Boot from usb

Hi
Env : Pc Asrock Mother board ,floppy disk drive ,TSST SHS223C dvd rom
Prb : Bios does not support boot from this (damned) DVD rom
and does not support boot from usb
to bypass i have to open pc and connet another dvd drive
seraching internet i find this program
plob 5.0.15 ...
i create an floppy image and i boot from floppy succesfully
but when i select usb device it hungs (tried also alt-u)
it seems ehci driver loaded with plop does not function
looking in the plop site,many users had the same problems
Is there an OPEN SOURCE program doing the same function ?
thanks in advance for the support
Maurizio