I am newer than a newbie to my Macbook air osx 10.9.3. I have used Map Source on windows for years to download maps into my GPSMAP 60CS. The Mac will not work with the old cd. I stumbled upon and downloaded the Basecamp from Garmin Ver. 4.3.1 onto my Mac. I have been able to transfer all my waypoints from the gps into Basecamp. I have been able to run a route locally and transfer it into Basecamp on the Mac as well. The Basecamp base map is fine for looking at, but I would like to have more details in the map. This being an older gps unit, it does not have an SD card so I had to select map units from Map Source to stay within the memory limits.
I was going to purchase some maps from Garmin then I stumbled across the Open Source Maps. I have successfully downloaded some states onto the Mac. I was expecting the download to be transferred automatically into Basecamp. It did not happen. My problem is how to get the downloads into Base camp. I have spent time searching the forums for this step but have yet to find it. The links that go to the Wiki site are informative but I am a computer user and know nothing about programming.
Any assistance would be greatly appreciated.