Video Graphics Array(VGA)

This video system was introduced by IBM in 1987.VGA was implemented with VLSI (Very Large Scale Integration) on a single card with 8 bit interface support. VGA is referred to as Array instead of Adapter because it replaced Motorola 6845 and other discrete logic chips that were used in previous video standards. Main Features of this Video Standard are as follows:

a) Analog display output allows display of 16 colors from a palette of 2, 62,144 colors at 640 X 480 resolutions.

b) It was cheap and was backward compatible with MDA, CGA and EGA Cards.

c) It was made up from VGA controller Chip, Frame buffer of size 256/512/1024KB, BIOS Chip and D /A converter along with video process logic.

d) VGA Adapter can handle colored as well as mono chrome display.

e) VGA also provides 26 pin edge connector, known as Video Feature Connector (VFC) to connect ad on video cards o VGA adapter directly.


f) VGA card Uses 15 Pin D shaped Female connector whose pin description is as follows:

Pin No.	Description	Monochrome Use	Color Use
1	Red		Red
2	Green	Monochrome	Green
3	Blue		Blue
4	Monitor ID Bit-2
5	Ground	Self Test	Self Test
6	Red Return	Red Return
7	Green Return	Monochrome Return	Green Return
8	Blue Return	Blue Return
9	Not Used
10	Sync Return	Ground	Ground
11	Monitor ID Bit-0
12	Monitor ID Bit-1
13	Horizontal Sync.	Horizontal Sync.	Horizontal Sync.
14	Vertical Sync.	Vertical Sync.	Vertical Sync.
15	Reserved