I sent my GPS 276C into Garmin last year for repair. I just recently pulled it out to route some trips. It seems that all my maps are missing?? So,I guess I need to load Mapsource again?? Which leads me to my next problem. All of my computers are Mac now. So, just the facts. Garmin 276C without detailed maps. Apple Computers Desire to map and ride the worst roads in North America Please Help.