Remote job submission from PDP-11

Bob Smith bobsmithofd at
Thu Oct 8 17:28:07 CDT 2020

Hey Dave,
I think the two guys working the tools originally were Bob Rosenbaum
and Harvey Schlesinger.
You are pretty much correct on the diffs between KMC and DMC. KMC had
180NS instruction time, and larger ram than the DMC iirc on that
I worked on both with Remi Lissee.
I designed the DMC line units, and the line united we used in the
Autodin II system - CSS took over the cards.
DOn't forget about the Triax with special modem built i for DMC11.
Those were done for JPL and some others...
The COMM IOP for Autodin II handled a separate set of cards, sync or
async - supporting SDLC/BiSYNC,and Isoc.
After the design of the Autodin chips were done - 2652/5025 - the spec
was changed to add a couple of new CRC requirements,
mathematically insignificant but algorithms designed by Georgia Tech
and Cartwr  was in office.... So, Zereski and I did a drop in chip
that would add that algorithm set in addition to the nrom VRC/LRC/CRC
one we had already done i nthe chips - 2652 was mine, 5025 was Frank
bob smith
badge xxxx

On Thu, Oct 8, 2020 at 3:11 PM Dave Mitton via cctech
<cctech at> wrote:
> >Date: Wed, 7 Oct 2020 11:29:43 -0700
> >From: Glen Slick <glen.slick at>
> >Subject: Re: Remote job submission from PDP-11
> >
> >On Wed, Oct 7, 2020 at 11:04 AM Paul Koning <paulkoning at> wrote:
> > >
> > > > On Oct 7, 2020, at 12:06 PM, Glen Slick via cctalk
> > <cctalk at> wrote:
> > > >
> > > > ...
> > > > I was curious about this DEC M8704 DMS11-DA that sold cheap a few days
> > > > ago. It has eight SMC COM5025 "Multi-Protocol Universal Synchronous
> > > > Receiver/Transmitter USYNR/T" chips:
> > > >
> > > >
> > > >
> > > > Apparently it can't do anything on its own. It needs to be connected
> > > > to a UNIBUS through a companion KMC11 processor board, which might not
> > > > be too common if someone wanted to put together a working
> > > > configuration.
> > >
> > > That model number isn't familiar.
> > >
> > > A KMC-11 is simply a microprocessor that sits on the Unibus and
> > does Unibus cycles to another device on behalf of the host.  The
> > idea is to offload operations so the host can ask for block
> > transfers and the KMC does the individual character I/O operations needed.
> > >
> > > That said, it clearly is not correct that "it can't do anything
> > on its own".  The KMC-11 reaches into the device via its Unibus
> > CSRs.  If you can find a description of its operation, or reverse
> > engineer it, you can clearly write a device driver for it that
> > doesn't rely on a KMC-11.
> > >
> > >         paul
> >
> >Well it does appear that M8704 DMS11-DA "can't do anything on its own"
> >directly through the UNIBUS. From a quick visual inspection it only
> >has power and grant continuity traces on the card edge connectors. The
> >connection to the controlling KMC-11 is through the 40-pin Berg
> >connector. So without a KMC-11 an alternate interface through the
> >40-pin Berg connector would be needed.
> My first job at DEC was to release the KMC-11 Programmer's Tools
> support for RSX-11.
> (I didn't write them from scratch, two other engineers did that, but
> I did do final debug and QA)
> We provided two firmware kit products; the CommIOP-DUP and DZ, which
> controlled the DUP-11 and DZ-11 respectively.
> The KMC-11 could do NPR bus transfers to/from the devices, and the
> CommIOP-DUP firmware could do Bisync or X.25 type framing so that you
> got an RSX-11 driver with a packet interface, vs byte at a
> time.   The CommIO-DZ firmware provided various customizable state
> driven things as you might want for a line driven terminal
> concentrator.  I'm pretty sure the packages came with the "source"
> code, so you could customize it if you could understand it.
> The DMC-11 did DDMCP support and was basically a KMC with ROM in the
> control store.  And it did use that external connector to the
> proprietary network interface card, DMC-11DA.
> In later years, I wrote and released a KMC Tools package for
> VMS-11.  That came with a VMS DMA LP-11 line printer driver I authored.
> I don't remember if the CommIOP tools were supported.  Some VMS
> engineers didn't like these products. (another story)
> (That didn't stop the Lab products guys in Marlboro from using them
> for their applications)
> There was a later version called the KMC-11B which doubled the memory
> and probably ran faster too.  It was the same board as the DMP-11
> product which was an improved version of the DMC-11.
> These were quad Unibus boards.  In the Q bus world, there was a 6502
> based I/O processor card developed (outside of Networks) (as one-chip
> micros became available) as well.
> I have a KMC-11 Programmer's Manual here... I think you'll need a
> print set to figure out that connector.
> Dave.

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