Garmin map products, PC to Mac

[+user13371]

Garmin mapping products are different between their PC & Mac versions. Data is data -- moving from one system to another shouldn't be complicated. But Garmin requires two conversion programs (one at each end) to move maps from PC to Mac - and a dozen file formats internally* ... Any idea why?

 

* Really -- A dozen if you count this way...

• On the PC: IMG files for each tile, and one MDX and TDB file for the collection.
  
• Enroute: GMAPI, optionally compressed to TGZ
  
• On the Mac: GMAP package file for the whole collection, containing new versions of the MDX and TDB files; an XML file to describe the map collection; each tile is a subfolder containing a LBL, RGN, and TRE file.
  

Edited September 28, 2008 by lee_rimar

[Michael Cook]

I also wonder why moving maps from PC to Mac should be so complicated. In all of the map files I've looked at on PC and MAC, the TDB and MDX files seem to be identical: I don't think the ones on the Mac are new versions. The LBL, RGN and TRE files (and maybe others such as NOD and NET) that are visible inside the GMAP package are also to be found embedded in the IMG files. At Sourceforge you can find some info about the Garmin IMG file format.

 

I'm guessing that a competent hacker could quite easily devise a program that does what the Garmin converter programs do.

[+macnetz]

Garmin mapping products are different between their PC & Mac versions. Data is data -- moving from one system to another shouldn't be complicated. But Garmin requires two conversion programs (one at each end) to move maps from PC to Mac - and a dozen file formats internally* ... Any idea why?

Hi,

 

there is only one conversion in this process. From the disk image format to the Mac OSX package format.

The files included are the same. And the MapManager just copy the package to /Users/user/Library/Application Support/Garmin/Maps

 

Regards - Anton

Edited September 28, 2008 by macnetz

[+user13371]

there is only one conversion in this process. From the disk image format to the Mac OSX package format.

Guess it depends how you count.

 

A program on the PC takes a bunch of files and packages them into a single GMAPI file.

 

You copy the GMAPI file to the Mac.

 

A program on the Mac takes the GMAPI file and copies it to the GMAP package file, which contains the same bunch of files as were on he PC, but arranged differently. Each IMG file from the PC become three separate files on the Mac: LBL, RGN, TRE.

 

I'd call that two conversion -- and even though the data is the same, the arrangement on disk is significantly different across systems. Why not simply use the same file format and folder hierarchies on both systems?