[HECnet] DECnet/Python

[Johnny Billquist]

On 2021-10-28 02:44, Peter Lothberg wrote:
> The MCB is a phase-3 node. I guess T20 used the same stuff as T10
> for the MCB, code is here:
> http://pdp-10.trailing-edge.com/decnet_mcb_cusps_703a/index.html
> 
> It's RSX "based" so maybe Johnny could make it Phase-4?

Anything is possible, but I suspect that could be quite some effort. :-)

   Johnny

> 
> On tops10 the problem with the MCB and DDCMP etc was solved with the
> "DDP" device that made a line (sync or async) on a ANF10 DN87*
> frontend a DDCPM device.
> 
> That way a Tops10 monitor that was phase-4 could speak sync/async
> to another phase-4 node.
> 
> I sent the tapes and disk packs with MRC's 4.x and 5.x tops20
> for 2020 to LCM.
> 
> The 4.x DECnet over DDCMP DUP/KMC for 2020 has reduced "segment size'
> from 576 to 390 or something like that due to limited buffer space.
> 
> 
> -p
> 
> 
> ----- Original Message -----
>> From: "tommytimesharing" <tommytimesharing at gmail.com>
>> To: "hecnet" <hecnet at Update.UU.SE>
>> Sent: Wednesday, October 27, 2021 8:29:35 PM
>> Subject: Re: [HECnet] DECnet/Python
> 
>> I had been wanting to put some DDCMP code back into later versions of
>> Tops-20.  I don't believe it exists in 5, 6 or 7.  I'm not sure if it
>> made it into MRC's version of 5 for the KS and those sources have yet to
>> be recovered.
>>
>> A KL class machine communicates with DECnet via the CI, the NI or a DTE,
>> which is a connection to a DN20.  A DN20 is a PDP-11 running DECnet (I
>> think it's MCB), but I believe you are limited to Phase III.  The last
>> time I was in that particular neck of the monitor woods, I believe I saw
>> that the Phase IV router code would not use a DN20 as a router.  I'm
>> pretty sure it would hand packets to to any node that the DN20 knew about.
>>
>> It didn't look like it would be a big deal to remove that restriction to
>> the DN20, but my recollection was that they never spoke full Phase IV.
>> So I would need something simulating a 'smart' DN20.  Maybe a brilliant
>> DN20.
>>
>> Or I could make the KMC/DUP look like a MASSBUS device, adapt the 4.2
>> UNIBUS based drivers to use that hardware paradigm and then simulate the
>> hardware and then graft the 4.2 DDCMP code to be another transport
>> option for the router.
>>
>> For some very strange reason, this is my idea of fun.

-- 
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