Has anybody gotten B&W video to work on Quadra AV's?

I was test booting on a Q840AV yesterday with a -current kernel and it
booted up, made a horrible screech, and displayed the last line of
the message just before the device initialization.

Is this where the "madhatter" patch is supposed to be applied?

A C650 booted great even in 16 bit mode so I suppose it is :)

The reason I ask is that I was hacking on the AV's to figure out more
of their video and I wanted to know if I can even boot a test kernel
on them.

If the madhatter patch does what I think then I might be able to make a
more general solution.