In the end I created a second partition and put my payload file there. That
worked, but before that I tried to extend the FAT12 partition with gparted
but my copy (from Ubuntu 21.04) objected and said that FAT12 is no longer
supported. The Wikipedia page says that FAT12 goes back to the early 80's,
I've installed FreeDOS 1.3-RC4 with FD13LITE.img on a 4GB USB drive. This
works and I can boot it just fine, but the primary partition uses FAT12 and
is 97% full. I would like to expand this partition with gparted, but that
no longer supports FAT12. Can I ask what the rationale is for using FAT12?
