Thread: How to install multiple maps on Garmin the easy way

You cant have enabled routable maps that cover the same area and that overlap, this can be your problem-
The basemap must be apart and cant be deselected and must be named gmapbmap.img if you want it can work properly.

Sorry to ask a repeated (maybe) question, but I have spent 3 days and 1 night on your excellent site and I need to go to bed (it is almost 10am local time)

I have a NUVI 370, a NUVI 755T and a NUVI 1450 in hands and I have some questions on multi-map installation:

0) In all the questions below, I talk about ROUTABLE and SEARCHABLE maps (otherwise I regard the maps useless - for me at least) - Please take this into account!!

1) In the tutorial on the first page you do not mention if it is the internal memory or the SD memory and you mention a GARMIN folder - for example the 370 has all these files (gmapbmap.img, gmapprom.img and gmapprom1) in the root of the internal memory (no Garmin folder in the int-memory as you mention in the tutorial) - Do I miss something?

2) How many MAXIMUM .img files can I have in the int-memory and how many maximum maps on the [SD]\Garmin or elsewhere? - In the 370 the gmapsup1.img or gmapsup2.img on the SD-card cannot be "seen" - Do I make something wrong (I am maybe tired by browsing your site)?

3) I noticed that gmapsup1.img is not permitted but gmapsup2.img is OK - Correct? Why? Isn't it strange?

4) The *.unl file (single file) or many *.unl files: where do we put them? Together with the associated file(s) (same folder) or in the [Garmin unit] root folder or [Garmin unit]\Garmin?

5) Can I try to load maps into the [Unit]\GARMIN\App\ folder or/and [SD-card]\Garmin\App in the above NUVI's as you claim on the 1st post - or "try on error"??

6) To increase the number of maps, I can load one .img file with combined maps and then select from the program menu, say only 1 map of the set, but this map will NOT be SEARCHABLE (i.e. useless, for me) - Please confirm.

7) If I put overlapped maps, (example: gmapprom.img = CT Europe NT 2011.04 (including GReek street names w/latin characters) and gmapsupp.img [in the internal memory OR in the SD card] (a very detailed map of Greece w/street names in Latin OR Greek-I have both maps), will there be any problem/conflict? If not, which map has precedence? i.e. having EU(Latin) and GReece(Latin) loaded (and selected!!!) when I search a street in GR typing Latin letters, which map will be used or make the automatic search?

8) I hope there is no problem of having {maps unlocked} together with {maps locked and their respective *.unl files}. Confirm please.

9) If I mess up the maps (*.img) files is there any possibility to make the unit UNUSABLE?
Strange question you might say but I screwed up a 755T a month ago-I deleted the gmapprom.img file FIRST and then copied a map with the name gmaprom.img instead of gmapprom.img (I missed one "p"). The result was that it did not boot AT ALL and no connection possible w/the PC. From what I have read/studied in your site it should not be the case of damaging the unit but I am PRETTY SURE that this is what I did between "working" and "not working" status of it. Do not claim removing the unit from USB port w/o first ejecting it (I am an electronic engineer and a very experienced user of PCs - it was not the case with me!!! - Perhaps it was to happen to the unit and it was not the change of the file but please answer the question based on your big experience) Unfortunately, I had to (fortunately) replace it (it was still under guarantee-bought <1 month before) and get a new one.

10) Finally, noticed that filenames have a max length 8.3 (filename=8 characters , ext=3 - This reminds me of old DOS files). Is it correct?

Then what was written in post #57 might be wrong !!!!:

Post #57
Some times has left and as nobody was interested to give exact instructions, I took a time and made it clear for my self.
At Mobile XT I go working in folder garmin following file (map) names:
gmapbmap.img;
gmapprom.img;
gmapprom1.img; <-= LOOK HERE PLEASE: FILE LENGTH IS 9.3 not 8.3
gmapsup2.img;
gmapsupp.img.

