Hi Gerd Have been checking a few garmin tdbs and it appears that while the first 3 bytes remain the same for each, ie 01 00 00, the last four bytes are always different and never zero ! also ,except with mkgmap tiles, I have not come across C3 in the second byte ie a 01 *c3 *00 Nick On 05/02/2018 08:36, Gerd Petermann wrote:
Hi,
Ive discussed with Frank if there might be a field in the tdb file that has to be changed. Maybe there is a value that tells MapSource something about the alignment of DEM data?
I don't have a single original Garmin tdb file :-(
It seems that mkgmap writes some constants that might be important, e.g. MapDetailBlock.java contains //01 c3 00 ff os.write4(0xff00c301); os.write(0); os.write(0); os.write(0);
The wiki [1] describes these 7 bytes as "byte:0 has copyright text,byte 1: has 0x53 text : byte 2:if 1 then bytes 3_7: an unknown total (density)"
The display tool seems to expect something similar to the wiki: d.rawValue(2, "01 01"); d.byteValue("intro flag"); d.intValue("intro %d");
Any idea what this "intro" or "unknown total(density) could be ? And what is the 0x53 text?
[1]https://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/TDB_File_Format
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