Conneect your Magellan Explorist 400™ to your computer. Choose menu->advanced->communications->file transfer->internal memory. The contents of the device's memory will show up as a mounted disk on your computer. The directory (folder) is 'Background Maps' and the file you need to save is 'BASEMAP.MGI'.

Windows users may have to explictly enable showing hidden and system files to see it.

These products have not seen a lot of updates and Magellan is pretty stingy with information on the various versions. (If you have the version numbers here, please do use the link at the bottom of the page to provide those.)

2.03 (Dec 2005): an update that corrected a lockup on invalid maps. If you were lucky and the map was on a card, you could remove the card to boot it; if you were not lucky, you had to RMA the unit. Added ability to mark geocaches as found.

2.57 (March 2007): Added back some of the navigation screens (large print, "six fields" screen, "road view" screen, from Meridian, waypoint projection. Note that this version was released only for the European and Australian users, though some North America users report success with it. For the Explorist 210, this version was apparently called "2.53".

Magellan has been very scant with firmware updates on this product line. As mentioned above, 2.57 was only released for the European and Australian models. Some U.S. users report success upgrading their models; others silently ignore the upgrade attempt or just quit working. There have been attempts to correlate success with serial numbers, but the results are inconclusive.

Between the guarantee that WAAS will no longer work, the reality that the newest firmware isn't available for products sold into all countries, and the oddities of some units rejecting or even "bricking" during a firmware update, it's difficult to recommend the process.