DEC MKA11 and/or M8261/M8163

[Jacob Ritorto]

there were links to pics of an 11/74 on the list a few months ago, weren't
there?

On Sat, Feb 14, 2015 at 1:59 PM, Paul Birkel <pbirkel at gmail.com> wrote:

> PS: Just noticed the Memory options in Table 1-3.
>
> MKA11-AA is Single Port Memory and uses the Single Port Jumper Card.
>
> MKA11-BA is Dual Port Memory and uses the Multiport Multiplexer.
>
> MKA11-UA is Single port upgrade kit and includes a pair of port-buffers and
> one multiport multiplexer :->.
>
> MKA11-UB is Multiport upgrade kit adds another pair of port buffers; you
> can apparently do this twice.  So I guess one Multiport Multiplexer handles
> up to four ports.  Now ... how does two sets of six-bits fit into that
> scheme?
>
> M8164 isn't mentioned anywhere, so I guess that's simply a general-upgrade
> replacing M8159 that applies to either MK11 or MKA11.
>
>
> On Sat, Feb 14, 2015 at 1:50 PM, Paul Birkel <pbirkel at gmail.com> wrote:
>
> > So ... I should have stretched my mind a bit more in the space of "stuff
> > like an 11/70 but which is not an 11/70 ...".  Encountering even a bit of
> > an 11/74 was simply not something that I ever considered.  Thanks for the
> > pointer Johnny!
> >
> > Looking at the preliminary Docs, Figure 1-1, where a two-processor
> > configuration is laid out, with two MKA11, it appears that they have
> their
> > ports cross-wired and then driven from a panel-control of some sort.  So
> > there's 6-bits for MK0A/MK1A, and then a separate 6-bits for MK0B/MK1B
> (see
> > earlier response to Eric about the connector arrangements).  Not at all
> > clear to me how that wiring relates to the description in 1.4.2.  Need to
> > think about this some more ...
> >
> > It seems then that the Field Guide has both of these modules
> mis-assigned,
> > and the second misnamed.
> >
> > I wonder if the relationship between the M8163 and M8164 is an either/or
> > and they go into the same slot given that Table 1-1 mentions only a
> single
> > Multiport Multiplexor (M8162) and the naming in Table 1-3 for the M8163
> is
> > "Single Port Jumper Card"?  I guess that's what you're thinking as well.
> >
> > What is the purpose of the "panel" Port Controllers, given that they seem
> > to be not connected to any control signals from the CPU? (Figure 1-1)
> >
> > Does the "T" in the symbology in the Figure perhaps indicate
> > "Terminator"?  If so, that seems to suggest that the signaling is out one
> > control, into the second and then off "through" a terminator to the panel
> > Port Control?
> >
> > Honestly, Figure 1-1 doesn't look to me like a shared-memory arrangement
> > ... so I'm probably misinterpreting some of those lines at the moment.
> >
> > Thanks for all of the additional clues and pointers guys!
> >
> >
> > On Thu, Feb 12, 2015 at 5:24 AM, Johnny Billquist <bqt at update.uu.se>
> > wrote:
> >
> >> On 2015-02-11 20:55, Eric Smith wrote:
> >>
> >>> On Sat, Feb 7, 2015 at 7:25 AM, Paul Birkel <pbirkel at gmail.com> wrote:
> >>>
> >>>> I don't understand the role of the M8162 "Port MUX A module" and M8163
> >>>> "Port MUX B module" that the field-guide claims to be part of the
> MK11.
> >>>> They aren't part of the MK11 as far as any documentation that I've
> read
> >>>> regarding it. [...]
> >>>> Do these modules really belong to the MKA11, rather than the MK11?
> >>>>
> >>>
> >>> The MKA11 was the multiported version of the MK11, intended for
> >>> multiprocessor (11/72 and 11/74) systems. it makes sense that it would
> >>> have some "port mux" modules, though I've never seen any documentation
> >>> on it.
> >>>
> >>
> >> I don't think that 11/72 is a valid designation. All documentation I've
> >> read only calls it an 11/74, no matter how many CPUs you have.
> >>
> >> You can find documentation on the MKA11 in the 11/74 documentation.
> >> (See http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1174/
> >> EK-70MP-TM_PRE_1170mp_Prelim_Technical_Manual_1977.pdf)
> >>
> >> And in there, you can find that:
> >>
> >> M8162 is a "Multiport Multiplexor Module"
> >>
> >> and
> >>
> >> M8163 is a "Single Port Jumper Card".
> >>
> >> So yes, both of these cards are for the MKA11.
> >>
> >> I would guess that you use the M8163 if you have an MKA11 but just a
> >> single CPU.
> >>
> >>  Reportedly some 11/70 systems were sold to AT&T with the KB11-CM CPU
> >>> and MKA11, apparently just as a way to use up the hardware that was
> >>> built for the cancelled 11/74.
> >>>
> >>
> >> I've heard similar. And also that CPU cards for the 11/74 were installed
> >> in 11/70 systems. The differences don't matter for normal operation,
> and it
> >> will work like a normal 11/70. You can detect if differences if you try,
> >> but the system will work like any other 11/70.
> >>
> >> Only a few CPU modules differ between an 11/70 and 11/74 anyway.
> >>
> >>         Johnny
> >>
> >>
> >
>