INT 2F U - DOS 4+ XMA2EMS.SYS extension internal - GET HIDDEN FRAME INFORMATION 
	AH = 1Bh
	AL <> 00h
	DI = hidden physical page number
Return: AX = FFFFh if failed (no such hidden page)
	AX = 0000h if OK, then
	    ES = segment of page frame
	    DI = physical page number
Notes:	this corresponds to the data edited out of the INT 67/AH=58h call
	FASTOPEN makes this call with AL = FFh
SeeAlso: AX=1B00h