[HECnet] TOPS-10 KS10 Ethernet Monitor

[Johnny Billquist]

On 2015-04-26 21:34, Dave McGuire wrote:
> On 04/26/2015 03:30 PM, Mark Pizzolato - Info Comm wrote:
>>>> I've been attempting to (likely incorrectly) get the DEUNA emulation
>>>> working in SIMH's KS10 simulator.
>>>>
>>>> Current status:
>>>> * Exists
>>>> * Has an address
>>>> * Has a vector
>>>> * Can be enabled
>>>> * Can attach to host interface
>>>>
>>>> ...and that's as far as I've gotten.  Currently having issues getting
>>>> TOPS-10 to successfully link for KS10 with ethernet support.  Anyone
>>>> have a pre-genned MONITOR executable?
>>>
>>> I barely know C...but my patches work:
>>>
>>> .r [1,2]arplst
>>>
>>> 10.10.0.9 is at d0:63:b4:00:6e:53, ttl = 300
>>> 10.10.10.2 is at 20:c9:d0:da:8f:67, ttl = 300
>>> 10.10.2.3 is at 08:00:27:6b:99:01, ttl = 300
>>> 10.10.10.1 is at 68:05:ca:2b:6e:be, ttl = 300
>>> 10.10.10.16 is at 00:14:69:e2:75:57, ttl = 300
>>> 10.10.1.3 is at 08:00:27:ca:5a:c2, ttl = 300
>>>
>>> 10.10.2.3) at 08:00:27:6b:99:01 on em0 expires in 1068 seconds [ethernet]
>>> (10.10.1.3) at 08:00:27:ca:5a:c2 on em0 expires in 1179 seconds [ethernet]
>>> (10.10.10.1) at 68:05:ca:2b:6e:be on em0 permanent [ethernet]
>>> (10.10.10.16) at 00:14:69:e2:75:57 on em0 expires in 1063 seconds [ethernet]
>>
>> I have very little experience with TOPS-10, and that is only as a user...
>>
>> Meanwhile, we removed the DEUNA from the simh PDP10 (KS10) simulator since, according to Timothe Litt, besides his unfinished midnight project, there was never DECnet code delivered on the KS10 which could use it.
>>
>> The arplst output suggests you're working with an IP stack here.
>>
>> Where does the code for this IP stack come from, and what context was it used under?
>>
>> If useful code exists, I'll be glad to put the DEUNA device back into the simh PDP10 simulator.
>
>    It seems to me that, if one can plug a particular board into a slot in
> a particular machine, one should be able to do the same with simh,
> regardless of what *old* code may or may not support it.  People are
> writing new stuff for these machines all the time; witness BQT's IP
> stack for RSX for example.
>
>    I myself have multiple KS10 systems here, and would love to be able to
> plug DEUNAs into their Unibus chassis at some point and have it actually
> work.  DEUNA support in simh would surely be instrumental in allowing
> that to happen.

All true and good points.
I'm curious on exactly how a DEUNA/DELUA works in a KS-10. Does anyone 
know? Does it do 8-bit-byte DMA to the 18-bit memory, leaving the top 
two bits alone. Or does it only work if it do word DMA (would be 
strange, as the controller itself can send and receive odd byte length 
ethernet packets).

And how does the whole controller actually work in a KS, since the 
controller expects there to be control structures in memory, which are 
used to manage the buffers. Those are expected to be 16-bit fields at 
one address, and an additional 2 bits of address in another word.

Is there some potential problem with regards to a PDP-11, which have two 
parity bits for data, which are used for actual data on a KS? (If I 
remember right.)

In short, this is not trivial, and if it works on a real machine, the 
emulation needs to reflect that truthfully, or else it will not be so 
useful. I suspect it should work on a real machine, as hints suggested 
that it was at least considered.

	Johnny

-- 
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