I have downloaded a couple of poi's & also have one that someone created for me all in .db3 format how can i merge all 3 together to put on my RNS510 as I think I am right in saying you can only put one database on. Also what does the one click update button do? ie does it update the file if you have previously downloaded it?
We have an online software to edit or create a new DB3 file. You can change data format, open and edit your DB3 files here: https://www.gps-data-team.com/convert/
It is often used to load Garmin files to a DB3 GPS models, and to use DB3 files with Garmin GPS models.