The lowrance web site has periodic updates of the software for the HDS chart plotters that you can dwnload onto an SD card, which you plug into the HDS-5 plotter and then turn the unit on. That will update your charts as well as the total software package. The link below takes you to the list of downloads available today. It looks like the most recent updats for the HDS gen-1 saftware was Feb 2012 and the most recent update for the HDS gen-2 was Nov. 2012.