Thread: Load .img map onto GPSmap 276C

I have a 276C which I use for motorbike tours – when I started touring it was the only portable waterproof GPS that could do road routing. It also has a very good battery life (I suspect this is a deliberate safety feature for when use in marine or as the same form factor x9x aviation series) compared to modern units something which is a big advantage when renting bikes. I have been given a map as an .img file and cannot find a way of loading it onto my non USB mass storage unit despite looking at forums and using various add on converters. I use a 2012 Apple Mac (not USB3) with BaseCamp (it was all much more simple with MapSource?). I have in the past loaded an OSM map onto my 276 but think I used a Windows laptop and cannot remember the work flow. The map I have been provided is in gmapprom.img which I understand is the unit base map not the supplemental map gmapsupp.img

I have loaded the file as gmapprom.img on SD card in folder called Garmin and BaseCamp recognises it but it is not recognised by the (separate in Mac version) MapInstall nor MapManager. If in MapManager I go File, Install Map the file gmapprom.img is greyed out. I have tried randomly renaming the file gmapsupp.gmap and country.gmap (indicating my level of knowledge!) and in MapManager they are recognised and after clicking Install Map window comes up “Maps installed successfully” but do not show up. My 276C by the way is recognised by BaseCamp and can download tracks from it. If I have to I could use a Windows machine if it is just not on with Mac.

Help please!

I also have a 276C, also as a motorcycle gps, and I would solve your problem with the following methods.
If you are not to use the address search you can split the .img file with gmaptool and the install it to your pc (this is from a windows pc horizon, with Mac your hands are often strapped to your back unfortunately). When installed the map or preferred part of map can be sent to the gps with Mapinstall or Mapsource if it is an older map. Anyway the map can be seen with both Mapsource and Basecamp for the use with route planning and sending routes to the gps.
If the .img file you have can not be seen in Basecamp even when it is in folder garmin in an usb stick the problem cuold be that the flag Ms is not set to 0. This can be made with Gmaptool, write and set flag Ms to 0.
If you can see the map in Basecamp from usb stick (not installed in pc), now fixed with Ms-flag, can you send it directly from Basecamp/Mapinstall? I have not done this so I do not know if it works this way. Then it would be installed in gps with full address search abilities I think.

Sorry for the somewhat unstructured advices, I was just thinking of the possibilties you have. Anyway, the only way I know of how to get maps into the 276C is with the help of Mapinstall or Mapsource. And when sending maps to 276C, use external power in order to avoid problems with corrupt maps.

Thanks Neil for your clarification, I will not have to test that method now...
For me the way I use my 276C it is not a problem with the "split and reload" method since I do not use the search function with the 276C. And anyhow it is very tedious to say the least to enter an address without keyboard so in it is no real drawback. I prepare routes usually with waypoints just after the road junctions and in that way the excellent autozoom function gradually zoomes in to show me where to ride. Tracks can also be used but they cover the road under unless you make a workaround with transparent trackmaps that are typed with double dashed lines that will show the road between the lines. But that is another story.

Neil and Smulan good suggestions and as you say restricted by Mac. I should have bought the Garmin data card reader but now very rare.

Looks like the only way will be to do away with search function and use GMapTool to split the .img file. The Mac version of GMapTool is a terminal so will wait until I can use a Windows machine could you give me a basic description as to what to split the .img file into? Thanks

Not difficult at all to do the split with Gmaptool, a thread of Gmaptool can be found here [Only registered and activated users can see links. ].
Tip: the Sticky threads are really good and well organized, start there when having a question

In short, load the .img file with Files, go to Split and fill in the paths and preferred names and do the split.
Run the install.bat file, as administratror in Win 7 and the map will show up when starting Mapsource or Basecamp.