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Dakota 20 Custom maps

Started by harlikwin, February 14, 2018, 12:23:28 PM

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So I've run into an issue with my previously owned Dakota20.

I've downloaded various state level maps to base camp, and it can upload them to Dakota.
Problem is that the dakota doesn't "see" them with the normal names. i.e. cotopo11.img. IF I rename the map to say gmapsupp.img then it will see it. Additionally the unit came with a bunch of other .img files which are a string of numbers, again if I rename the file to one of those EXACT number strings, it will see those maps. However this limits me to only "filenames" I have ~10 or so, and I'm trying to load the whole US on the 16gb SD card (plenty of room, just run out of filenames)

From my understanding it "should" be able to read any filename and just load it.
I've looked at the system XML file and it "looks" like it will read img files.

Also there is cgpsmapper file/map, which I understand is an older program for loading files onto the dakota. Maybe this is causing the issue?

I've got the version 5.8 software on it and GPS software 5.0

I tried clearing/updating it when I got it but it has the CGSmapper stuff in the "about" section as well as bizarely named maps from the UK when the unit is recognized in basecamp.

If anyone can help I'd appreciate it.


I don't completely understand, but might be able to point you in the right direction. For starters, get these two free programs, they are excellent resources for Garmin devices and software. One is for working with the files on your computer, the other is for managing the GPS itself. They will let you change map names to whatever you like.

And he has this one for changing names too

But you may be running into another problem if you have a bunch of maps. Your GPS has a "segment limit" which applies to the smaller tiles inside each map. IIRC, devices of that age had a limit between 3000 to 4000 segments. There is no standard size segment, it's up to the mapmaker, so it could be a whole state or just one town.

Anyway, in most cases you will reach the segment limit LONG before you fill an 8gb memory card. For example, I don't think you could load even two of Garmin's own 24k topo products on your Dakota without passing the limit. And I don't think it's possible to load the entire US OpenStreetMap due to segments also. Garmin's old 100k topo map had the same problem, you could only load about 2/3 of the US due to segments.

It doesn't matter whether the map is on a card or internal memory, enabled or not. The segment limit applies to all maps you have installed. If you pass the limit, some maps will be missing or incomplete. No way to generalize because it depends on your exact combination of maps.


Thanks Boyd,

I'll take a look at those programs. Currently I've got about half of the US installed either on the state level topos or the bigger combo maps. But the segment limit you mention is probably also and issue, which might explain why some of my "renamed" files aren't showing up.


So, you are saying you've installed about 25 topo maps from GPSFileDepot? If so, then I suspect that is too many. WAY too many. I know there are some other obscure limits that have been discussed about how many map files are allowed.

This says your Dakota can handle 4000 segments:

You can use Javawa device manager to see how many segments are installed on your GPS: