Thread: Creating Garmin IMG Maps

Hi Folks,

Can anyone with a GPSMAP share their "best practices" for getting map data onto the GPS? I recently acquired a GPSMAP 62s. I understand all the tools (gmaptool, tkmap, gimgtools, mapsource patched and map install) however there appears still a number of directions one can go in. For instance, I'm running all the tools in a VirtualBox Windows XP session vs native OSX just because there seems to be more support for Windows (including the patched products) available. I have also found that the GPSMap 62s accepts over 4GB of map data as long as maps are in separate .img files, however the total map tile count among all the files needs to be < 4000 tiles. It appears if 4000 tiles is exceeded, the unit does not list the additional maps in the map setup screen. This really made the 32GB flash card I purchased useless. Through trial and error of creating my own .img files < 4000 tiles, I was only able to get the SDHC card to ~9GB.

Now there is the topic of map data. Map data can reside in the form of .gmap files for Basecamp/Mapsource (older format left out for this discussion) and .img files on the SDHC. The SDHC can be accessed inside the device itself via USB cable or placed into the computer's SDHC reader. It appears Basecamp is able to detect and read the SDHC .img map data when it's inserted into a SDHC reader. .img data can be converted to older MapSource (and .gmap with another tool) however in that direction routing information is lost.

Now the issue of map installation. Mapsource patched is good for creating a number of .img files. It allows one to create many .img files so the 4GB FAT32 file limit is overcome, while allowing user to use max 4000 tiles. Mapinstall (at least the Mac version) looks slick, however I"m not exactly sure what it's doing. Mapinstall Mac looks like it had the 4GB FAT32 file limit even though 4000 max tiles were no where near reached.

So how do folks operate efficiently? Here is my takeaways and place correct/comment if you can:

o For the .iso TOPO images (NW, NE, etc..) that get installed as .gmap, those have routing data intact so are a good source
o For .img files pulled from elsewhere (unlocked?) leave those on the device SDHC or some directory and place on device as necessary??
o Mapsource patched Windows is useful for creating .img on local hard disk
o Basecamp is good for KML data overlays. Unsure how to get the data out of this?

Your thoughts appreciated.

Thanks

Also there are a number of .img files with their MS flag == 1. There are mostly TOPOs generated from Garmin data. Can anyone comment on how they use this flag? I'm assuming it should be kept == 1 if the map was generated from data held in your Basecamp/MS and ==0 if Basecamp/MS data is non-existent.

Thanks