Disk mirroring with 'dd' and (expletives) USB ISDN modem

[Chris Martinus]

For years I have backed up my FreeBSD systems using tcopy.  I use removeable disk trays for fast recovery.  All disks are configured bus master and are connected to different IDE controllers.
 
tcopy /dev/ad0 /dev/ad2
fsck -y /dev/ad2a
 
works just great!  There's just a whinge from tcopy when it tries to rewind the disk (tcopy = 'tape copy').  The only caveat is that the drives should be identical.
 
Now for my question.  I have been trying to get a USB ISDN modem (Microcom ISDN USB Travel/C) hooked up.  Currently using FreeBSD 4.8.  After googling etc I found references to "device umodem" & "device ucom".  Tried compiling them in, but nothing other than the ugen driver finds the modem.
 
The modem never even powers up, though it works fine with Windoze.  Can anyone point me in the right direction?
 
Chris Martinus