In message <199909131614.JAA16187@lestat.nas.nasa.gov>,
Jason Thorpe writes:

>On Mon, 13 Sep 1999 15:52:44 +1000 
> Simon Burge <simonb@netbsd.org> wrote:
>
> > Are the mmeye and evbsh3 different enough to warrent their own top-level
> > sys/arch directories?
>
>No different than how `amiga' and `hp300' are separated, really...

They have different MMUs.  I guess the external interrrupt-controller
is the sticking point?