Daystar's site definitely has the driver. It's called PowerCentral. 
Here's the URL:
ftp://ftp.daystar.com/daystar.com/Upgrades/Turbo040.PowerCache/

If you use a normal kernel, you have to disable the cache before you boot 
into NetBSD.

Or, there is a power-cache enabled kernel. Here's a clipping from the 
anoucement email:

	---------------------
	For the brave, there is a new Daystar test kernel at:

	ftp://cpre1.ee.iastate.edu/pub/netbsd/netbsd-daystar#2.tar.gz

	It should be more robust than the previous kernel.  It
	was compiled from current source as of Apr 28 (or sometime
	near there)
	----------------------

I've been running it for a while. I haven't had any problems with it. It 
won't blow you away, but it will be noticeably faster. I don't know if 
there is a newer one.

If you use this kernel, you don't need the daystar driver software; the 
kernel enables the cache itself.

-1LT Avram Dorfman
HQ USAF Network Management
permanent email address: avram@pobox.com