INT 21 - DR DOS 5.0+ internal - GET POINTER TO INTERNAL VARIABLE TABLE

	AX = 4458h
Return: ES:BX -> internal variable table (see #01584,#01585)
	AX = ??? (0B50h for DR DOS 5.0, 0A56h for DR DOS 6.0, 0FE4h for
		  Novell DOS 7)
SeeAlso: AX=4452h