Easily ID Overlapping Maps?

[Adk Keith]

Hi folks,

What a great site, thanks. I searched for this topic in the forums and didn't find it, so here goes.

Is there an easy way to id overlapping map tiles. I have Garmin's 24k Eastern Parks as well as the NY topo coverage from this site. I would like to use Garmin's coverage for the parks and turn off the NY topo tiles that overlap.

Is there an easier way than individually locating the individual tile images in Map Source then going to the gps and turing them off? Is there info in the tbd file that can be cross referenced or something?

TIA

Keith

[maps4gps]

Is there an easy way to id overlapping map tiles. I have Garmin's 24k Eastern Parks as well as the NY topo coverage from this site. I would like to use Garmin's coverage for the parks and turn off the NY topo tiles that overlap.
Is there an easier way than individually locating the individual tile images in Map Source then going to the gps and turing them off? Is there info in the tbd file that can be cross referenced or something?

It would be very unlikely that the boundaries in a tile in GParks would correspond to one in NYTopo. 
In NYTopo the .img file names use the 2-4 position for long, 5-6 for lat, and 7-8 for an interleave of tile size and location within the 1 degree square.
On some Garmin models you can hide/unhide all the tiles of a mapset - from the map page, menu, setup map, information (has a list of the tiles in each mapset), menu (show/hide for the mapsets which are loaded on the GPSr) - this last option is not available on some models.
The .tdb may contain this info, however the file is binary.
On my version of MapSource, if you click on a tile a second time it removes it from the list in the left hand window.  The map name corresponds to the .img file name.  You could use that method to find which NYTopo tile/file is where and build a list for yourself if you only wanted to turn off a tile or two rather than the entire mapset.