I have a base model Garmin Etrex, and am considering buying a cable to link it to my PC, What I am wondering is what data I can get out of it.

The manual says that it outputs posn and velocity in NMEA or ASCII format, but it does not make it clear if this is historical data or real time data. If it is historical data i.e. how often does it store this i.e. every second every 30secs etc.

does anyone have any experience of this, or can reccomend some software.