Virtual Graphics Adapter driver support for reverse resolution.


I have written a virtual graphics adapter driver that consists of -:

- > miniport driver that does nothing except from returning true or

- > display driver is just a skeleton driver that pass all the call to
it to DIB engine through eng calls.

Display driver dll has been written to support the standard resolution
of 800 * 600 . It works well for my extended graphics monitor.

But I want my graphics driver to support the reverse resolution mode of
480 * 800.When in DrvGetmodes i give the resolution as 480 * 800 and
then when I load the graphics driver , the error message flashes that
"this driver has been written for older version of windows..." and the
driver does not get loaded..

Then I tried my graphics driver with ATI card that supports some of
the reverse resolutions. eg 800 * 1200 etc.
So in my graphics drivers DrvGetModes I gave the resolution as 800 *
1200 , and then loaded the graphcis driver.

To my surprise the driver got loaded properly.

Now , I fail to understand why this dependency of my virtual graphics
adapter driver is there on the main ATI graphics adapter.

If this dependency is there , then I can only support resolution that
are supported by the ATI card ?

I want to support resolution of 480 * 800 in my virtual graphics
adapter. If anyone has any idea then please share it .