Hi
I looked at the wiki
http://en.wikipedia.org/wiki/Floppy_disk
but I could not see the power connector for 5.25" drives I suspect it uses the standard molex connector with 5v + 12v
(red black black yellow wires) while 3.5" floppy disks only use 5V and a different connector.
The ribbon data cable uses different connectors for 3.5" & 5.25" floppy drives
5.25" includes high density 1.2 Meg (1985) and 360K (1982) versions.
I still have a combined 5.25"+3.5" version sitting in a cupboard should I ever need it but my current motherboard does not have a floppy controller
The chance of getting USB to work is low to zero.
Do you have a 5.25" 1.2M drive to work with ?
regards
Mike Barnes