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.
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.
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 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.
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.TOPS-20 can participate in a modern network.More or less. There are some restrictions.
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. JohnnyAdding 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. --JohnnyIf KDP (KMC/DUP) still works, it should be integrated into the PDP10simulator. 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 animpossibleconfiguration 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 frontend. 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 onTOPS10, which is in the distributed OS sources. The DMC is useless onthe KS10. As I noted, the DMR uses fixed addresses in TOPS-10, not theusual 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 workas 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
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