Managing microSD cards and data maniplulation.

Started by ADKNeil, June 10, 2022, 07:37:41 AM

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First post.  I'm new to GPS file depot but have used Basecamp and Garmin products for years.
I have a couple of micro SD cards that I swap in and out of my GPS  (64st).  One has all of Quebec, the other the NE USA at 24k.  For all I know I could put both sets on a single card but that's how I have set it up and it works.  Being insecure about my skills, prefer not to change anything.

Now for my Q's.  I plan on driving and hiking around WY and CO Aug-Oct.  I want 2 map sets for each state.  One for hiking and another for my Drivesmart car gps.  I planned on using 4 cards one for each map set.  Make sense?

My next Q is in getting the maps from the internet into Basecamp and then into my SD cards and finally to read the maps on my devices.  I've (quickly I admit) read the tutorials but I want to make sure I have the correct sequence before I start.  So, here is how I think it will go....:

  • D-load file from GPS file depot.
    Double-click to install on my PC (it knows into which folder to install the maps I hope cuz I have no clue).
    Open Basecamp and open the map from the "maps" dropdown list.
    Plug in a micro SD card.  What's best, have the card in my device or plugged in directly to the PC's port?
    Click "send to device" and choose the entire state and let it transfer over.
    View in device to make sure it all worked.
Sorry if this is basic but my level of expertise is pretty low. 


I think you've got it down pretty well. I would use a built-in SD card reader unless your computer is really old with slow ports. In almost all cases, it will be faster and less prone to error if you create the card in the computer, then put it in the GPS.

I'd suggest installing these two free tools, they are really helpful for managing Garmin Devices. Unfortunately, the author had a serious health problem several years ago and is no longer updating these apps, so there could be compatibility issues with newer operating systems (especially on the Mac).

There's a less-obvious but important thing to check on your cards. Use the Device Manager program to check the total number of map segments on each card. See this info from Garmin's site, which says your GPS supports a total of 3000 segments.

Do not create a card with more than 3000 segments or it won't work properly. Some maps or parts of maps will be blank if you exceed the limit. Impossible to predict because it depends on the maps you are installing.

But the segment limit applies to ALL files on the GPS - the SD card PLUS internal memory. So you need to add those two numbers and make sure it is less than 3000. There's no standard size for a segment, it's up to the map maker.

Typically, you will hit this invisible segment limit long before you fill an 8gb SD card.


So, no sense buying sd cards with gtreater than 8 Gig of capacity.


Probably not, but do some quick research on your own and see how many map tiles you currently have on a card and how much storage is being used. There's an old thread here where somebody bought hundreds of dollars of the Garmin 24k topos back when they were selling them on DVD's. Then he was upset they wouldn't work when he copied them all to a big SD card.

But you could also download Birdseye imagery and put it on the card, that can get into a lot of gigabytes and is not part of the tile limit.


I just ran the program on a card and came up with this:

E-disk (E:\)
11.41 GiB free of 14.83 GiB
There is 1 map available in 1 file, total 3.42 GiB
Number of map segments: 1059

This is just a "naked" card, not inside my GPS device.
Looks like an 8 GiB card would have nearly 3K segments if all the same size (maybe not huh?)  Add what's on the GPS and a card of say, 16GiB plus the GPS probably would not work.

When I plug the GPS with a Quebec mapset installed on the sc card I get the following:
3.67 GiB free of 7.24 GiB
There are 2 maps available in 3 files, total 3.18 GiB
Number of map segments: 553

G-disk (G:\) in GPSMAP 64st
18.97 GiB free of 28.96 GiB
There are 5 maps available in 5 files, total 9.99 GiB
Number of map segments: 2003

Pretty close to the 3k limit!

I will have to experiment with other cards and map sets.  Btw, this is great!  I really appreciate the help.  I'm on my way to becoming a Power User!


Happy to help. Remember, you need to include any maps installed in the GPS internal memory in the count. So your 2000 segment card actually might be at the limit.