Adding Map

Create a Garmin folder on your SD card and copy the map file into the folder. Rename the map file to gmapsupp.img, see if this works.
Sendmap20 is used to add the map to your Mapsource program on your PC.

Mostly likely just copying the IMG file to the unit (or the card) and renaming it will not work.

Using sendmap20 is the correct procedure and should produce the GMAPSUPP.IMG file. The GMAPPROM.IMG file containing the preloaded maps on the unit will not be affected. But if you are at all worried, by all means install the map to to the SD card. That will work.

Also, it's always advisable to create a full backup to the unit to a computer before you do any major operation. Then if something goes wrong, you can copy the files back to the unit.

Prior to posting a question, I did try to use sendmap20 without my GPS device connected to my notebook. I did see a new file (GMAPSUPP.IMG) created on my PC desktop but the size is 0 byte. Not to worry about it because I didn't complete the whole process. That's why GMAPSUPP.IMG size is 0. I guess I'm on the right track.

Ok, so here's what I understand so far (correct me if I'm wrong):

- Nuvi preloaded map is called GMAPPROM.IMG

- Use sendmap20 to add the downloaded map and to produce a GMAPSUPP.IMG file (a Garmin compatible map file?)

- Then copy/paste the new IMG file to my Nuvi 760

I'll try that tonight. I'll be back to post the result or to ask more questions, if there's any. Btw, I do have a backup but I'm still worried that I can't tell what files on the device get overwritten when I use sendmap20.

Thanks again.

That's correct. Let us know how it goes.

i have downloaded .img files and just copied to the GPSr's /garmin folder, renaming it to gmapsupp.img and it worked fine.
i used sendmap20 to install the same map file to Mapsource.

Did you download the IMG file from the same site that I mentioned?

So we can have both GMAPPROM.IMG and GMAPSUPP.IMG files simultaneously on the GPS device. How does it know which map to use?

I'll try to do it that way (copy/paste without using sendmap20). If that doesn't work, I'll use sendmap20.

Yes. See my mapset naming topic for mapsets/mapset names that you can have on the unit at any one time:

http://www.poi-factory.com/node/19164

It's hardcoded in the device's firmware

Thanks. I looked at the link. First thing that caught my eyes is this: +Updated items 12/18/2009

Are you from the future?

I don't get it. Perhaps I should put it another way. If I put a supplemental map, let's say Europe map, how do use it?

Btw, maps at http://gpsmapsearch.com/ are so small in size. The size is only a few KB or less than 100MB. Are they for real? Has anyone used their map?

Thanks for the heads-up on the incorrect date. It has been corrected.

You don't need to "do" anything to use the supplemental map, except for maybe enabling it from Tools>Settings>Map>Map Info and disabling City Navigator maps from the same menu option.

The maps reside on what are referred to as "display priority layers" with City Nav maps having the highest display priority (no others will display on top of them unless they are designated/flagged as being transparent). Thus if you have both City Nav maps and Topo maps on the unit at the same time with both covering the same area, you will need to deselect the City Nav maps and select the Topo maps to see the Topo maps. If the maps are NOT covering the same area, you can leave both enabled since the City Nav maps won't be displayed on top of the Topo maps.

If you have both maps on the unit and both are selected and are covering the same area, you'll only see the City Nav maps.

I like the maps available on that website... my problem is that I already have the 2010 maps loaded using the available username and could not find a way to load these maps into the MapSource as well.

as suggested by mariner
- Rename IMG file that I download to GMAPSUPP.IMG
- Copy/paste the file to \Garmin\ folder on my Nuvi

as suggested by MM
- use sendmap20, add a map file and create GMAPSUPP.IMG
- Copy/paste the file to \Garmin\ folder on my Nuvi

Neither one of the above produce any difference on my device. When I click View Map, I'm seeing the usual North America City Navigator. I added a new map for an Asian country. I can see the additional map in Tools > Settings > Map > Map Info
That's pretty much it.

Could it be a non working IMG file? The size is only less than 10MB. I thought a map file has to be at least in the hundred of MB neighborhood. For example North America City Navigator file is about 1GB.

Did you see my post above? Particularly about map priority?

Yes I did read it and I thought I understood your post.
Unchecking City Nav does not make any difference. I still can't see the supplemental map.

You think it's a bad map?

If the map is listed on the Map Info screen, then it should be showing up on the unit.

Did you deselect the City Navigator map and then scroll the map to the area of the new map?

I think the light bulb just lights up. I did deselect City Nav and went back to press Show Map. At that point the map shows a car at my home (my current location). However, I did not scroll to the area of the new map. I've never scrolled the map beyond my city or state Whoaaa.. I'm an idiot.

I don't have my GPS with me now. Gotta wait until after work. Thanks again.

You have to select Wrench->Map Info (at the bottom) and you'll see the maps that are installed on the unit. Select the map that you want. You can test this out by searching for a POI by Where To->Search Near->Different City->enter a city that's on the map and search for a lodging or food poi and select Show Map. If the map is working, it should show you the location of the poi on the installed map.

Great tip. I'll be back tonight to post my findings.

I am so happy to find this at right time... Thanks everyone!!!

BEst
R

rahool, feel free to add comments to this thread. Perhaps there are things that I can learn from you too.

The above won't work on most (all?) third party maps because they don't contain searchable POIs.

I zoom all the way out and scroll to the area of the supplemental map. It's there. I don't think it's searchable though.

I press Set Loc and a car pops up on the map at the cursor. Try to search Near a city. It doesn't even know a city name on the map.

I appreciate all the help I got. Thanks all.