Paul, i've looked at the softpack and if the UCODE.IMG is corrected, it should be possible to burnt to a CD and boot from it. Such methods have been used by linux guys to update bios and microcode on their systems for some time so not sure i agree XP+floppy is the ONLY way...
Clarkey, it's trivial to fix the UCODE.IMG and burn it to disk and then boot from that CD. Surely such is quicker than finding old HDD, Floppy drive and blank floppy. Why not try it and let us know how it goes?