INT 2F U - DOS 3.0+ internal - GET ADDRESS OF SYSTEM FILE TABLE ENTRY           
	AX = 1216h
	BX = system file table entry number
Return: CF clear if successful
	    ES:DI -> system file table entry
	    BX = relative entry number in system file table containing entry
	    AX destroyed
	CF set if BX greater than FILES=
Note:	supported by DR DOS 5+
SeeAlso: AX=1220h