On Sun, 19 Apr 2009 17:57:53 -0700, "Anthony K."
-removeme put finger to keyboard and
composed:

It's apparently not a matter of just gutting a 3.5" FDD USB drive and
connecting a 5.25". The controller will likely not be able to talk
5.25",...

SMSC had a USB bridge chip (USB97CFDC2-01) that supported "640K, 720K,
1.44M, 1.2M Windows 98 J, and 1.2M NEC DOS 6.x Formats":

http://www.keil.com/dd/docs/datashts...usb97cfdc2.pdf

Its USB VID and PID were 0424 and 0fdc. Perhaps you could determine
the VID and PID of the bridge chip in a prospective USB floppy
enclosure by interrogating it using UVCView (Microsoft), or an
equivalent Linux or MAC utility. Then search for a datasheet.

If the box has Windows 98SE drivers, then the VID and PID should
appear in its INF file.

In fact, according to page 5 of the driver installation instructions,
the Sabrent model SBT-UFDB USB floppy uses an SMSC chip:

http://www.micropactech.com/drivers/...e%20Driver.pdf
http://www.tigerdirect.ca/applicatio...9134&CatId=287

Unfortunately it is USB powered (500mA max) and does not appear to
support transfer rates less than 500Kbps.

- Franc Zabkar
--
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