> 
> The machine is a VAXstation 4000-90 running NetBSD 1.5. I thought that
> NetBSD emulates missing instructions? 
> 
Well, not _all_ instructions that can be missing. There are lots
of insn't that could be added, feel free to do it :-)
Anyway; regarding modf(), the problem is that modf uses emodd, and 
that emulation code was written a while ago by bjc@openbsd but I was
lazy, so it wasn't checked in. Now I've done it, so you should be 
able to test it with a new kernel from 
ftp://bakfull.campus.luth.se/netbsd/netbsd
or check it out from the source tree.

-- Ragge