Yes, my apologies. You're right of course it's "00" not "FF". I posted from my phone without checking and mixed up how the extra unpopulated region space shows in a hex reader comparing, for example, fw_all.bin with dumped 14.bin. How i should have said it is this: It should be indicated by 00s following the series of FFs at the end of the 14.bin file. My 'experience' is limited to the basics and to older devices too, i.e those with non-encryted firmware. Although i do understand quite well how most Garmin devices work, because i'm not a programmer i may not be of any great help in your current mission. However i'll follow this thread with interest regardless. Good luck with your efforts.