Phew. Drauk's interpretation is the correct one! I've just got it, and want to play with on land.
For those who understand these things, my settings for the Garmin are:
attached to COM2
Simulator mode
Aviation In Protocol
The GPSOut ini file is:
Sentences=RMC,GGA,GSA,GSV,RMA,PGRMZ,AV400
Interval=1000
Port=COM2
M (don't know what that's for)
Speed=4800
Thanks