Adaptec USB2Xchange

I have reason to use a USB to SCSI adapter under FBSD.  I have a USB2Xchange
from Adaptec, but (as usual for adaptec) it requires a firmware load, which 
appears harder in usb than in PCI.  Does anyone know how to do this?  (Should 
we have a generic firmware loader similar in concept to the ndis converter?)

A not-as-preferred alternative would be a PC card scsi unit; this won't
work on the desktop computers, though.

For my immediate application (streaming tape) I could tolerate a userland 
driver under ugen.  For disks this wouldn't work without a more general 
kernel block-device structure (or a userland link back to the cam/xpt layer,
analogous to the tunnel net driver, which couldn't be *too* hard and could 
be desirable).

Kernel attach message is:
ugen0: Adaptec product 0x2002, rev 2.00/1.00, addr 2

My kernel has ugen/umass/uhid/ums/ucom/uplcom/umodem compiled in, so
this (which should show somewhere?) isn't being recognized.

1. Has anyone else tried this (or wanted to...)?
2. Absent a way to use this device, what would work (I know about slimscsi;
   it is less desirable since I can't use it on my desktop systems)?

-- Pete