Subject: Re: no MP support on 785?
To: None <port-vax@netbsd.org, is@netbsd.org>
From: Anders Magnusson <ragge@ludd.luth.se>
List: port-vax
Date: 10/07/2001 16:20:08
> Ragge,
> 
> Long, long ago, you wrote:
> 
>  The VAX 8350 system is probably the slowest multiprocessor system              
>  that NetBSD will ever support; each CPU does about 2VUPS (~2MIPS) :-)          
> 
> No 785? hm, I know the other CPU doesn't have access to I/O, but is this a
> Problem? Or is the memory non-shared?
> 
I assume you mean the 782, 785 is just a hotted-up 780 :-)

The 782 is in principle two 780's, each of them with separate IO devices,
separate memory etc but with some shared memory (in a separate box) to
make the two machines to be able to communicate with each other. The
shared memory is intended only to send messages between the two machines,
it's slow and normally very little memory. Its intended usage is something
like the SYSVSHM that communicate between processes.

So, the 782 machine is just two "normal" single-CPU machines that can talk
to each other faster than over network. I know Mach was ported to that type
of VAXen but I think that was only for testing purposes to see if the Mach
concept worked on it. It wouldn't be realistic to try to port NetBSD to it.

-- Ragge