[HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be Ddcmp --> MarkP

[Mark Pizzolato - Info Comm]

On Friday, November 19, 2021 at 12:33 PM, Reindert wrote:
> I updated the remark by Bob with this in my update and could not find that
> back in your copy of the mail transcript:
> 
> Before I get a storm this from Pdp11_dup.c should accompany it:
> 
>    The wire protocol implemented is native DDCMP WITHOUT the DDCMP
> SYNC
>    characters both initially and between DDCMP packets.

I still don't understand your problem.  The wire protocol is PACKETS, NOT bytes.  
The packets are transported over either UDP (as UDP packets) OR via TCP with 
a 2 byte packet header indicating the data length.  Any packet length is NOT 
presented across the simulator<->pdp11_dup device, just the data.  On transmit 
any interpacket bytes that are the DDCMP_SYNC character are stripped BEFORE 
the packet data is presented to UDP or TCP for outbound delivery.

- Mark

> -----Original Message-----
> From: owner-hecnet at Update.UU.SE [mailto:owner-
> hecnet at Update.UU.SE] On Behalf
> Of Mark Pizzolato - Info Comm
> Sent: Friday, 19 November, 2021 21:18
> To: R. Voorhorst <R.Voorhorst at swabhawat.com>; hecnet at Update.UU.SE
> Subject: RE: [HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be
> Ddcmp --> Re:4 --> Cryptic -->Dup11 simh only for Ddcmp --> update
> 
> 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