Re: New Vax - future directions :-)

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

On 2021-07-07 13:37, Anders Magnusson wrote:
> Den 2021-07-07 kl. 11:37, skrev Hans Rosenfeld:
> > On Sat, Jul 03, 2021 at 03:46:00PM +0200, Anders Magnusson wrote:
> > > Convenience:
> > > Even though there are 288 instructions, a few are missing that would be
> > > nice.  For example;
> > > - Unsigned mul/div.  Vax only have signed.
> > > - logical shift right.  Vax have EXTZV, but it is an unneccessarily
> > > complicated instruction.
> > > - AND.  Vax have BIC instead, but that (almost) always require a 
> > > complement
> > > as well.
> > 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...)

> I'l keep it in mind.  Does not have high priority though :-)

Obviously not the most urgent thing right now. I suspect an MMU is high 
on the list, though.

  Johnny

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