Garmin GPS - How to Load OpenStreetMap (OSM) Maps in your GPS

This post is about loading the UK OSM maps in my Garmin etrex VISTA HCx GPS device on the microSD card.

These maps are a lot better than the ones that came in my GPS, and they're free. So:

1. Go to http://talkytoaster.info/ukmaps.htm, this website provides the OSM UK maps both for your GPS and the for the software application  you  might  have on your computer: MapSource or Basecamp.

The  website's main page will give you the general overview -following that, read their FAQ page for important and step by step instructions (covers various Garmin GPS models).

2. I assume you have now understood you need a specific map file for your GPS (and it's not the same with the map file you'll be using with the software application on your computer). So try to download the correct .zip file.

This is the one I've downloaded:

OS 1:50K Look and Feel Mapset For Use With Garmin GPSrs Only - Routable+Contours
File Name:	Size: Unzipped	Description:	Download Link:
121228-British-Isles+Contours-Routable-OS50tt-GMAPSUPP.zip contains 121228-British-Isles+Contours-Routable-OS50tt-GMAPSUPP.IMG	~540 MB	British Isles Map (With Contours) - Routable. Can be overlaid over other maps.	HTTP:121228-British-Isles+Contours-Routable-OS50tt-GMAPSUPP.zip Torrent:121228-British-Isles+Contours-Routable-OS50tt-GMAPSUPP.zip.torrent

The HTTP link stoped a number of times with me, and you can not resume downloading, so I ended up installing the Torrent client and the download was straight forward, just click on the 'torrent' link. You'll download a .zip file.

3. Unzip this archive .zip file. Rename the map file '121228-British-Isles+Contours-Routable-OS50tt-GMAPSUPP.IMG' to GMAPSUPP.IMG. (your original file name might be slightly different).

The easiest way to do this is to Right click on the file, select Properties, highlight the text prefixed to 'GMAPSUPP.IMG' and delete it.

4. Create a folder called 'GARMIN' on the microSD card and copy the 'GMAPSUPP.IMG' in this folder.
(The path looks like 'I:\GARMIN\GMAPSUPP.IMG' in Explorer on my computer, your drive letter might be different)

5. Insert the SD card in the GPS device, the map will be picked up automatically.

6. Make a donation to talkytoaster on their website !