INT 2F - Windows 3+ (OS/2 2.x???) - GET VIRTUAL DEVICE DRIVER (VDD) CAPABILTIES
	AX = 4000h
Return: AL = video virtualization (see #02746)
Notes:	This function is used by display drivers to find out what capabilities
	  exist for the VDD driver and also trigger the VDD driver to call
	  functions 4005h and 4006h (and 4001h/4002h under OS/2?).  This
	  function also gives the Video Driver hardware access to the video
	  registers.
	Once the background/foreground callouts have been activated by a
	  call to this function, the application *must* handle those callouts
	  and save/restore the video memory itself.


(Table 02746)
Values for Windows video virtualization:
 01h	does not virtualize video access
 02h	virtualizes the video when in text mode
 03h	virtualizes the video when in text mode or single plane graphics modes
 04h	virtualizes the video when in text mode, single plane graphics modes,
	  and VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. multiplane modes
 FFh	virtualizes the video fully