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:[email protected]]
Sent: 13 April 2013 22:40
To: [email protected]
Cc: Rob Jarratt; 'Johnny Eriksson'; [email protected]
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.
_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh
_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: [email protected] || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh
