Large JCV File Download Link

Thank You..

Thanks for the links

Thank you for the large jcv file link.

...it was a joy to wake up and see that you had once again made the large JCV files available to those of us with old devices and a desire to get all the Views we can.

It always takes me a long time to back everything up with the new stuff in the right places, and then run a simulation. I think Garmin provided a few additional Views for the route in the Denver area this time.

I just finished up with good results.

Thanks again, and "keep on truckn'".

Thanks again! Your efforts are appreciated.
Mark

It is interesting that those files are not delivered to my RV780Mt, with a microSD card (that is not used at all by Garmin).

Thank you very much

See:

http://www.poi-factory.com/node/45292

Downloaded.

Are both files needed now on a Garmin 1450? It used to be just a single file like D3060380A.jcv

That is a good question and one that I would like to hear an authoritative answer to. From my testing on my nuvi 755t and nuvi 855, I think it is only using one of the files, namely the larger one of the two. The key word here is "think", meaning that I don't know the answer. It is just based on my observation.

The file structure of the .jcv files has always been a mystery. A Google search for "garmin jcv file format" this time produced a couple of interesting results. "Garmin JCV file structure" (https://www.pinns.co.uk/osm/JCV.html) actually defines the header structure of jcv files. Still a lot of unknowns, but a start. "Multiple JCV files for CNNA 2022.10 " (https://www.navitotal.com/new-maps/multiple-jcv-files-for-cn...) discusses the different jcv files for CNNA2022.20. Conclusion is that the largest file is North America and the others are regional jcv files. The most interesting portion of the above post is an image of the application ImgTool displaying the contents of a jcv file! Google search for "Garmin ImgTool" produced the result "ImgTool" https://sites.google.com/site/sherco40/imgtool Unfortunately, I downloaded the file and McAfee detected it as a VIRUS. Further investigation seems to indicate that this is a false positive. I have sent the file to McAfee for verification. I'll post the results when I hear from McAfee. If this program is safe, it will answer many questions that we have concerning the contents of jcv files.
Mark

That is my theory also. But why Garmin downloads both files rather than just the one appropriate for the map version you are using is a mystery. Anyway, thanks for your research and let us know what you find out.

On my nuvi 755T (which downloads both versions of the .JCV file), I have left both of them intact on the SD card. But on my nuvi 855 which requires me to copy over the large JCV file from my 755 install to replace the puny one Garmin provides on the 855 thru Express, I only copy the larger of the two files. I have simulation tested several long routes on both devices checking every displayed junction view, and get the exact same views on the 855 with one JCV file that I do in the 755T. That observation from an admittedly small sample of routes is what I based my conclusion on.