I thought that when loading g2Bluechart images onto a unit, it could/would only "see" one gmapsupp image file.
On my 76CSx I have been renaming the images from a descriptive name to gmapsupp.img and back and forth depending on what chart image I wan tto use. It has worked fine so far.
But I started to load some of the g2 Bluechart Vision images onto my Oregon 400 and saw and rememberd that I have a gmapsupp.img BlueChart loded on the INTERNAL memory of the 400 and also another gmapsupp.img loaded onto the MemCard.
They worked fine and in the map options menu, the different chart names were diaplayed and gave me the option of enableing or disableing each of them.
Now as I said, these wer REGULAR g2 Blucharts and NOT the "Vision" charts.
So did it work becasue they were not Vision charts, or is it becasue I have two types of memory location to store the images...... internal memory or the Micro-SD memory card ?
I am loading a g2 Vision Bluechart onto the unit now to see what happens.
And as I remember, you can also have more than one gmapsupp.img file on memory card. You can remember them like gmapsupp1.img, gmapsupp2.img. Works on my Oregon 550.
With Oregon devices it is possible to use every name you want for your map files (ending with .img).
Transferring maps using MapSource or MapInstall will always produce maps named gmapsupp.img, so you have to rename them (Explorer) before you send the next to the device / memory card. If you have ready map images downloaded, you just can put them on your device / memory card using Windows Explorer.
I use a 8GB memory card with about 10 map files on it with my Oregon 400t. On the internal memory I have loaded some OSM maps beside the original maps coming with the Oregon 400t. So all together ther are about 20 maps in my Oregon, all working fine. The only restriction is, not to have more than 4000 map tiles on the system in total (number of tiles you can find out using gmaptool). So just enjoy live with your Oregon!
Btw it does not matter which kind your maps are of (G2 / Vision / NT etc.)