.img files?

I'm confused re.

gmapbmap.img
gmapprom.img
gmapsupp.img

gmapprom is the default mapset (ie, for your home country)?

gmapbmap is "base map"? Surely this isn't a complete detailed map: the file
size is only 15 percent of the other .img files. Why so small? What is a
"base map" and how does it differ from a mapset?

gmapsupp is secondary mapset? If, for example, you want to visit another
country you can load a map onto an SD card and name it gmapsupp.img?

Which of these are required; which are optional?

Is my understanding correct?

Tx.

 

here's a re-post of mine - from Jan 2010

BTW - You might indicate what GPS you have,
and what maps are listed in your "About" screen.

---
After a recent map update to my Garmin Nuvi 255 GPS,
I looked at the GPS sub-dir to see how big the map image file was...

In looking around the GPS sub-dir,
I noticed a couple of other different files....
These appear to be the new TimeZone files -


SO - this is my D:\Garmin sub-dir of map info


gmaptz.img Time Zone map info
gmaptz.sum


gmapbmap.img 92mb - basemap
gmapbmap.sum


gmapprom.img 1.1gb - latest CNNT 2010.30
gmapprom.unl guessing map unlock code
gmapprom.sum


gmapsupp.img 19mb - my topo map segments

 

Garmin Nuvi 660

 

So, which are required and why?

And why is a "basemap" only 92mb and the primary mapset is 10x that? What's
in each? Are both needed?

Thanks.

==

 

Well - you can pretty much delete what you want,
and then you'll have no maps - and a pretty useless GPS

Why are you asking about deleting things ?
Are you looking to delete to save space or what ?

You replied that you have a Garmin 660 -
BUT - What "maps" do you have installed ?
We have no idea what products you have purchased
or installed on your GPS - and each will create a file,
or a set of files...

Basemap - very basic map image with nothing else
Purchased maps - add more map details and POIs for reference/lookup.

 

What's the purpose of a basemap? You can't select a it. Is it only defaulted
to if no purchased mapset is installed? Does it become optional if a gmapprom
or gmapsupp file is installed? Can this be deleted if a purchased mapset is
installed?

I don't like files sitting around (on my computer or GPS) that aren't needed.
And this leaves more room for MP3's, audio books, POI's, etc.

Installed: NA mapset including USA & Canada

Planning on getting Europe too.

 

It is a world map with only continental coast lines and major metropolitan
areas marked as single points. There are variations on some models where
the basemap also includes more cities and major roads of the continent you
purchased the GPS. For instance if you purchased the the GPS in the US or
Canada major roads of North America are included and other continents are
more limited and if you purchased a model for Europe there are some more
details for Europe but other continents like North America are very limited.

Technically you don't need the basemap and for regions where you have any
other map coverage it is more or less useless. If you look at an area where
you do not have map coverage it will provide some information about where
you are while when you delete it you won't even see whether you are on the
ocean or on within a country.

Considering this example that you have:

If you travel to Europe without buying additional maps you would still see
cities like Paris or London from the basemap. If you deleted the basemap
you wouldn't even see that there is a continent at all.

Robert

 

[...]
Robert

Thank you Robert. That fine, thorough explanation is exactly what I was
looking for.

You'd make a good writer.

Another Q: is there an editor for separating mapsets? If a purchased mapset
which includes USA & Mexico, and I already have a map of USA, how do I edit
the USA / Mexico set so as to delete USA (I don't need 2)?

(FYI, I'm using OS X.)

Thanks again.

 

Hi Robert,

Be careful - the GPS uses this mapset at a resolution of (depending on
details settings) 12km to draw the display, and no longer the
purchased mapset. I believe this is for speed resaons.

So, there is a need for the file to be there.
--

Ciao,
Holger (GUS-KOTAL, GUS#1100, GRR#51)

90-92 Honda CB400 10 Mm | 93-95 Yamaha TDM 850 26 Mm
95-97 KTM 620 LC4 13 Mm | seit 97 BMW R1100GS 69 Mm (Die Renndrecksau!)

cu @ http://www.issle.de

 

Be careful - the GPS uses this mapset at a resolution of (depending on

Thank you Holger.

"The plot thickens" .

So no matter how many brand new map sets I have installed, the Garmin needs
the gmapbmap file?

 

Rename the file. If you discover that you need it, rename it back to
original.

 

In my experience it makes use of it. Map drawing is much quicker if
the basemap is present at a specific scale of display, and there will
be no more map display if the basemap is missing, at an even bigger
scale. Exact numbers depend on your model and detail settings, so try
it. The basemap assists as well in some searches.
--

Ciao,
Holger (GUS-KOTAL, GUS#1100, GRR#51)

90-92 Honda CB400 10 Mm | 93-95 Yamaha TDM 850 26 Mm
95-97 KTM 620 LC4 13 Mm | seit 97 BMW R1100GS 69 Mm (Die Renndrecksau!)

cu @ http://www.issle.de

 

If it is lack of space that is the worry why not install an additional
card. I installed a 8GB card in my 660, it gives ample room for all
the MP3 etc I'm ever likely to need.

Pete.