USB display?

[Alan Evans]

Hello All!

The boss dropped one of those DisplayLink USB display adaptors on my
desk today, and I'm drooling at the prospect of having a third monitor
on my devel machine.

The machine is running F14 at present and the kernel doesn't know what
to do with the adapter when I plug it in. The system log indicates
that something with a particular vendor ID is plugged in but nothing
else. These things are pretty new so I booted a F16 Live CD and the
situation is much better. The system log enumerates available
resolutions, allocates a framebuffer, and registers the udlfb driver
for it. The monitor, for its part, presents a lovely solid green
screen. But Xorg doesn't seem to care; and my desktop is still limited
to my current two heads, with nary a hint of another display device
available.

This all seems so close I can taste it. But I don't know what to try.

In the old days, I might have tried to jack with the xorg.conf file,
but that seems to have vanished somewhere along the way while I wasn't
looking. Has anybody got one of these things to work? How can I tell
Xorg that there's another display out there, longing to be used?

-Alan