are the help files in Garmin deleteable in order to gain space?

You can also delete all the unwanted EULA, text and keyboard files.

To gain additional free space in internal storage, can you put a larger portion of the map on SD (up to 2 GB) and a smaller portion in internal memory?

You can remove all but the English language files as well as any extra icons you have for different car symbols which show on the map, just leave one.

33MB of space seems so trivial today but back in the early 1980s after I moved from an Apple IIe to a PC, an AT&T 6300 with an 8086 processor and two floppy disc drives, I decided to replace one of the floppy disc drives with a hard drive.

Both 10MB & 20MB hard drives were common at that time but I decided to splurge and for the paltry sum of $420 I bought a 30MB hard drive. I thought I was the cat's meow with tons of space to store most everything. How time and technology have changed from those days.

http://www.poi-factory.com/node/41876

I seem to have as many files removed as I can....

Alan, I was reluctant to remove the old map on internal drive.. I didn't know if 660 would boot if no maps were installed on internal drive.
Could I just copy it from internal to a backup folder on SD, delete the maps off internal and the 660 would still be happy that way?
As I cycle between SD cards, I could copy 2012 maps to all SD cards and therefore have a backup in multiple locations... Is this do-able?
I believe the last map that fit internally was 2012...
By renaming current 2019 map on SD it see's both, and via maps I can select which I want to use...

If that's a viable solution, that would fix everything!!!

As long as you haven't deleted the gmapbmap.img file which is the basemap for your GPS you shouldn't have any problem booting the device.

Also I think your fairly limited to what you name your City Navigator map files. If I remember correctly you can only use gmapprom.img and gmapsupp.img, although you maybe able to use multiple gmapsupp files (e.g. gampsupp1, gmapsupp2 etc.). As alandb mentioned, there is also a 2GB file size limit for these files.

I think you're correct in worrying that the sup1 and sup2 options won't exist for a 660. Our DorkusNimrod wrote in:

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

and since the 660 is almost a couple years older than the 7x5 series, I think the prom (device) and supp (device or SD) filenames may be the only filename options that will work for a 660.

The limited filenames and 2GB filesize limit make the 6x0 series one of the toughest to update maps with all of North America and it prevents the normal clone technique to be used to install all of NA to a SD card.

Thanks for that info.
To be on safe side. I’ll leave it ‘as is’.
Now that I know there is no delete able files left,
If I need more space I’ll load fewer POI’s
Map upgrades are easy on 660.
I followed info from Alan and copied Garmin
Root directory onto SD card, and when GE ‘sees’
That SD card, it thinks it’s the 660, which is accessed far faster than the USBV1 port on the 660..
After map file update I rename the three files, and I’m off to the races!

Does anybody know when “Too Little” space will affect operations???

Is the alandb info his FAQ on the clone method? What are the three files you rename? How do you avoid a file exceeding 2GB? Does this give you all of North America?

I ask this as alandb's cloning FAQ states:

Important note for nuvi 3xx, 6xx and 5000: Cloning is not recommended for these models.

I don't own a nuvi 6x0 device so I have no firsthand experience on doing full North America map updates on one.

@JanJ ... Here is what I would do on the next map update...

1) Use cloning (with MapUpdater) to install the largest region that is below 2 GB to the SD card. I believe "Lower 49" selection is still below 2 GB so that may be a good choice. Rename these new map files from gmapprom.* to gmapsup.* as stated in the cloning discussion. Select the option to install to both device and computer, as that will get the full NA map on the computer for you to use with MapInstall.

2) Now use MapInstall to put the remaining map regions in internal storage. If you used Lower 49 for the SD card, then select Alaska, Canada and Mexio with MapInstall to install in internal storage. Note that you may need to manually delete the old gmapprom.* files in internal storage to make room for the new files from MapInstall. Back up the old files first to be on the safe side.

3) Boot up you device with the SD card installed and test to make sure the map is being displayed correctly in all regions.

This should give you ample free space in internal storage.

