Re: NetBSD in SIMH vax with 512 MB RAM

[Dave McGuire <mcguire%neurotica.com@localhost>]

On 3/7/23 12:55, Anders Magnusson wrote:
> > > The P0/P1/S0/S1 space is in virtual space.
> > >
> > > The 512M is physical memory. Physical address space is a total of 
> > > just 1G, with half dedicated to memory, and half to I/O space.
> > >
> > > So 512M is the absolute maximum the machines can have. And there is 
> > > some problem with this in NetBSD.
> >
> >   This must be model-specific, somehow?
> The I/O space starts at 512MB.

  Yes, ah, so memory must be discontiguous in some machines.  The 
VAX-7000 at LSSM has 1.5GB of RAM.  I hadn't thought about how that 
would work until this thread.

             -Dave

--
Dave McGuire, AK4HZ
New Kensington, PA