768). See Nomenclature for more details. 2048x1536 is the highest resolution that can be displayed on analog computer monitors (CRT).

[edit] Hardware connector

Female connector

A VGA connector is a DE-15 sometimes called a D Sub-connector. It is the size of a serial port connector but has 15 pins arranged in 3 rows. VGA connectors and cables carry analog component RGBHV (red, green, blue, horizontal sync, vertical sync) video signals on pins 1, 2, 3, 13, 14; and VESA Display Data Channel (VESA DDC) data. Pins 5 and 10 are Ground while pin 9 carries 5V.

[edit] The VGA standard

The standard defines all of the characteristics need to drive the analog video signal to a monitor. It is the minimum standard that is nearly universally available on computer screens. It defines aspect ratio, number of colors, connector, resolution, refresh rate, and signal values. VGA defines 256 color registers, 3×6 bit each for a total of 262,144 colors to chose from but only a total of 256 colors. See above for graphic resolution and connector.

VGA also has a text mode with a typical maximum resolution of 80 characters and 50 lines. The would be 8x8 bitmapped fonts using a 640x400 display. Other displays were also used such as 80x25 character display, rendered with a 9x16 pixel font, with an effective resolution of 720x400 in either 16 colors or monochrome.

Displays as high as 800 x 512 were possible for VGA devices with limited color.

[edit] Converting VGA

VGAtoVideo.jpg

It is possible to convert standard VGA output to video. This simple solution, shown at the right, will work for 60 Hz 640x480 images and perhaps others.

It is also possible to buy conversion adapters to convert from and to VGA.

[edit] For more information

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