VGA specifications ,where ?

[Yves Houbion]

I need to know the timing of a 640 X 480 VGA signal. I want to build a
very little pattern generator to repair monitors. I did it some years ago but
for the new microprocessor based monitors my generator doesn't have enough
precision.

Greetings,
Yves

[Tomi Holger Engdahl]

You cna find VGA card timing details I have collected at
http://www.hut.fi/Misc/Electronics/docs/pc/vga_timing.html

--
Tomi Engdahl (tomi.e...@iki.fi, http://www.iki.fi/then/)
I maintain electronics and PC hardware web pages at
http://www.hut.fi/Misc/Electronics/

[Jeroen Stessen]

Yves Houbion <yves.h...@fundp.ac.be> wrote:
> I need to know the timing of a 640 X 480 VGA signal. I want to build a
> very little pattern generator to repair monitors. I did it some years ago but
> for the new microprocessor based monitors my generator doesn't have enough
> precision.

Hello Yves, here it goes:

"VGA industry standard"
Clock frequency 25.175 MHz
Line frequency 31469 Hz
Field frequency 59.94 Hz

One line:
8 pixels front porch
96 pixels horizontal sync
40 pixels back porch
8 pixels left border
640 pixels video
8 pixels right border
---
800 pixels total per line

One field:
2 lines front porch
2 lines vertical sync
25 lines back porch
8 lines top border
480 lines video
8 lines bottom border
---
525 lines total per field

Sync polarity: H negative, V negative
Scan type: non interlaced.

Good luck,
Jeroen.

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