INT 10 - VIDEO - XGA - GET DMQS (Display Mode Query and Set) DATA LENGTH

	AX = 1F00h
Return: AL = 1Fh if supported
	    BX = number of bytes of DMQS data
Note:	not supported on the original IBM XGA, only on XGA-NI (non-interlaced)
	  and later models.
SeeAlso: AX=1F01h