[HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be Ddcmp --> Re:4 --> Cryptic -->Dup11 simh only for Ddcmp --> update

[Mark Pizzolato - Info Comm]

On Friday, 19 November, 2021 at 20:42, Reindert wrote:
> Yes, that is how Pdp10 KS10 and Vax and Rsx and Rsts all interface to the
> Dmc/Dmr offered layer and for Anf10 on Pdp10 as well.
> But trying Decnet on bare Dup11 will reveal all.
> 
> However this will fail on simh: look at the comment in Pdp11_dup.c from
> Bob:
> 
>    dup          DUP11 Unibus/DPV11 Qbus bit synchronous interface
> 
>    This module implements a bit synchronous interface to support DDCMP.
> Other
>    synchronous protocols which may have been supported on the
> DUP11/DPV11
> bit
>    synchronous interface are explicitly not supported.
> 
> So the 0,01 % rises to 100% that it will not work as bare sync device

I don't see what you're saying will fail.  The comments very explicitly say 
that DDCMP will work.  Other possible uses of the DUP11/DPV11 will not 
work.  The reason they wouldn't work when this pdp11_dup.c was written
was due to the lack of software on the PDP11 side and something on the 
other end of a conversation to talk to.  If such a useful test case existed 
the functionality in the pdp11_dup.c code could be extended to support 
it.

- Mark


> -----Original Message-----
> From: owner-hecnet at Update.UU.SE [mailto:owner-
> hecnet at Update.UU.SE] On Behalf
> Of Paul Koning
> Sent: Friday, 19 November, 2021 17:23
> To: hecnet at update.uu.se
> Subject: Re: [HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be
> Ddcmp --> Re:4 --> Cryptic
> 
> I assume it means that RSX (and RSTS too) lets you use a DMC directly from
> an application as an I/O device you can open.  If so, you get a packet
> service that lets you transmit whatever packets you want, which will be sent
> encapsulated in DDCMP protocol.  In the RSX case I'd assume that includes
> support for maintenance mode (in RSTS that isn't supported).
> 
> 	paul
> 
> > On Nov 19, 2021, at 11:14 AM, R. Voorhorst
> <R.Voorhorst at swabhawat.com>
> wrote:
> >
> > Please can you explain your second sentence somewhat? I read:  "... the
> Ddcmp layer ... it does present it as a device ...". I do not perceive the
> connotation.
> >
> >
> > Reindert
> >
> > -----Original Message-----
> > From: owner-hecnet at Update.UU.SE [mailto:owner-
> hecnet at Update.UU.SE] On
> Behalf Of Johnny Billquist
> > Sent: Friday, 19 November, 2021 14:46
> > To: hecnet at Update.UU.SE
> > Subject: Re: [HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should
> be
> Ddcmp --> Re:4
> >
> > RSX definitely can use a DUP11 standalone through DECnet. In which case
> it's software side DDCMP.
> >
> > Heck, you can also use the DDCMP layer yourself, without involving
> DECnet.
> It does present it as a device to the system on which you can send/receive
> packets.
> >
> >   Johnny