anchor.diff:  		(setf (point-crs p) (second n)))
   	       ((equal (first n) 'alt)
   		(setf (point-alt p) (second n)))
  +	       ((equal (first n) 'sats)
  +		(setf (point-sats p) (second n)))
  +	       ((equal (first n) 'mode)
  +		(setf (point-mode p) (second n)))
   	       ((equal (first n) 'datum)
   		(setf (point-datum p) (second n)))
   	       ))
  
positive.code:     (list 'datum (point-datum p))
      (list 'alt (point-alt p))
      (list 'spd (point-spd p))
      (list 'crs (point-crs p)))
     (user-info-serialize p)))
  
  (defmethod pp ((p gps-point))
  
negative.code:   (format t "Alt:  ~F~%" (point-alt p))
    (format t "Spd:  ~F~%" (point-spd p))
    (format t "Crs:  ~F~%" (point-crs p))
    (format t "Sats:  ~F~%" (point-sats p))
    (format t "Mode:  ~F~%" (point-mode p))
    (format t "Datum:  ~A~%" (point-datum p)))
  
  (defmethod point-deserialize-method ((p gps-point) point-data)
  