Map Management
Map files are normally supplied by Garmin along with a Map and GPS management application as a part of their Mapsource software packages. When installed, these packages copy the map and GPS management application and a set of map files onto your PC.
It is possible to persuade the Mapsource management application to upload custom map files in addition to the shipped map files, however, this process seems to be painful and unreliable.
There are a number of other programs which are available to upload maps. The simplest and most reliable of these is the sendmap DOS command-line application. Various Windows front-ends are available which make sendmap significantly easier to use.
Sendmap
The sendmap application allows one or multiple maps (upto the available memory limit) to be uploaded to your GPS. If it is installed in a directory off the top-level of your hard-drive, for example c:\gpsairmap, and the map IMG file(s) that you want to send to the GPS are also in the same folder, then maps can be sent from a command prompt window using the following commands:
cd c:\gpsairmap
sendmap COM2 -p filename.img
You can specify multiple files after the -p option if you want to upload more than one file. Note that each time you send a map IMG file to the GPS, all previous maps are erased, so to upload multiple maps, you must send them all at once using this multiple file facility.
It's possible to make this process a lot simpler by defining a shortcut on the desktop to the sendmap executable, and specifying the necessary parameters in the shortcut properties. Alternatively, the IMG2GPS Windows front-end to sendmap is simpler to configure and use plus it has some other functions that are helpful.
IMG2GPS
The IMG2GPS application allows sets of maps to be easily selected and uploaded to the GPS. The executable file should be placed in the same folder as the sendmap application. The application allows you to browse your hard-drive folders to select a set of Garmin Mapsource and custom maps. Once happy with the set of maps, the upload option transfers them to the GPS (which may take over half and hour, if transferring a large set of maps).
Use the 'Load folder' button to select directories containing map files. The checkboxes on the left of the list of located mapfiles control whether each map will be included in the set of maps to be upload:
Because IMG2GPS shows the map title for all of the map files in the browsed directories, it's easy to select a set of maps and download only those that you need for a particular flying area or wind direction.
Once you've selected a map or set of maps and uploaded them, you can start using the airmap on the GPS...