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[mkgmap-dev] Index branch - success!

From WanMil wmgcnfg at web.de on Mon Feb 14 18:16:15 GMT 2011

> On 12/02/11 15:32, WanMil wrote:
>> I observed that the MapSource search menu is disabled if the MDR file is
>> larger than 0x7FFFFFF (134217727) bytes.
>> Maybe in this case a flag must be set?
> My guess is in ImgHeader:
> // This sectors, head, cylinders stuff appears to be used by mapsource
> // and they have to be larger than the actual size of the map.  It
> // doesn't appear to have any effect on a garmin device or other software.
> int sectors = 0x20;   // 0x20 appears to be a max
> header.putShort(OFF_SECTORS, (short) sectors);
> int heads = 0x20;     // 0x20 appears to be max
> header.putShort(OFF_HEADS, (short) heads);
> int cylinders = 0x100;   // gives 128M will try more later
> Try boosting cylinders to 0x200, or try to find if there is a maximum
> useful value like it appears that there is for the others.
> ..Steve

My first simple tries were not successful. MapSource reject the maps 
with changed cylinder values.
So I have started to implement the display for the IMG file header to be 
able to analyze it. There are many solutions possible:
* Wrong E2 value? My large MDR-IMG files use E2=3. This seems to be too low.
* There are still quite a number of unknown bytes. Some of them are set 
in my official Garmin maps.


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