Since the nuvi 660 does not have any "feature" files (like junction view or speech recognition), you don't need to worry about installing anything except the map files.

Disclaimer: I have not tried this exact combination of methods to install a map to a device. AFAIK, it should work without any problems, but you will need to assess the risk and decide for yourself if it is worth trying.

Good info from all previous posts, Thanks

That is a valid point Craig, and that recommendation is based on the 2 GB file limit and Garmin Express' behavior of not offering to install smaller regions when there is sufficient space on the target device (the SD card in the case of cloning). That makes cloning with Garmin Express difficult (if not impossible) on these old devices with the 2 GB file size limit. So if you want to clone for these old devices, the old MapUpdater program is a better choice because it does offer the option for reduced region install.

I changed my earlier post to JanJ to indicate that MapUpdater should be used for cloning. Thanks for pointing out my omission of that needed piece of information.

With /Garmin directory on SD Card, it acts as a GPS to GE, and is far faster in download...
The 3 map files gets renamed to:
gmapsupp.gma
gmapsupp.img
gmapsupp.unl

on SD card.... and it works fine.... in a 660.

Gonna leave things as they are.... with regard to freeing up more space....

I have a better gps, but this is one I take on trips, because if it gets lifted, they'll have to guess login within three attempts or it locks itself out...

Can I assume you don't update all of North America but instead choose a region of the USA that's less than 2GB in size and appropriate for the areas you travel?

It has done lower 48 states since I've been downloading to SD card...
I believe GE used to not recognize the 2GB limit (3+ years ago???)
but now it does, and prompts for lower 48 states auto-magically!

Ah, OK. As long as you don't need Canada, Alaska, Mexico, etc. you are doing updates the easiest way.

@JanJ ... if you have the maps on SD card, what is taking up all the space in internal storage?

This 660 defies dying....
I've been on SD card for maps since 2012 Map version which is still on GPS...

The rear charging/Traffic/Power interface died 4 or so years ago... At that time I installed a new, better battery.... With that in, It, too died, and I tried a different power adapter which didn't work--that's how I determined for certain that the rear interface had died... not anything else...
I made a custom 5 to 4 pin USB cable to power it off Side USB connector, to allow it to run GPS and not go to computer transfer mode... It came back to life and still works!

It could be that this new power connection, though it works, is why the screen is not a bright as it used to be... but it still works...

The directory structure has been scrambled for longer than 5 years.... so I can't back it up... But it works....

It's battery life is fantastic... I'm continuing to use it basically because it has failed and been recovered multiple times.... and I just want to see what will happen next!!

I don’t know. Could be the scrambled directories.
I still have all the 2012 Mapfiles on it

I would run Microsoft's disk check utility on it. Yes, I know there is some risk, but I have used it many times on my Garmin devices without a problem. Disk Check itself will probably free up a few MB of storage. My old 755 and 855 seemed to get corrupted every now and then, so I always used the disk check to fix them. If that works, I would back up the old 2012 map and delete it.

I think the dimming of the screen when plugged in directly to USB is standard behavior for all nuvi's that have a powered mount.

I don't know how close the Lower 49 region is to the 2 GB limit, but at some point it may exceed 2 GB and you will need to split the map between internal storage and SD card.

Copy all the files to be deleted to the computer. If anything important missing, you can copy it back.

@zgpan ... I think JanJ has told us in the past that he gets a read error when trying to copy files from his 660.

Yes. It’s one of the things that make this 660 unique

And I’m amazed on how it keeps on working through all
These “Issues!”

Alan I’d say the screen lost 20% of brightness switching to side USB for power. Ok except for brightest days, but since audio level was boosted 2 steps with text to speech editor, that alerts us to route changes during brightest days. I believe I ran chkdsk on it once inadvertently,
But it reported an un-recoverable error. I’ve since
Not ran it.

Unrecoverable error is not good.

But the 660 doesn’t apparently know that, and so it works anyway!

I always deleted the old map image before loading new map if I needed room. But now I use an SD card for the file.

This is helpful advice.

good to know. thanks