[HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be Ddcmp --Re2

[Johnny Billquist]

Fair enough.

But DUP11 is a sync character based interface. So that one too requires 
that you do DDCMP in software. But I didn't think simh simulated a DUP11?

   Johnny

On 2021-11-18 23:33, R. Voorhorst wrote:
> Yes, but they are async lines and these are indeed character based with software determining the protocol, not so the sync liness. Async decnet ddcmp behaves slightly differently from sync decnet ddcmp in number of characters used. Look at the packet contents in used characters and in between.
> 
> Reindert
> 
> -----Original Message-----
> From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On Behalf Of Johnny Billquist
> Sent: Thursday, 18 November, 2021 23:23
> To: hecnet at Update.UU.SE
> Subject: Re: [HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should be Ddcmp --Re
> 
> Well... RSX for example can talk DDCMP over DZ11 or DL11 lines just as well, which are plain simple serial lines existing in simh.
> Hopefully such lines can be connected with interfaces doing DDCMP in hardware (simulated in simh of course), and it should all work.
> 
> And any software running in RSX just have an interface that gives the DDCMP packet layer. The actual serial lines are not accessible as such by any other software than the DDCMP driver.
> 
>     Johnny
> 
> On 2021-11-18 23:01, R. Voorhorst wrote:
>> Point in this case is that the ddcmp is handled in Simh and not in system software so software can only deal with packets/messages; there is need for a simh sync line where the software itself will be able to communicate in bytes/characters and synthesize the packets/messages as the next higher organization.
>>
>> Reindert
>>
>> -----Original Message-----
>> From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
>> Behalf Of Johnny Billquist
>> Sent: Thursday, 18 November, 2021 22:39
>> To: hecnet at Update.UU.SE
>> Subject: Re: [HECnet] ANF10 network --> DN200 (RJE, Decnet) --> should
>> be Ddcmp
>>
>> Well, a serial line over which DDCMP is running is purely a packet based interface.
>>
>>      Johnny
>>
>> On 2021-11-18 21:46, R. Voorhorst wrote:
>>> Indeed it is Ddcmp, but the meaning is the difference between
>>> packet/message oriented and character oriented and the latter should also exist.
>>>
>>> Reindert
>>>
>>> -----Original Message-----
>>> From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
>>> Behalf Of Robert Armstrong
>>> Sent: Thursday, 18 November, 2021 21:11
>>> To: hecnet at Update.UU.SE
>>> Subject: RE: [HECnet] ANF10 network --> DN200 (RJE, Decnet)
>>>
>>>> Paul Koning <paulkoning at comcast.net> wrote:
>>>> They speak DDCMP, yes, but not DECnet.  Any protocol layered over
>>>> DDCMP
>>> should work.
>>>
>>>      Indeed, and we just proved that with ANF10 which uses the DMCs
>>> and DUPs but is not DECnet.
>>>
>>> Bob
>>>
>>>
>>>
>>
> 

-- 
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