upload more than one map on an SD card
I have a Nuvi 250 and I would like to upload multiple map on an SD card using mapsource. I know you can use Mapsource to transfer a map from the PC to a memory card but it look like I'm limited to only one map per card. When I try to upload a second map, it just overwrite the existing one. Is there way to do it so that the gps will be able to read all the map that's on the SD card even if there's 2-3 or more map (img file) in the card?