Virtual VGA driver

Hi, all:

I have a new task to write a filter driver. This driver will emulate a
virtual VGA card. It can block all commands which send to real VGA card and
emulate those commands on the virtual VGA card, and copy the status of
virtual VGA card to the real VGA card under some circumstances. will it be
working ? thanks.

Leo

It’s going to be a real tough act. For example, you’re going to have to trap IN and OUT instructions. You’re going to have to simulate the sequencer and the CRT controller, the 3c3h and 46e8h config ports, the character generator, and more. You will have to be able to change the layout of your memory, from text mode (4-planes, one character, one attribute, one character generator, one unused) to 4-bit mode (4 planes, one bit per pixel, 16 colors per pixel) to “flat” mode (one byte per pixel, one plane) and maybe more if you want to emulate mode 4 or mode 6. Not to forget that just about every vga chip out there has proprietary i/o ports and functionality that may have to be handled by your model.

But, it can be done, even though it’s tough and it may end up being quite expensive. Are you sure you can’t convince your hw guys to put a vga chip in there ? It’ll cost a lot less.

Alberto.

----- Original Message -----
From: Leo
To: Windows System Software Devs Interest List
Sent: Thursday, December 08, 2005 12:55 AM
Subject: [ntdev] Virtual VGA driver

Hi, all:

I have a new task to write a filter driver. This driver will emulate a virtual VGA card. It can block all commands which send to real VGA card and emulate those commands on the virtual VGA card, and copy the status of virtual VGA card to the real VGA card under some circumstances. will it be working ? thanks.

Leo
— Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256 You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’ To unsubscribe send a blank email to xxxxx@lists.osr.com

Hi

I think what you need is a Mirror Display driver…When you have a mirror display driver attached to the primary desktop then all the rendering calls go the primary display driver as well as the mirror display driver. Mirror display driver would intercept all the calls and can also emulate them… I don’t understand what you mean by transferring the status of virtual vga card to the real vga card…

Mudeem

Alberto Moreira wrote: It’s going to be a real tough act. For example, you’re going to have to trap IN and OUT instructions. You’re going to have to simulate the sequencer and the CRT controller, the 3c3h and 46e8h config ports, the character generator, and more. You will have to be able to change the layout of your memory, from text mode (4-planes, one character, one attribute, one character generator, one unused) to 4-bit mode (4 planes, one bit per pixel, 16 colors per pixel) to “flat” mode (one byte per pixel, one plane) and maybe more if you want to emulate mode 4 or mode 6. Not to forget that just about every vga chip out there has proprietary i/o ports and functionality that may have to be handled by your model.

But, it can be done, even though it’s tough and it may end up being quite expensive. Are you sure you can’t convince your hw guys to put a vga chip in there ? It’ll cost a lot less.

Alberto.

----- Original Message -----
From: Leo
To: Windows System Software Devs Interest List
Sent: Thursday, December 08, 2005 12:55 AM
Subject: [ntdev] Virtual VGA driver

Hi, all:

I have a new task to write a filter driver. This driver will emulate a virtual VGA card. It can block all commands which send to real VGA card and emulate those commands on the virtual VGA card, and copy the status of virtual VGA card to the real VGA card under some circumstances. will it be working ? thanks.

Leo
— Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256 You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’ To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

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thanks Alberto and mudeem.

We have cancled this plan :slight_smile:

On 12/16/05, mudeem siddiqui wrote:
>
> Hi
>
> I think what you need is a Mirror Display driver…When you have a mirror
> display driver attached to the primary desktop then all the rendering calls
> go the primary display driver as well as the mirror display driver. Mirror
> display driver would intercept all the calls and can also emulate them… I
> don’t understand what you mean by transferring the status of virtual vga
> card to the real vga card…
>
> Mudeem
>
> Alberto Moreira wrote:
>
> *It’s going to be a real tough act. For example, you’re going to have to
> trap IN and OUT instructions. You’re going to have to simulate the sequencer
> and the CRT controller, the 3c3h and 46e8h config ports, the character
> generator, and more. You will have to be able to change the layout of your
> memory, from text mode (4-planes, one character, one attribute, one
> character generator, one unused) to 4-bit mode (4 planes, one bit per pixel,
> 16 colors per pixel) to “flat” mode (one byte per pixel, one plane) and
> maybe more if you want to emulate mode 4 or mode 6. Not to forget that just
> about every vga chip out there has proprietary i/o ports and functionality
> that may have to be handled by your model. *
> **
> But, it can be done, even though it’s tough and it may end up being quite
> expensive. Are you sure you can’t convince your hw guys to put a vga chip in
> there ? It’ll cost a lot less.
>

> Alberto.
> **
>
> ----- Original Message -----
> From: Leo
> To: Windows System Software Devs Interest List
> Sent: Thursday, December 08, 2005 12:55 AM
> Subject: [ntdev] Virtual VGA driver
>
>
> Hi, all:
>
> I have a new task to write a filter driver. This driver will emulate a
> virtual VGA card. It can block all commands which send to real VGA card and
> emulate those commands on the virtual VGA card, and copy the status of
> virtual VGA card to the real VGA card under some circumstances. will it be
> working ? thanks.
>
> Leo
> — Questions? First check the Kernel Driver FAQ at
> http://www.osronline.com/article.cfm?id=256 You are currently subscribed
> to ntdev as: unknown lmsubst tag argument: ‘’ To unsubscribe send a blank
> email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the Kernel Driver FAQ at
> http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
>
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> ------------------------------
> Yahoo! Shopping
> Find Great Deals on Holiday Gifts at Yahoo! Shoppinghttp:— Questions? First check the Kernel Driver FAQ at
> http://www.osronline.com/article.cfm?id=256 You are currently subscribed
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> xxxxx@lists.osr.com
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