INT 10 - VIDEO - DESQview 2.0x only - internal - SET ??? HANDLER

	AH = 80h
	DX = 4456h ('DV')
	ES:DI -> FAR subroutine to be called on ???
Return: DS = segment of DESQview data structure for video buffer
Note:	this function is probably meant for internal use only, due to the magic
	  value required in DX
	the subroutine seems to be called when the DESQview menu is accessed;
	  on entry, AL = 03h or 04h