Questions about multiple monitors/adapters support

I want to implement a multiple-monitor supported display driver as the
secondary
display driver for Win2k. I downloaded Win2k DDK, but found almost nothing
helpful
there. The only related words are:

****************************************************************************
***
2.16 Multiple-Monitor Support in the Display Driver
Multiple-monitor support is provided by Windows 2000; therefore, display
driver
writers must not implement any special code to provide this support.

Display drivers must be implemented without using global variables. All
state
must exist in the PDEV for a particular display driver. GDI will call
DrvEnablePDEV for every hardware device extension that is created by the
video
miniport driver.


****************************************************************************
***

Does it mean that if I didn’t use global variable in my old display driver,
I
don’t need to modify anything in my old driver to work for multiple monitor?

Thanks,

Questions about multiple monitors/adapters supportI think it is hardly to implement it.
because of the I/O address is overlaped
for the two vga adapters.

any advice is welcome.

Jansen Zhu.
----- Original Message -----
From: Min Wang
To: NT Developers Interest List
Sent: Tuesday, August 29, 2000 2:58 AM
Subject: [ntdev] Questions about multiple monitors/adapters support

I want to implement a multiple-monitor supported display driver as the secondary
display driver for Win2k. I downloaded Win2k DDK, but found almost nothing helpful
there. The only related words are:

*******************************************************************************
2.16 Multiple-Monitor Support in the Display Driver
Multiple-monitor support is provided by Windows 2000; therefore, display driver
writers must not implement any special code to provide this support.

Display drivers must be implemented without using global variables. All state
must exist in the PDEV for a particular display driver. GDI will call
DrvEnablePDEV for every hardware device extension that is created by the video
miniport driver.


*******************************************************************************

Does it mean that if I didn’t use global variable in my old display driver, I
don’t need to modify anything in my old driver to work for multiple monitor?

Thanks,

Questions about multiple monitors/adapters support>Display drivers must be
implemented without using global variables. All state

must exist in the PDEV for a particular display driver. GDI will call
DrvEnablePDEV for every hardware device extension that is created by the
video
miniport driver.

After knowing this, a question arises:

  • why on earth MS implemented such a terrible thing called “session space”
    for the Terminal Server? What was the need of doing this? Why not load
    several display drivers (possibly with several PDEVs each) and link them to
    several WinSta objects in win32k.sys?

Max