Need access to CRTC registers!

G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

HI, I need to access the CRTC registers on an nvidia card. It's a
SECONDARY card, so it doesnt have the CRTC registers at the usual
$03D4/$03D5 I/O ports. They're somewhere in the MMIO space. This is
on Windows XP.

Anybody have any info on how to get to them?

Code, drivers, API's?


Thanks,

George
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

I need to change the sync pulse widths to be much narrower, like zero
width.
Very easy to do, they're simple CRTC registers.

I already have access to the card's memory area-- I just need to know
exactly where they are in there.
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

Ancient_Hacker wrote:
> HI, I need to access the CRTC registers on an nvidia card. It's a
> SECONDARY card, so it doesnt have the CRTC registers at the usual
> $03D4/$03D5 I/O ports. They're somewhere in the MMIO space. This is
> on Windows XP.
>
> Anybody have any info on how to get to them?
>
> Code, drivers, API's?

What are you doing that needs access to those? Unless you're writing a
kernel driver, you're not going to able to access them anyway, wherever
they are.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

Ancient_Hacker wrote:
> I need to change the sync pulse widths to be much narrower, like zero
> width.
> Very easy to do, they're simple CRTC registers.
>
> I already have access to the card's memory area-- I just need to know
> exactly where they are in there.

I would be rather surprised if that info were publicly available. Your
best bet might be to look at the source code of the "nv" driver used in
the X.org X server in Linux, that MIGHT have some code to access those.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"Ancient_Hacker" <grg2@comcast.net> wrote in message
news:1126457040.903707.316830@g43g2000cwa.googlegroups.com...
> HI, I need to access the CRTC registers on an nvidia card. It's a
> SECONDARY card, so it doesnt have the CRTC registers at the usual
> $03D4/$03D5 I/O ports. They're somewhere in the MMIO space. This is
> on Windows XP.
>
> Anybody have any info on how to get to them?
>
> Code, drivers, API's?

In the Device Manager the resource information shown for each card would be
structured the same; so, given that $03D4 is at a particular offset within
one of the I/O ranges shown for the first card, you then just add that same
offset to its twin I/O range shown for the secondary card.

Tony.
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

The Black Wibble wrote:
> "Ancient_Hacker" <grg2@comcast.net> wrote in message
> news:1126457040.903707.316830@g43g2000cwa.googlegroups.com...
>
>>HI, I need to access the CRTC registers on an nvidia card. It's a
>>SECONDARY card, so it doesnt have the CRTC registers at the usual
>>$03D4/$03D5 I/O ports. They're somewhere in the MMIO space. This is
>>on Windows XP.
>>
>>Anybody have any info on how to get to them?
>>
>>Code, drivers, API's?
>
>
> In the Device Manager the resource information shown for each card would be
> structured the same; so, given that $03D4 is at a particular offset within
> one of the I/O ranges shown for the first card, you then just add that same
> offset to its twin I/O range shown for the secondary card.

It would be a bug in the driver if it was using such resources but not
indicating them in Device Manager - otherwise there is nothing to stop
some other device from trying to use them.

Those registers are basically there for VGA compatibility. There is no
need for a secondary card to use VGA-compatible registers, so those
resources may not be enabled at all.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/
 

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