Check out the seatalk module
http://www.marinecomputing.com/products/nmeaseatalk/
This will get you started.
Shane.

"Steve Zweigart" wrote in message
...
Has anyone attempted to connect their GPS unit to more than one
"listener", e.g. DCS radio, autopilot, laptop, radar, etc? If so, how
was it done? With hardware "expander"? Interested in any experiences.