I didn't see anything on the web site beyond 256, though I know there are 512 cards available, am looking for more than the 32 I got with the legend as I want to get at least the NE corridor from CT to DE loaded for this summer. Currently Western CT and Orlando to Daytona FL has the 32 filled though I don't need the FL part anymore, but also did'nt see any info on memory card mgt, delete maps, memory available, etc... thought I haven't looked in mapsource yet.