Felix Hartmann wrote:

Steve Ratcliffe wrote:

On 21/09/09 17:03, Steve Hosgood wrote:

MDR 1:  A reverse index from maps to the other sections.
MDR 4:  poi types, partially known
MDR 5:  Cities
MDR 6:  unknown, wiki claims it is a list of cities but I don't believe that

I wrote that bit of the wiki, and for me at least it's true. This is
deduced from an NT map, with a record-length of 3 bytes. I wrote a


Yea, the big problem is that there is not just one format, I've no
idea about NT, but there are multiple different header sizes and
record sizes possible.  Also there is a big difference between the
full format as it comes with a map for mapsource, and the format when
it transformed and put inside the gmapsupp.

I didn't know that, but it's all in need of documentation eventually.
You're right though Steve - the wiki needs the sections talking about individual MDRs to specify more clearly what the record-size is, and maybe the other 4-byte value from the header too - the one tentatively marked "flags" or "?".

  
Why do you try to go for NT format?

Because that's all I've got.
At the time I started, I didn't realise there was anything unusual about the map I have (it's the one that came with my Streetpilot).

As for NT maps being slower - well it seems that they're using compression on the postcode, street-name and city lists. I can imagine that there's a speed penalty.

Steve.