[Simh] Anyone Have a SIMH Disk Image of a Phase III Node That Uses KDP or DUP?

Fri Aug 2 13:08:50 EDT 2013

TOPS-20 for the KS is Phase II. Really.  Besides having a pretty good 
memory, I have recently re-read the sources and have decoded the node 
initialization messages actually sent while working on the KDP.

PMR is fine for getting from a Phase II node out past a Phase III.  And 
yes, Phase II did support star topologies with so-called "intercept 
nodes" as routers (well, link forwarders.)  Phase II messages have an 
optional routing header to support this.

The KL did Phase III via the MCB (pdp-11 front ends), and eventually 
Phase IV over the KLNIA (ethernet).  The phase III implementation 
actually had the MCB masquerade as the -20 (Phase III), while talking 
Phase II to the -20.  Ugly, but at the time, the quickest way to get to 
Phase III.  Phase IV is when the -20 itself actually became smart.

The TOPS-20 group abandoned the KS at Phase II, arguing that the KS 
couldn't support the newer, larger monitors.  Marc Crispin managed to 
squeeze much of the newer code into a KS, but it was very low on address 
space and never released.

I did not want TOPS-10 to fork, so I made TOPS-10 on the KS run DECnet 
Phase IV. TOPS-10 kept the KS going thru the end.  (Well, thru the present.)

Since I'm probably what's left of DEC in 36-bit land, I'm not too 
worried about 'official support' :-)

Yes, Phase III is a solid product, as is Phase IV.  (But Phase V is an 
engineering marvel - that broke all the rules for a sensible user 
interface: complexity, compatibility.  It's so unpopular that HP still 
offers Phase IV as an alternative on VMS today!  It's a shame that it 
turned out that way.)

We'll see how far we can get with a VMS 3.something node - Rob thinks he 
can scare up a kit.

This communication may not represent my employer's views,
if any, on the matters discussed.

On 02-Aug-13 12:24, Johnny Billquist wrote:
> On 2013-08-02 13:02, Timothe Litt wrote:
>> DEC shipped a product kit for DECnet that was simply a patch to enable
>> it.  It's kicking around the net.
>
> Are you talking about for VMS now, or something else...?
>
>> Phase III is useful because Phase II nodes (and TOPS-20 on the KS is
>> one) can talk to it.  DECnet provided compatibility, but only between
>> adjacent Phases...
>
> I'm not aware of anything talking much of phase II. I'm pretty sure 
> T20 on a KS talks phase III, but I could be wrong. The documentation 
> is out there, so it should be easy to verify.
>
> I know that DECnet-8 was only phase II, but I think everything else 
> went beyond that.
>
>> So with a Phase III node, one can have T20 -> PIII -> PIV -> PV ->
>> anything.
>
> Sortof. Phase II nodes do not even understand routing, and expect all 
> the nodes it want to talk to to be adjacent, not to mention the very 
> limited number of nodes supported by phase II, and other oddities. (I 
> think a topology like a star was supported, but I can't remember the 
> details...) Also, it is still not supported to have a phase II node to 
> to a phase IV node, even through an intermediate phase III node, if 
> you want to talk about what DEC officially supported.
>
>> But even just Phase III gets around the 2-sync line limitation of the 
>> -20.
>
> Right. Phase III is when things became sortof sane, even if there are 
> still various limitations around.
>
>> Either VMS or RSX would work for Rob's purposes.  (I have the same
>> requirement, but haven't tracked down an old VMS kit. )
>>
>> So would TOPS-10 V7.02 - which I should have, but it's not on a disk
>> I've restored as yet.  Too many projects, not enough hours.
>
> :-)
>
> Time. Always a problem.
>
>     Johnny
>
>>
>> This communication may not represent my employer's views,
>> if any, on the matters discussed.
>>
>> On 02-Aug-13 06:28, Johnny Billquist wrote:
>>> On 2013-08-02 06:14, Cory Smelosky wrote:
>>>>
>>>> On Fri, 2 Aug 2013, Jarratt RMA wrote:
>>>>
>>>>> I would like to get hold of a SIMH image of a Phase III DECnet node
>>>>> that
>>>>> wants to speak over a simulated KDP or DUP, both of which are 
>>>>> currently
>>>>> being added to SIMH.
>>>>>
>>>>> I believe my best chance might be an RSX system, I have generated an
>>>>> RSX
>>>>> system once before but struggled a bit, so if anyone has something
>>>>> ready
>>>>> made it would be a big help.
>>>>>
>>>>> Thanks
>>>>>
>>>>> Rob
>>>>>
>>>>
>>>> If you have the license kit for 3.x, I could get Phase III going on 
>>>> VMS
>>>> pretty quickly.
>>>
>>> Wouldn't phase III imply a system way before anything like a license
>>> manager facility existed?
>>>
>>> As for RSX, I doubt people in general would have kept such systems
>>> around just for the fun of it. Phase III is pretty old and long ago.
>>>
>>>     Johnny
>>>
>>> _______________________________________________
>>> Simh mailing list
>>> Simh at trailing-edge.com
>>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>>
>>
>
>

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