Copy of the same map with different typ files?

[LostAgain]

Hello All,

I'm wanting to use a map and a copy of that same map with each having a different .typ file on the 276CX so I can switch between them when desired.

I've tried putting both maps on the CX with different filenames but it only recognises one of them, the other one doesn't show up at all.
If only one at a time is on the CX they each show up correctly.

Is there some sort of ID issue that has to rectified in one of the maps so the CX sees one different to the other?
Can this be done?

The map is the free Australian ShonkyMaps

Thanks

[GPSrChive]

Garmin devices do not use the file name to identify maps, but rather hard coded ID data within the map itself.

You can load the same map multiple times using different file names, but the GPSr will see them all as the same map as their ID is 'hard coded' internally.

[LostAgain]

Can the ID be changed in one of them so the device sees them as different?

[0x01]

I don't now about this particular map. At least when compiling the map with mkgmap or gmt (GMapTool) you can specify the individual ID.
Since you can merge multiple gmapsupp.img into a single one, I suppose change of map ID will work by the same way (merge a single file).

http://www.gmaptool.eu/en/content/change-mapid

[LostAgain]

Thanks, tried changing map ID with GMapTool and it didn't work.
Also tried changing FID, PID and FID in MPS also didn't work.
I haven't tried splitting down to the individual tiles and recombining with a new ID yet.
Need more hours in a day

[GPSrChive]

Be advised, when you start changing all these values in a map file, some features can become permanently broken, and routing may no longer work as expected. All those numbers, including the TYP file number, as well as other internal MAP identifiers must all follow very strict guidelines for the map to be correctly displayed and functional on the device.

[LostAgain]

Ok thanks for the heads-up, it's not a routable map anyway so at least that shouldn't be an issue.
I'm working on a copy so doesn't matter if I break it while experimenting.

It's the guidelines I'm having issues with I believe, I haven't yet found a good explanation of what those guidelines actually are for each parameter, the ones I've found and tried so far haven't worked.

[GPSrChive]

It's the guidelines I'm having issues with I believe, I haven't yet found a good explanation of what those guidelines actually are for each parameter, the ones I've found and tried so far haven't worked.

Here is some 'lite' reading to help you down that rabbit hole....