On Jan 29, 2022, at 7:37 PM, Johnny Billquist
<bqt(a)softjar.se> wrote:
On 2022-01-30 01:04, R. Voorhorst wrote:
L.S.
With a bit time on hand and the standstill after Paul's initial test from
dup to pydecnet which appeared to be successful, I now undertook a test as
Mark liked to have it preferably.
So I did a fresh netgen on a simple configuration from simple basic install
Rsx11MP system for only a Decnet end-node with one single Dup line
communicating to a known working Pdp11 Rsx11MP Dmc circuit.
I saw no difference from what I reported initially and later with logging,
as was to be expected; my complex setup behaves exactly the same in this
respect as it does for years in a complex network setup for Rsx and Rsts,
and RT11 without network.
This is on a Windows-2008R2 server and I suspect Paul did his test on
unix/linux , however although it differs, that should be moot as far as
Simh is concerned.
There could be another difference though. Paul would probably have taken the
default route and used Ddcmp withouth KG11 support: Dup without Kdp is the
only sync line to use it, though async Decnet DL/DZ/VH might use it as well.
As I prefer the most complex configs possible (any two of a kind where
possible as Dec used to have them), I do also employ the KG11, so for Dup
support it will be used when configured so in Decnet11MP.
I would suspect Paul did not run with KG11.
Correct, I was not aware it's possible to use it. The only software I have seen that
uses the KG11 is 2780 emulation.
I agree that the host system shouldn't make a
difference.
Not unless it's big endian, in which case getting this stuff to come out right
requires some care.
On a sim it is
not that effective, but in hardware in the past it did make a
difference for fast crc computing.
Actually, as the DECnet installation manual mentions, on an 11/44 or 11/70, you probably
do not want to use the KG11 even if you have it, as the software computation is faster
than the hardware device
(see page 5-31 of the DECnet-RSX generation and installation manual).
Makes sense. The KG11 is pretty old; if it was created back in the 11/20 days that would
make much more sense, with basic instruction times in the 3-5 microsecond range.
paul