As all-in-one gps units are still quite expensive
(at least 200 euro) I want to connect a gps-mouse (which will cost less
than 100 €) to the ti-89 which should then display for example the location,
ground speed and direction of movement. Also in this way I can
decide by myself what I want to do with the data, for example I would like
to use the ti-89 for waypoint tracking.