gtmaps.co.nz

Hi Gary
I sent from Mapsource the Open GPS NZ Autorouting to my Garmin Vista HCX. When I went to use my Garmin, the Topo maps previously there were gone. I then sent from Mapsource to the Garmin the Topo maps however the Open GPS NZ Autorouting was now gone. Looking into Mapsource I can find the validation box (drop down) which says Open GPS NZ Autorouting but there is now no Autorouting file anymore. Is Mapsource overwriting the files? Do I need two mini SD cards, one for Autorouting and one for the Topos and interchange when I need each one?
Thanks
Nick

Yes - it does overwrite whatever is on the card each time you write maps to it.
There is no problem with putting both in at the same time - it's just that doing it is one of those non-intuitive things. You need to select NZ Topo, select all the maps, THEN switch the product to the Autorouting maps, select them, THEN send all the maps at once.
You can of course put them on separate cards if you like.

Hi guys.
I run the Autorouting maps and GT Topo maps on my Vista HCx. Both mapsets update independently on my computer and auto-instal to an appropriate directory. Using Mapsource I can then switch between autorouting & topo as often as I need to. For the GPS I then select ALL tiles from each mapset that I want on the GPS and load them in the same transfer. (Like you Nicklev, I got caught with overwriting wanted maps on the GPS the first time I tried but the process is now quite straight-forward doing them all together. ) How do you like the HCx Nicklev -- I'm rapt with mine!

An old thread, but bumping it in case someone else is on the same track.
Apart from the tried-and-true method to combine maps explained by Gary, there is one very fast method that has other benefits. (This is for the older Garmin GPS models that only accept one gmapsupp.img file.)

1. In Mapsource, you export each individual map to the card, one at a time. So for instance you export GTMaps. On the unit, this creates a file called Garmin/gmapsupp.img. You rename it GTMaps.img and copy it to your hard drive. Delete the file from the unit. [Note that this step is not strictly necessary as Gary's CD already comes with a gmapsupp.img file. Just copy it to a working folder and rename it as above.] Then export the Free Open GPS map to the unit. Again, this creates a file called Garmin/gmapsupp.img. Rename it something like FreeNZ-111014.img (the numbers are for you to remember the the map version: here 2011 October 14) and move it to your hard drive.
2. Using GMaptool (a free program made by a Polish programmer), you can join the two img files in a few seconds. (For detailed instructions on how to do that click my signature and search the page for GMapTool.) Once the files are joined into a new map, rename it to gmapsupp.img, and move it to the card under the Garmin folder (very important). You could do this to combine any number of (renamed) gmapsupp.img files, subject to your device's tile limits.

A key benefit of this method is that if you want to change just one part of your big map file (for instance, the Free Open GPS map that updates all the time), you don't need to export both mapsets again. You already have the GTMaps.img file (which won't change as often), all you need to do is export the new FreeNZ map, which is quite fast, and glue the two img files together again.

Great suggestion. Thanks Andy.