Using GMapTool to combine multiple maps into one mapset file for Garmin GPS

We mentioned earlier that Garmin GPS navigator supports several mapset files. That should be enough for normal users.

Saving different map into different mapset file also makes it easy to replace the map to newer version in the future, as well as convenient to remove a single map from the GPS storage.

However, if you have a lot of map that you want to load into your GPS, or you want to store all the maps into SD card which supports only a single gmapsupp.img in it, you might need to combine (join) the maps into one mapset file by using specific software tool. GMapTool is one of the powerful tool which allow you to join and/or split maps in mapset file.

You can visit this webpage to download GMapTool. It supports multiple platform:

• Windows - GUI and command line
• Linux - command line
• Mac OS X - command line
  
  
  

By using the GUI interface of GMapTool, it is pretty simple to combine the mapsets.

Firstly, store all the mapset files you wish to combine in different filename in your PC. It is recommended to store them in the same folder/directory.

Under the Files section of GMapTool, select the maps you want to combine by clicking on Add Files (to select one file at one time) or Add Directories (to select all *.img files in the directory). Note that you can always remove any file in the listing by selecting it and press the Delete button of your keyboard.

When you are done with the mapset selection, continue to the Join section.

Specify the Output File, and key-in the Mapset name of your file to be created. This mapset name will be displayed under each of the map name when you list your maps in Map Info function of your Garmin GPS.

Click the Join all button, and the combined mapset will be created. You can then copy the new mapset file to your Garmin's internal storage or SD card.

Note that if any of the maps in your mapset file is locked by vendor, you still need the 25 bytes unlock key stored in a *.unl file in the same folder and with the same name as the mapset file where the locked map is stored in. To unlock 2 maps inside the mapset file, put both the keys inside the *.unl file one after another, without space (the file size will be 50 bytes then).

To get rid of the hassle, you might want to use another tool called Garmin Unlocker to permanently unlock the maps before combining them with GMapTool.

You might probably be interested to also read about:

• Using GMapTool with cGPSmapper to convert finalized gmapsupp.img back to MapSource maps
• Fixed GMapTool problem regarding "Multiple products in img, creating TDB aborted"