This is not a perfect solution but it works. Somehow
You need some tools to get the work done. Look for cgpsmapper, MapSetToolKit and GmapTool. Unpack and install all this tools. Cgpsmapper and GmapTool are command line programs, you need to start them from command line window or from any Norton Commander clone like Total Commander.
I assume that you have Mapsource installed and that your GPS with preinstalled maps is recognised by Windows as a removable drive, for example as drive I:
Begin with creating an empty directory for your map. Put cgpsmapper and gmaptool in this directory and make it current work directory for subsequent commands.
Unpack your map with gmaptool (option is big 'S'):
>gmaptool -S I:\garmin\gmapprom.img
You will get several different files in your work directory. These are maps and additional files for Mapsource. You need to compile preview map:
Now you can use MapSetToolKit. Start it and choose "Install A Existing Mapset". You have to point to tdb file mapset00.tdb, preview file mapset00.img and invent a registry name. Install and your map should be visible in Mapsource.
Do not try to use MDR file generated by GmapTool in Mapsource. This will not work!
You have to unlock map in Mapsource. Simply input 25-character unlock code from your device. This can be found on papers attached to your GPS, on mygarmin.com after registration, in file \garmin\GarminDevice.xml or \garmin\gmapprom.unl or in a file gmaptool00.unl in map directory on your PC.
And as usually: no guarantee, Mapsource may crash, use at your own risk and responsibility.
If Mapsource crashes use MapSetToolKit to remove new map.
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You can make better preview map yourself
GmapTool create very simple basic map, just minimum data to make Mapsource see the map. This is OK for small area map but not good enough for big map like City Navigator. You can improve preview map adding details form basemap.
First get a basemap. This could be file gmapbmap.img form your GPS, free basemap from Garmin:
http://www8.garmin.com/support/download ... sp?id=3645or World Map from Garmin XT Mobile:
http://www.garmin.ru/GarminMobileXTFull.exeNext you will need tools, MapEdit:
http://www.geopainting.com/en/and Personal cGPSmapper 30-day evaluation version:
http://cgpsmapper.com/buy.htmSplit basemap into parts:
>gmaptool -s gmapbmap.img
You will get one or more img files with maps. You can view content of this files with MapEdit (pres Ctrl-0 if you see empty map). For preview choose most detiled map covering required area.
Open choosen file with MapEdit and do:
File->Map Properties->Levels and check levels number, note this for later use. My map has levels 17, 15, 13, 12, 11. Set zoom 7 for last level and then corect other levels zoom to get zoom sequence like 3, 4, 5, 6, 7.
Edit->Select->By Type and select unwanted objects, I recommend selecting all HW-Exits. Close this menu and do Edit->Delete.
File->Save As and save map in polish format .mp.
Open mapset00.mp and do:
File->Map Properties->Levels and make levels and zooms exactly like in basemap. Existing levels should be converted int first and last level and new empty leves inserted in between.
Edit->Select-All objects then right click on an object and select Modify->Extend All Elements up to Level and set last level index minus 1. On my map this is 3.
File->Add and point to basemap saved in mp format. Now your slected objects should be visible on basemap. Use Tools->Trim to select all this elements, right click inside selected area and choose Trim outside.
File->Map Properties and check and correct: on Header tab map ID should be 09999999, on cGPSmapper tab POI Index should be on.
File->Save and save your new map in polish format as mapset00.mp.
Open mapset00.mp in a text editor. This could be very big file, not all editors are capable deal with it. I'm using Notepad2. Look for text like "Region123=" without any name. Correct all empty "=" into "=OTHER".
Run map compilation:
this can take a lot of time, be prepared to wait an hour or more. As a result you will get new mapset00.img that can be added to your mapset in Mapsource.
Personal cGPSmapper can make searchable map. When you use preview map with POI and city index, you will be able to search for places in Mapsource.