11) Since the TMC receiver can be bought (I think) separately and plugged into(???) the USB socket, could the 370 and 1450 become 370T and 1450T? Is there a USB-socket TMC receiver at GARMIN gadgets (I can search the GARMIN site of course, but if you know, please tell me). The actual question is if the TMC s/w is embedded in the GPS s/w independently if the unit has a "T" in the model number - For example my 755T actually is a 755 model (refurbished) (printed on the label and on the about/help indication of the s/w) but I bought it as a 755T w/a TMC receiver cable/antenna and it works fine!! It was the replacement of the screwed up 755T (see Question 9), the original was a (refurbished) 755T with 755T label and 755T indication on the help/about info field of the s/w. I am saying that because another guy had ordered from the same store a 755T but received a 755 (probably with a TMC cable/receiver) but he was unhappy and returned it - I think this is a useful piece of info for your forum users to have in mind

The 755T TMC receiver uses another Garmin socket to send data to and to charge the 755T unit in the car. This socket is located on the GPS hold-system between the unit and the cradle. However, the unit has a USB-mini socket which can be used for connection to a PC or for charging.
The 370 has a traffic menu and when you select it it requests to connect the TMC receiver ;-) !!! but the 755T or 755 needs a TMC receiver connected to the unit (and maybe receiving TMC data) in order to show the TMC menu Probably the 1450 does the same (I have not tried it yet)

This is a lengthy and detailed post in order to make your answers as short as possible and hopefully help other users.

Thanks in advance!!! - George

Originally Posted by georgev

..................

2) How many MAXIMUM .img files can I have in the int-memory and how many maximum maps on the [SD]\Garmin or elsewhere? - In the 370 the gmapsup1.img or gmapsup2.img on the SD-card cannot be "seen" - Do I make something wrong (I am maybe tired by browsing your site)?

3) I noticed that gmapsup1.img is not permitted but gmapsup2.img is OK - Correct? Why? Isn't it strange?

.....

6) To increase the number of maps, I can load one .img file with combined maps and then select from the program menu, say only 1 map of the set, but this map will NOT be SEARCHABLE (i.e. useless, for me) - Please confirm.

7) If I put overlapped maps, (example: gmapprom.img = CT Europe NT 2011.04 (including GReek street names w/latin characters) and gmapsupp.img [in the internal memory OR in the SD card] (a very detailed map of Greece w/street names in Latin OR Greek-I have both maps), will there be any problem/conflict? If not, which map has precedence? i.e. having EU(Latin) and GReece(Latin) loaded (and selected!!!) when I search a street in GR typing Latin letters, which map will be used or make the automatic search?
...................

Thanks in advance!!! - George

Finally I did not go to bed - I will sleep tonight ... but I kept digging in this excellent site (4th day + 1 night) so I will answer to my questions for the benefit of other users having the same/similar problems:

Q2: It seems that 755T (which I have - the other units belong to friends) can use up to 9 *.img files (Lucky me!!) I assume that similar units supporting 3dmaps will have the same number. Other units ... better see the post of my co-patriot Santosan:

[Only registered and activated users can see links. ]
#6 of a greek fellow Santosan

ADDITIONAL INFO: I found out in the forum that Nuvis 1xxx can have MANY maps in the [GARMIN UNIT]\MAP\ folder OR in the [SD CARD]\Map folder and with different than the conventional names Requirement to have an .img extension (AnyName.img) and I SUSPECT file length 8.3 (filename=8 and extension=3), so PERHAPS you cannot have AnyName12.img (length9.3) - Please test!
However if you have/use the GARMIN folder of internal memory or SD-card then you must use ONLY conventional names (gmapprom.img, gmapsupp.img etc) even on the 1xxx units.
Can we have both? (MAP and GARMN folders) This is a good question!

Q3: gmapsup1.img is not permitted (see above same post) - I do not know why (yet!)

Q6: Combined maps cannot be searchable - I read it somewhere and I tested on the NUVI 370

Q7: We cannot have ENABLED overlapping maps (= maps covering the same area) [see post #53 above by catyman]

THANKS TO ... ME for the answers ;-)

PS: If a ... respectful expert could confirm the above, it would have more added value .... :-)