how do you veiw the gmapsupp.img on basecamp
What map are you using? Most of the maps from here include an installer that places the data on your computer where Basecamp will show it. Maps installed on your computer are in a different format from gmapsupp.img.
If you purchased a map from Garmin that was pre-installed on a memory card, or if you have a GPS like the Montana 650t that has a pre-loaded topo, connect it to your computer and open Basecamp. It should detect the map and access it directly over USB. If that doesn't work, I believe JDM will let you set a flag to make the map work in Basecamp
http://www.javawa.nl/jdm_en.html
If you tell us which map you're using and where you got it, we can probably be more helpful.
i bought it used i never got nothing with it
What model GPS? What is the map? If you look in the map settings under map info (on most models), you should see the name of the map.
Try connecting it to your computer and run Basecamp. Does it "see" the map?
i have Garmin 220 hand held its says i have Garmin TOPO U.S. 100K v.5
If you plug the gps into your computer, BaseCamp should display a factory installed map. Works that way on my Montana 650t.