> How much work would it take to port NetBSD to SGI machines which are
> ARCS-compliant? 

I'm not sure. Does the machine have ARC BIOS?
Currently, all ARC BIOS function cannot be called after kernel starts.
(i.e. kernel cannot call ARC BIOS function)
So, all device driver should be written.

> I understand NetBSD/pica is to become NetBSD/arc?

yes.
--
soda