Thanks for everyones' replies.
Tried MCT brand USB/serial converter but it would not work.
I use a Prolific USB/serial converter to overcome the lack of serial ports. You can use more than one if you want to run more than one GPS based program simultaneously, or you can use a program called GPS gate which allows you to create multiple virtual serial ports so long as you have one serial port or USB/Serial converter bringing the signal into the machine. It actually works.
I am selecting Communications/flight plan upload in the Avmap.
The manual refers to RTE NMEA instructions for uploading/downloadiing routes, but it seems to be the only NMEA instruction not available for selection in the menu.
I want to continue using Oziexplorer at home and in the plane because you can use digitised airservices maps, whereas PC-Planner uses Jeppesen maps, which are already in the GPS.
Using Airservices maps is much better for following VFR lanes and reporting points into Archerfield, for example, which are not shown in the Jeppesen map in the GPS.
The Avmap has one other apparent disadvantage. If you upload all your waypoints and then want to use some of them to create a flightplan via the screen/cursor (very handy), it creates a numbered user waypoint which it overwrites on top of your existing (and selected) already named user waypoint. Very messy and confusing and hard to understand the reasoning, since the machine has already acknowledged the waypoint you have selected.
Waypoints can be added from the database, but it is more cumbersome, and you can't refer to the screen at the same time.
It also has a menu item in the database menu called file manager.
However the manual never mentions it and I can't see how to use it at all.
Any ideas??
The USB port has some strange shaped plug. Probably just as well, because according to their support person in US it is for flashing the main board, not for normal connection to a computer. The manual forgot to mention that info as well.
The problem about uploading routes/flightplans from the computer to the GPS may only be able to be solved by the makers of Oziexplorer including the Avmap parameters in their program so that it becomes a GPS which is recognised by the program. At present it is not a listed type/model.
Might be a job for Ian. The only contact I could find was info@oziexplorer.com.au, and I am not sure if that is current or not.
I have other friends who use Oziexplorer, and it is a real pity Avmap can't interface properly with it at this stage.
Regards
Jeff