In some Asus BIOS files, you can see comments like this. This
comment is from a P4C800-E BIOS. Usually these comments appear
on the right hand side of the BIOS screen, when you are changing
"USB devices less than 530MB will be emulated as Floppy and
remaining as hard drive. Forced FDD option can be used to
force a HDD formatted drive to boot as FDD (Ex. ZIP drive)"
It means there can be various emulation modes in there.
You'll just have to experiment like everybody else. It
is not like there is a "one size fits all" procedure to
As I understand it, there are several FAT variants which
change what the USB device looks like. If it was going to
boot like a floppy, it likely needs a FAT that looks like
To find comments inside a BIOS, I use AMIBCP75 to extract
BIOS modules (for AMI BIOS), while for Award BIOS now, in
some cases I'm having to use a hex editor to snip portions
of the BIOS file out, then decompress with LHA.exe . BIOS
are generally compressed, so simply looking at a BIOS file
with a hex editor won't tell you anything. If AMIBCP75 won't
open a file (and there are some Asus AMI files produced with
tools later than 7.5), right now I'm screwed.
Using my favorite search engine, with terms
"usb flash boot asus", I can find web pages like the following.
Some of the recipes have an element of danger to them, so
use a spare (scratch) disk to boot the computer while
experimenting, disconnecting any data drives that you don't
have backups for. That is just in case some poorly written
tool decides to format the wrong device :-(