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:
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
|
No comments:
Post a Comment