Okay, a little bit more info:

The modem, when it's in ISAPnP mode, is seen by Windows on IRQ 10.
NetBSD sees it on IRQ 4.  But at that point, IRQ 4 is already assigned
to com0, the built-in serial port.  This doesn't change, regardless of
whether I assign IRQ 4 to legacy ISA, and regardless of whether I
enable "PnP OS."

NetBSD's just reading the IRQ assignment from the BIOS, right?  But it
sure doesn't seem like the BIOS is assigning 4 to the card.

If I put the card on (DOS) COM1, and disable the on-board COM1, I get
a panic "cannot share level-triggered with edge-triggered."

This is weird.

Chris

-- 
-----------------------------------------------------cjones@math.montana.edu
Chris Jones                                          cjones@honors.montana.edu
           Mad scientist at large                    cjones@nervana.montana.edu
"Is this going to be a stand-up programming session, sir, or another bug hunt?"