Hi Mike-
I followed this method: http://failverse.com/creating-a-non-standard-size-bootable-floppy-image-for-pxe-boot/

That worked, the rest was just making SeaBIOS (at the time) try to read them, as per the discussion.

FWIW I managed to increase my ROM chip size from 8 to 16MB and stuff it with coreboot + Grub (which loads either SeaBIOS, Tianocore or a stripped-down TinyCore Linux). Works great, no need for floppies.

Good luck, please update with your results once you find something interesting / useful!


On Fri, Apr 3, 2020 at 10:34 AM Mike Banon <mikebdp2@gmail.com> wrote:
Rafael, please could you share a working method of expanding a floppy
from 1.44MB to i.e. 2.88MB ?

I'm back to this issue and noticed that popular Linux tools (i.e.
gparted with libparted, fatresize, etc.) weirdly do not support
resizing a FAT12 filesystem which the floppies have. Manually
increasing the number or sectors with a hexedit - 0x13/0x14 bytes from
0x0B40 to 0x1680 and 0x18 byte from 0x12 to 0x24 - also didn't work
for me (but I just learned about FAT structure and may be missing