INT 15 - HUNTER 16 - AUTHORISE CHARGING                                         
	AH = 65h
	AL = charging level
	    01h charging not allowed
	    02h charging allowed until power down
	    03h charging allowed until batteries changed or fail.
		Ask user if charging is still allowed on next poweron
	    04h charging allowed indefinitely
	BX = 0203h
	CX = 0405h
	DX = 0607h
Return: AH = status
SeeAlso: AH=66h,AH=68h