[Simh] DECnet for TOPS-10

[Johnny Billquist]

I did some poking around, and found a little information from MRC. I'm 
sure more can be found on the net. Too bad he's not with us anymore...

Anyway. Here is what he wrote 8 years ago 
(http://alt.sys.pdp10.narkive.com/ceLh26Dc/decnet-for-ks10-tops-20-only):

====
Mark Crispin               8 years ago
Post by Mark Hittinger
 > Phase IV did bring ethernet and extra routing stuff - I am not sure 
that the
 > KS-10 could do this because of memory limitations. I remember 
something about
 > decnet being moved out of section 0 because of the memory issue.
 > So I'm pretty sure its phase III, end node, compiled into section 0, and
 > using the dmc-11 interface.

I did Phase IV DECnet support for the KS in TOPS-20 4.2 (what? You never
heard of TOPS-20 4.2?).

It was a major squeeze to get it to build in a single section, and that
was just using the KMC11. I also had to reduce the size of the KMC11
packets.

The router support was there, and if a DEUNA driver was written it could
use it; but memory was seriously limited by this.

-- Mark --
====

	Johnny

On 2013-04-14 14:31, Johnny Billquist wrote:
> On 2013-04-14 02:18, Timothe Litt wrote:
>>> Did I remember wrong in that I thought I had seen something from MRC
>>> in the past where he said he had managed to get phase IV for TOPS-20
>>> running on a KS?
>> MRC may well have reconstructed a V5 monitor for the KS from the
>> sources, but that's not DEC product.  And unless he did a lot of work,
>> it would have been an interesting toy, but not product quality.
>
> I don't think it was production ready, but I seem to remember he did it
> sponsored by DEC. But it never got shipped. Cancelled in the end, for
> one reason or other. But I think it was running just fine.
> But this is all from memory, and I might very well have things wrong.
>
>> Support for TOPS-20 on the KS ended with V4.1 (Phase III).  The most
>> pervasive changes in Phase-IV were a consequence of supporting broadcast
>> media.  DECnet Phase IV was initially developed on a KS with a 3-Com
>> ethernet card, as the DEUNA took too many slots, and the KLNIA wasn't
>> ready.  (The DECnet, LAT and SCA modules were ported to TOPS-10; some of
>> the TOPS-10 changes went back into the DECnet group's sources.)  As the
>> DECnet code grew, more modules were moved into extended sections,
>> including the SCA (CI) and cluster drivers.  It was barely possible to
>> boot V5 on the KS if you cut back on a lot of configuration parameters,
>> but DEC never shipped it because there wasn't enough exec address space
>> left over (or resources) for a reasonably configured/responsive system.
>> It was held together to support DECnet development for quite a while,
>> but over time the dependencies on extended addressing grew.  Once the
>> KLNIA was stable, the DECnet group abandoned the KS, as did the monitor
>> group.
>
> Interesting stuff. I admit to not having opened a KS that many times,
> but was Unibus space really that scarce? I mean, the DEUNA is just two
> cards after all. (Using two slots.)
>
>> TOPS-20 development decided to stabilize the KS at 4.1 rather than
>> invest in making 5.0 production quality on the KS.  Since support was in
>> another group, they didn't bear the costs.  A few people in the support
>> group had 5.1 running on the KS as a support tool (didn't want to get
>> rid of their KS system, as it was a lot cheaper in floor space, power,
>> and maintenance than buying/running another KL.)  But that was
>> scaled-down & not product quality. I don't recall them succeeding (or
>> even putting much effort) at later versions of TOPS-20.  The leftover
>> tracks in the sources would probably be the basis of MRC's work.
>
> I know that TOPS-20 never went beyond 4.1 on the KS. Sad, but probably
> understandable. Wasn't it that the KS actually have KL style extended
> sections, but there are only two sections on the KS?
>
> I don't know when MRC did his work, or what he had available. But it
> don't sound unreasonable that he'd use what you had already done.
>
>> I made a different call for TOPS-10.  I updated the KS microcode to
>> support the version of KL paging that TOPS-10 used (but still a single
>> section), and made Phase IV work.  JMF & I then came up with the
>> slight-of-hand to create an alternate address space for DECnet, allowing
>> TOPS-10 to also support a reasonable number of users.  Presented with a
>> fait-accompli, product management saw the benefits and allowed us to
>> ship it.  Happy customers.  And we only had to support one version of
>> the monitor through end-of-life of the 36-bit product line.
>
> Yeah. I even used Tops-10 V7.02 on a KS. Thanks. :-)
> (Don't think I used 7.03 though.)
>
>>>> TOPS-20 can participate in a modern network.
>>> More or less. There are some restrictions.
>> Yes, but in this context, they're not significant.  TOPS-20 Phase-III
>> will talk to a Phase IV system.  Routing is different; the Phase-III
