RL02 version of UNIX6?

Josh Dersch derschjo at gmail.com
Fri Feb 3 15:28:43 CST 2017


On Fri, Feb 3, 2017 at 1:17 PM, Paul Koning <paulkoning at comcast.net> wrote:

>
> > On Feb 3, 2017, at 4:07 PM, Josh Dersch <derschjo at gmail.com> wrote:
> >
> > On Fri, Feb 3, 2017 at 12:31 PM, Paul Koning <paulkoning at comcast.net>
> wrote:
> >
> >>
> >>
> >>
> >> I'm not sure there is one.  DEC OS designers typically would assume that
> >> they are dealing with non-broken systems.  Systems with MMU all have
> EIS...
> >>
> >
> > Is this actually true?  I've been working on getting my PDP-11/40 running
> > recently, and I don't recall anything in the documentation indicating
> that
> > an EIS was required if you had an MMU installed.
>
> What I meant is that the 11/40 has EIS standard, according to the PDP11
> architecture handbook.  So an OS that depends on MMU would be designed for
> 11/40, 11/45, etc. all of which have EIS.  And since EIS instructions are
> quite helpful they will be used.  Not necessarily MUL, in a kernel, but
> definitely SOB.
>

EIS was an option on the 11/40, it was not standard.
https://pdos.csail.mit.edu/6.828/2005/readings/pdp11-40.pdf, section 2.4.

- Josh



>
>         paul
>
>
>


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