[HECnet] Multinet alternatives ...

[Thomas DeBellis]

If they have any support at all, it will be with the KS processor (I.E., 
the 2020), which used the Unibus for I/O.  The other devices used 
Massbus, with two different I/O controllers (RH10/RH20).  I don't 
immediately recall KDP support in any of my sources, but I'm at 7 while 
the KS is at 4.2.

Otherwise, personally, I think it would be a cool idea for SIMH to have 
full support for DTE's and be able to boot MCB which would then handle 
DDCMP just fine.  Tops-20 still has code to handle messages coming from 
a DN20, however I seem to recall that it (the DN20) is limited to Phase 
III traffic whereas the PDP-10 will do Phase IV (via the NI).  Not sure 
what kind  routing for all this could be done.

At one point, Tops-20 DECnet appears to have had support for using X.25, 
but I don't know anything more about it.  We never used it.

On 2/26/20 10:36 AM, Mark Pizzolato wrote:
> On Tuesday, February 25, 2020 at 10:39 AM, Rob Jarratt wrote:
>> Mine won't talk to TOPS10/20, yet. I started something on that too if I remember
>> correctly, I did build a DDCMP implementation which I think partially worked.
>> I think I foundered on just getting DECnet running on TOPS20 on SIMH,
>> I did some work with Mark Pizzolato and Timothe Litt to build a KDP emulation,
>> but I struggled to keep up with them and gave up in the end. I am not sure where
>> that went.
> It was your initial work that inspired Tim's complete KDP work (OS DDCMP
> implementation) and the full fledged DDCMP in the DMC/DMR devices on the
> Unibus PDP and VAX simulators.  To the extent that either of these devices had
> OS support in TOPS10/20 they will work fine with whatever version of DECnet
> that used them.
>
> - Mark
>