A simple tool to force a particular FAT order of files in a directory is http://www.anerty.net/software/file/DriveSortijabbott wrote: ↑Wed Mar 07, 2018 11:01 pmThey are displayed in raw directory order. If you delete files, it leaves empty spaces in the directory that can be filled by new files. (It's a little more complicated than that, because with VFAT, directory entries are variable length. So when a new file is added to the directory, it needs to find a large enough gap in the directory, or append to the end of the directory.)
I think you can force a particular display order by deleting all the files in the OFFIMG folder and adding them back one at a time in the order you want them to be displayed. To save flash wear, it would be better to rename the OFFIMG folder to OLDIMG, create a new OFFIMG folder, and move (not copy) the images one at a time from OLDIMG to OFFIMG in the desired display order.
I don't think it rewrites the files, only the FAT table. I use this to sort music files on USB-sticks for old mp3 players that uses FAT file ordering.