>> node doesn't know about areas, and (obviously) anything new in Phase-IV
>> doesn't magically appear in the Phase III implementation.  But Phase-III
>> routers and end nodes can happily co-exist with Phase-IV on serial
>> links.  NCP works.  And PMR can be used to allow the Phase III nodes to
>> communicate across areas.
>
> Phase III nodes can't directly talk with nodes in the same area either,
> if the other node have an address > 255.
>
>      Johnny
>
>>
>> This communication may not represent my employer's views,
>> if any, on the matters discussed.
>>
>> On 13-Apr-13 19:05, Johnny Billquist wrote:
>>> On 2013-04-14 00:39, Timothe Litt wrote:
>>>>> That sounds like we can get DECnet on TOPS-20 on SIMH, if so that
>>>>> would be
>>>>> really great!
>>>> Yes.
>>>>> Which phase(s) does TOPS-20 DECnet support on the KS?
>>>> Phase III.  Because it was so large, Phase IV used extended sections
>>>> (addressing), which the KS doesn't support.  I used slight-of-hand to
>>>> make Phase IV fit into TOPS-10 on the KS10.
>>>
>>> Did I remember wrong in that I thought I had seen something from MRC
>>> in the past where he said he had managed to get phase IV for TOPS-20
>>> running on a KS?
>>>
>>>> But Phase III will connect to a Phase IV node, so TOPS-20 can
>>>> participate in a modern network.
>>>
>>> More or less. There are some restrictions.
>>>
>>>     Johnny
>>>
>>>>> Adding DMR support was on my list, but I haven't done it yet. I'll see
>>>>> if I
>>>>> can get the KMC/DUP code in and then do DMR, but it may be a while
>>>>> before I
>>>>> get time.
>>>> That would be super.  It looked like your code has some hooks for DMR,
>>>> but is incomplete.  Given that you don't actually do DDCMP, the
>>>> differences should be small.
>>>>
>>>> --
>>>> This communication may not represent my employer's views,
>>>> if any, on the matters discussed.
>>>>
>>>> On 13-Apr-13 18:25, Rob Jarratt wrote:
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Timothe Litt [mailto:litt at ieee.org]
>>>>>> Sent: 13 April 2013 22:40
>>>>>> To: r.jarratt at computer.org
>>>>>> Cc: Rob Jarratt; 'Johnny Eriksson'; simh at trailing-edge.com
>>>>>> Subject: Re: [Simh] DECnet for TOPS-10
>>>>>>
>>>>>> On 13-Apr-13 17:00, Rob Jarratt wrote:
>>>>>>> I wrote support for the KMC/DUP combo a long time ago, for simh
>>>>>>> v2.9.
>>>>>>>
>>>>>>> Works just fine, both for ANF and DECnet.  Sources are (still) at
>>>>>>> ftp://ftp.stacken.kth.se/pub/pdp10/v29upd if anyone is interested.
>>>>>>>
>>>>>>> I do not have any system up at the moment, due to a combination
>>>>>>> of HW
>>>>>>> problems and lack of time.
>>>>>>>
>>>>>>> --Johnny
>>>>>>>
>>>>>> If KDP (KMC/DUP) still works, it should be integrated into the PDP10
>>>>>> simulator.  TOPS-10 (ANF-10 and DECnet) supports the device, and
>>>>>> TOPS-20
>>>>>> (DECnet) supports it.  Both on the KS10.
>>>>>
>>>>> That sounds like we can get DECnet on TOPS-20 on SIMH, if so that
>>>>> would be
>>>>> really great!
>>>>>
>>>>>
>>>>>>> It went into the PDP10 emulation for a while but was later
>>>>>>> removed when we were informed that it would have represented an
>>>>>> impossible
>>>>>>> configuration as the DMC11 would have been in the PDP11 front end.
>>>>>> Whoever provided that information was correct for the DMC, but not
>>>>>> for
>>>>>> the DMR.
>>>>>>
>>>>>> For the KL, yes, the DECnet serial line adapters were in the PDP11
>>>>>> front
>>>>>> end.  Ethernet was on an internal channel.
>>>>>>
>>>>>> If the DMC can be configured as a DMR, it should go into the PDP10
>>>>>> simulator.
>>>>>
>>>>>
>>>>> Adding DMR support was on my list, but I haven't done it yet. I'll see
>>>>> if I
>>>>> can get the KMC/DUP code in and then do DMR, but it may be a while
>>>>> before I
>>>>> get time.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> As I said, I wrote a KS10 (Unibus) driver for the DMR on
>>>>>> TOPS10, which is in the distributed OS sources.  The DMC is
>>>>>> useless on
>>>>>> the KS10.  As I noted, the DMR uses fixed addresses in TOPS-10, not
>>>>>> the
>>>>>> usual Unibus floating addresses.
>>>>>>
>>>>>> Either device would allow TOPS-10 networking to work under simh.
>>>>>> TOPS-10
>>>>>> can be configured for either or both devices.  TOPS-10 DECnet will
>>>>>> work
>>>>>> as either a Phase III or Phase IV end-node on the KS10.  (I did the
>>>>>> Phase IV implementation for the KS.)
>>>>>
>>>>> Which phase(s) does TOPS-20 DECnet support on the KS?
>>>>>
>>>>>
>>>>>> I was a developer for TOPS-10, and supported TOPS-20 (among other
>>>>>> things), so this is authoritative.
>>>>>>
>>>>>> This communication may not represent my employer's views,
>>>>>> if any, on the matters discussed.
>>>>>>
>>>>
>>>>
>>>>
>>>>
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>>>> Simh at trailing-edge.com
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>>>>
>>>
>>>
>>
>>
>>
>>
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>
>


-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol