Quote Originally Posted by Santosan View Post
Assuming you are refering to a Garmin device, you can use the internal memory to copy two maps, one named gmapprom & the other gmapsupp. You can use your SD to copy two more files one named gmapsupp & the other gmapsup2 not gmapsupp2 Garmin won't recognize it. If you want more info about mapset naming you can find an interesting mapset naming guide here: (link removed)
On my Nuvi 255W the second map on SD card worked only with the name gmapsup1, not gmapsup2, so anyone interested could try this name also.
Thanks however for the tip on naming the map gmapsup with just one p at the end, because all other variants failed.