Copying maps from one device to the other

[deltaforce]

I have 2 Garmin devices. I have one device with the lifetime maps and another doesn't. I was wondering how can one copy maps from one device to the other?

Reading various threads on this board says that the maps are device locked. Is there any method to unlock those maps? Can anyone direct me to related write-up, if available?

Many thanks in advance.

(P.S. - Pls dn't suggest me to buy new maps or use OpenStreet maps. I would have bought new maps if the price was reasonable but the cost is $50+, which IMHO is totally unreasonable. Hence all the trouble.)

[Butters]

It quite depends on which device you have (the one without LM). As it is most likely an older device with only GMA protection in it's firmware then simply unlocking the IMG file with gimgunlock-0.04 will work. Google to find it.

[deltaforce]

Thank you.

I have managed to update the device (without the lifetime maps) with the unlocked maps floating around the web. So I guess, if I manage to unlock it, it should work.
Should I apply the same process for JCV file as well?

[Butters]

If the map you've downloaded has been properly unlocked and it's an older device then the file should work without anything further being done. Best to say which device model though.

JCV files aren't locked like map IMG files. We also need more info to properly advise you however. There are different JCV files, some are quite device specific others are broadly compatible ... e.g.: Some JCV files aren't interchangeable at all, however some split-screen and full-screen JCV files of the same 'type' are interchangeable but perhaps at the expense of picture quality. In short, it's 'horses for courses' and best to disclose completely the device you're updating and which JCV file you want to use (if you already have it).

[deltaforce]

Thanks again.

The device in question is 1390T. Its on its last legs so I am trying to see how things work with Garmin devices. It has lane assist, junction view features but other than the original maps it came with, I have never seen the junction view. Lane Assist feature works though. TBH, I don't even remember if its a full screen junction view or split screen like Drive Smart devices.

Plus, the original JCV file is pretty small, abt 45mb from 2011, name is something 1xxxxxxx.jcv but again I have never seen jcv files starting with 1xxxxx floating around the web. All other jcv files I see around the web are at least 500mb. So I am not too sure if I am using right files.

I tried searching if there is any nomeclature system for jcv files but none that I could find.

[Butters]

13x0 series uses full-screen files but can also use split-screen which will be stretched to fit and due to lower resolution/picture size will be a bit grainy/fuzzy. It can only use the SVG/JPG version of JCV however, not the Raster/BMP type. The former is used by (for example) US/EU nuvi 7x5, 1xxx, 2xxx and 3xxx devices most commonly, as full-screen for the first two and split-screen for the last two. If you're in NA then Garmin supplies a large JCV file for 7x5 which can be used in 1xxx devices however because of smaller internal flash size in 1xxx they usually supply a cut-down smaller version for them in, for example, North America. This may explain why you are seeing two different sized full-screen SVG files in your quest to track down the correct file.

Each version of map has it's matched JCV file. You can't use an older version of JCV with a newer map so your original JCV file from 2011 is useless with any later map version of the same type. Tell me what country and version map you're wanting to use on your 1390 and i'll see if i can find you a compatible JCV file for it (e.g. City Navigator US Lower 48 2019.30).

[deltaforce]

Thank you again for very helpful replies.

Its North America version. Thanks for offering to look up jcv file. At the same time, will really appreciate if you also explain how do you figure out which jcv goes with which unit? This is exact reason why I was looking for nomenclature, assuming there must be some defiined set of rules that garmin uses to dictate which device is compatible with certain (jcv)file or vice versa. I could not find such nomenclature, not even cursory ideas.

Currently, I have D3060280A.jcv (827mb) and D3191270A.jcv (485mb) but I have no idea which one goes along with 2019.30 lower states gmapsupp.img?

Any idea if things have changed with Drive**** unit variants, as in maps or jcv files?

[Butters]

D3060280A.jcv is native to nuvi 7x5 devices using full screen views, it has a length of 868,205,210 bytes (~827MiB) and 123,525 views with picture size of 480*270 and is fully compatible with your 1390.

D3191270A.jcv is native for later released devices such as nuvi 2xxx/3xxx> using split screen views, it has length of 509,166,591 bytes (~485MiB) and 125,992 views with picture size of 212*234 but will display in your 1390 as I said in previous post. The fact it has slightly more views than the big full screen file yet is only a bit over half it's file size is explained by the smaller picture sizes of the images, 212*234 vs 480*270.

D3153280A.jvc is (I think) the 'cut-down' full screen version Garmin offers via GarminExpress for 1xxx series in NA. Length is 26,499,137 bytes (~25MiB). It's got only 19,682 views. If you want it let me know 'cos I've got a copy. It's pretty-much useless though with only around 15-16% of the views of the other two files.

I don't really understand your question about Drive variants maps and JCV files, what exactly do you mean by 'changed'?

[deltaforce]

Thanks again.

If you don't mind, I would like to try the third file.

My question, to put it plainly, how do you figure out which jcv file is compatible with which devices? Does this info come from Garmin directly or is this info embedded in some file within this jcv file?

[Butters]

Garmin doesn't make it easy to find out what JCV goes with what IMG, however once you know the sequence you can work it out. For instance, NA 2019.30 uses D3060280A.jcv so next version will use D3060290A.jcv. So the progression is by 10 in the file name for each map release. You can open the JCV file in [Only registered and activated users can see links. ] to see when it was made which will indicate it's relationship to a given map version without looking any deeper.

[Only registered and activated users can see links. ]

Here's the link to download D3153280A.jcv:

Spoiler:

[Only registered and activated users can see links. ]