City Select V6

[+skyspeak]

Is there any way to reduce the amount of data that city select transfers to the GPSr? Specifically, for a given area, can I turn off POI's or other data? I have a Map 60 with only 24mb?

[+Lil Devil]

On the Maps tab, at the bottom, is a checkbox to "Include route calculation data." This will minimize the download somewhat, but you'll lose the info needed to do turn-by-turn directions. Other than that, just choose fewer map sections.

[+Sagefox]

I think your Map60 should have 56megs of memory. I can load enough maps and data to drive between just north of SF Bay area and Seattle and cover the coast, I-5 and Highway 97 routes with no problem.

 

Even if you have only 24 megs of memory that is enough cover one area very nicely.

[Keystone]

I am moving this topic to the GPS Units and Software Forum.

[+Team DEMP]

If you have the GPSMap 60 then you have a unit with 24MB of memory for maps.

 

I had a GPS V with 19MB of memory before I got my GPSMap 76CS. With 19MB of memory, you need to select specific areas. The smallest item you can download is a specific map segment, so select only the ones you need.

 

Yes, you can tell it not to download routing data which will make the segments smaller, but then you lose a big feature. Even without routing data, the POIs are downloaded and from what has been previously reported, the POI data is minimal.

[Neo_Geo]

I have a theory. Bear in mind that I have never actually done this, so I cannot confirm this as truly doable, but it may very well be worth looking into. It is definitely possible to make your own Garmin compatible maps (I'll provide links at the end of this message). It is also my understanding that you can take existing Garmin .img files and reverse-engineer them in the same way that you make your own. The problem here is that the file ends up being TWICE as large as the original file. But then that's okay because most of the original data is POI data anyway!

 

With that being said, in the make-your-own maps process, the desired POI data is contained in a separate file, but it is not necessary to have POI data in your maps. So, if you were to break-down an existing Garmin .img file, extract and remove the POI data, and then rebuild the actual map image file, you could then end up with smaller .img files with no POI data.

 

Example:

Original Garmin .img file is 1MB in size

Let's say 80% of it - or 800,000 bytes is POI data

That means that 200,000 bytes would be actual map data

Rebuilding the image file makes the file 400,000 bytes

The file is reduced to about 40% of it's original size.

 

Bear in mind that - AGAIN - THIS IS ALL THEORY - so your mileage WILL vary!

 

Hope it helps...

 

cGPSmapper

Map Authoring

Custom Garmin Map Tutorial

UMP: GETTING STARTED

Ozi Explorer

GPS TrackMaker

MapDekode

cGPSmapper

Edited May 14, 2005 by Neo_Geo

[+Night Stalker]

I haven't found the POI's to be that much of a problem with my 60CS. Since it does have 56 meg of ram I have been able to load all of Idaho Montana and the LA basin clear out to Yuma Arizona and still had some memory left.

 

The other reason it hasn't been a problem is because the 60C and CS download using USB. Downloads that took as much as half an hour on my Magellan SporTrak Pro take only minutes now.

[Neo_Geo]

I haven't found the POI's to be that much of a problem with my 60CS.

The O.P. has a MAP60 - as in black & white with 24MB of memory