22 Sep
2008
22 Sep
'08
2:18 a.m.
Ethan Dicks wrote:
this happened. IIRC, it was determined that the DEQNA
couldn't
juggle a received packet while a new one was coming in. I can't
confirm that it's a single-buffered issue, but it sounds like it
fits the symptoms.
I think the DEQNA was DEC's first Qbus ethernet card. It certainly had
some "issues" and I think that was a known one. I don't think it could
be fixed, although I recall some version of VAX/VMS had a work around of
sorts that allowed recovery (some SYSGEN parameter could be set to
enable this recovery). The DEQNA was the first ethernet adapter for
which
VMS dropped support. I think this happened when the FFS driver interface
came along. I presume that DELQA and DELQA-YM fixed all this up - I
don't recall any complaints about those.
Exactly. The same was true for small VAXen, from what
I saw.
I wasn't sure what that meant in context.
If it meant that small VAXen (of the time) couldn't generate enough
traffic
to flood an ethernet, I think that's true. The DTJ article about the
DEMNA
(or the XMI ethernet interface, in case I've misrememberd the name!)
said
somewhere in it that it was the first DEC ethernet adapter that could
sustain
maximum ethernet xfer rate.
If it meant that other small VAXen could not cope with back to back
packets,
then I doubt that that is true. DEC did usually try to improve things as
time
went by :-)
Antonio