It used to be easy. Just select serial port, 4800 baud, on the Triton handheld GPS and plug the Triton into the laptop USB port. But I updated the Triton firmware this week and the connection did not work any more. Apparently the Triton firmware is still under development, as further additions are mentioned by Magellan.
Finally, I selected
USB connection in the Triton menu (instead of serial), set the "baud" to 9600, and NEMA 2.1 format. Now it connects to
Streets & Trips 2006. S&T recognized the USB as COM3 and my position is plotted.
Apparently Triton was released before its manual and firmware were completely developed. If you update your firmware, also download the Triton manual. It is greatly improved, but still lacking some useful information.