INT 10 - VIDEO - GET DISPLAY COMBINATION CODE (PS,VGA/MCGA)

	AX = 1A00h
Return: AL = 1Ah if function was supported
	    BL = active display code (see #00039)
	    BH = alternate display code (see #00039)
Notes:	this function is commonly used to check for the presence of a VGA
	this function is supported on the ATI EGA Wonder with certain
	  undocumented configuration switch settings, even though the EGA
	  Wonder does not support VGA graphics; to distinguish this case,
	  call AX=1C00h with CX nonzero, which the EGA Wonder does not support
SeeAlso: AH=12h/BL=35h,AX=1A01h,AH=1Bh,AH=1Ch,MEM 0040h:008Ah
Index:	installation check;VGA