New owner of a Dakota 20. I discovered this great website and loaded MO Topo and My Trails into BaseCamp then onto a card and everything worked fine. I then loaded the IL Topo and WY Topo into Basecamp and onto the Card. When I fired up the Dakota again the only map available was the IL Topo which was the last one I loaded onto the 16 GB micro SD. Would appear each time I load a map it overrides the existing map. Assume I am doing something wrong and would appreciate some help.
Are you using a card reader?
BaseCamp (actually MapInstall, which is a program called by BaseCamp) assumes that on SD there could be only single file \Garmin\gmapsupp.img. It overwrites this file each time you send a map to SD on card reader. Solution is to rename gmapsupp.img to something other, preserving extension *.img. Alternatively you can mark all maps you need in BaseCamp/MapInstall and then you will get all maps sent in a single file.
I think Garmin expect that you send maps directly to Dakota with SD inside. In this case transfer would be very slow, but BaseCamp/MapInstall would take care to not overwrite maps and to give for each file a meaningful name.
Yes I was using a card reader. I will try to connect the GPS directly to the computer and see if that works. Thanks.