There was some discussion on that a while back on axp-list@redhat.com
	Apparently there is some bit in the cpu (which Digital in all its
	wisdom decided could be used to distinguish between NT and UNIX
	such that in one version only ARC - NT would work.

On Mon, 6 Oct 1997, Ted Lemon wrote:

> 
> BTW, the reason why I was working on an SRM replacement even though I
> had the PALcode developers kit is that the version of SRM that's
> included in that kit will not run on 21164-P7 parts, even though it
> will run on an identically-configured motherboard with a 21164-P6.
> Since the source isn't included, there's no way to know why it didn't
> work.
> 
> 			       _MelloN_
>