private void added (DeviceImpl dev)
    {
	if (Linux.trace)
	    System.err.println ("notify add " + dev);

	// call synch'd on devices
	for (int i = 0; i < listeners.size (); i++) {
	    USBListener	listener;
	    listener = (USBListener) listeners.elementAt (i);
	    try { listener.deviceAdded (dev); }
	    catch (Exception e) {
		if (Linux.debug)
		    e.printStackTrace ();
	    }
	}
    }