On Fri, Feb 3, 2017 at 12:31 PM, Paul Koning <[email protected]> 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. (On the other hand, the MMU docs indicate that the Stack Limit Register must be installed if an MMU is present, though I haven't looked into why this is the case). For the record, my system currently has the MMU, but lacks an EIS (still trying to track one down). It may be that DEC never shipped an MMU without an EIS in an 11/40... - Josh
