I might be wrong but, there is one thing I am kind of wondering about. I have an Earthmate too but I am sorry to say it does not use the NMEA 0183 format but rather a proprietary one (well yeah, not what most GPS receivers seem to output). From their FAQ :


Earthmate outputs Rockwell binary protocol and was designed specifically to work with DeLorme mapping software only (Street Atlas USA® 6.0, 7.0 and 8.0; Street Atlas USA Road Warrior Edition; Topo USA® 1.0, 2.0, and 3.0; AAA Map'n'Go® 5.0, 6.0 and 7.0; 3-D TopoQuads®; Golf Digest Places to Play Travel Planner; Topo USA: Fly-Fishing Edition; Eartha Global Explorer®; and Solus® Pro software). With a free update, Earthmate also works with Street Atlas USA 5.0, AAA Map'n'Go 4.0 and GPS MapKit®.


Not quite sure if there is any information on this Rockwell protocol but it is one thing to bear in mind if you go out to buy GPS enabled software and receivers.

I also have a Garmin GPS35PC and that outputs some fairly easy to interpret messages in the NMEA 0183 format (with some Garmin extentions for controlling extra features). From a programming point of view that is.

Defenitly something that would have to be taken into account in any nav-project.

Hans

Mk2 - Blue - 080000431