[HECnet] LQA system ID message

[Johnny Billquist]

On 2013-02-16 23:12, John Wilson wrote:
From: <Paul_Koning at Dell.com>

Well, I did now, and simh is right. Page 3-31 of the DELQA manual states
that the first address is used as the source address for system ID messages.

Which edition?   I'm looking at EK-DELQA-UG-002 (from Bitsavers) and it can't
find anything like that.

I have the same edition (hardcopy) and I think the final paragraph on 3-31
is just being read wrong.   They talk about the "first" physical address, but
it seems like what they mean is the first address that's a physical address,
not any address of any kind that's in the first slot of the SETUP packet.

I take that to mean (and this is what E11 does) the LQA doesn't work the
same way as the QNA, so while the QNA hardware may blindly accept anything
that matches any slot in the SETUP packet, the LQA searches that list for
the first non-broadcast/non-multicast address and takes that to be the One
True Address, and that's what goes in system ID frames and gets set in the
Ethernet chip as the station address for reception.   That certainly seems
like the cleanest interpretation, and DEC was pretty good about picking
the clean choice over the quick-and-dirty one.

I'm kind of swamped but if anyone's really lying awake nights worrying about
this, I do have a real DELQA and a BA23 here that I guess I could set up
with a bus adapter for testing (either under RSTS or I could hack up my XH:
test code to try different stuff in SETUP packets).   Lemme know.

You are probably right, John, in which case simh does it wrong.

Reading through the whole section over and over, it do feel more like it would scan through the list and grab the first non-broadcast address (no matter which column it is in), and use that one.

	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