Re: New Vax - future directions :-)

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2021-07-07 15:03, Paul Koning wrote:
> > On Jul 7, 2021, at 8:02 AM, Johnny Billquist <bqt%update.uu.se@localhost> wrote:
> >
> > On 2021-07-07 13:37, Anders Magnusson wrote:
> > > Den 2021-07-07 kl. 11:37, skrev Hans Rosenfeld:
> > > > > ...
> > > > And, can we perhaps get a PDP11 compatibility mode, too? Like the one
> > > > early VAX-11 models had? Please? :)
> > > >
> > > > Thanks for breathing some life back into the VAX, and into port-vax.
> > > > This is so amazing on so many levels. :)
> > > Hm, I haven't thought of that before, but it might be quite trivial to do that.
> > > Almost no extra hardware, just a separate match for the microassembler.
> >
> > I'd be a little curious on why anyone would want it, though. (Even me, being a PDP-11 fanatic, isn't that interested in this compatibility mode...)
>
> It allows running early VMS releases.

Ah. True. But would you even try to do that on some new FPGA 
implementation of a VAX?
Then you'd have to pretty faithfully implement all peripherals and other 
details of the VAX-11 machines. All the internal registers specific to 
that machine, and so on...
If I wanted to run old VMS, seems like simh would be a simpler way.

  Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
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