INT 2F C - Windows 3.x - SWITCHING DOS TO BACKGROUND                            
	AX = 4005h
Notes:	called by Windows when the DOS box is about to be placed in the
	  background and the video driver should save any necessary state
	  information (this may be called only in Standard mode)
	this callout is not made unless the application has first called
	  AX=4000h
SeeAlso: AX=4001h,AX=4006h