multiple monitor compliant W2000 graphics driver

[Ivor Bowden]

Hi, I hope this is the right group to post this question, if there is
a better one please let me know, thanks. I am working with a
programmer on a graphics driver that we wish to be compatible with
other graphics cards in the same system. This programmer says that all
IO must be converted to the alternate memory mapped space; I think
that it is sufficient that the standard VGA IO space can be moved or
disabled.

What other issues, if any, need to be addressed? Is there any type of
"How can I make my driver multiple monitor compliant" or similar
document / url? Thank you!

The only thing I can find about this from Microsoft is this: "Windows
2000 provide multiple-monitor support, so display driver writers must
not implement any special code to provide this suppport. Display
drivers must be implemented without using global variables. All state
must exist in the PDEV for a particular display driver. GDI calls
DrvEnablePDEV for every hardware device extension that is created by
the video miniport driver. To track window changes in a
multiple-monitor system, a driver can ask DGI to create WNDOBJ objects
with desktop coordinates. The driver does this by calling EngCreateWnd
using the flag WO_RGN_DESKTOP_CORD. See Tracking Window Changes for
more information. In a multiple-monitor system, GDI stores the
device's desktop position in the dmPosition memeber of the DEVMODEW
structure."