AT5 maps generated via the IMC always have the same name, large.at5, so you can only have one of them in the same location on a disk/memory card. What you can do is just change the name once the file has been generated, so that when you generate another map it will not be overwritten. Another option is to put your maps into separate folders on the memory card - the unit will find them. e.g. create a folder for each map, and specify this folder as the destination (not the root of the drive) when exporting from RM.
