19 Mar
2005
19 Mar
'05
3 p.m.
On Mar 19 2005, 21:32, Jules Richardson wrote:
The Ethernet card may be a source of trouble. It seems
to want
something
that provides an external heartbeat - we hooked up a
DEC hub to get
around that problem, which stopped the "no carrier" messages on the
console. However, it's still throwing up "Ethernet jammed" messages -
and ideas what that's about?
Have you got the "SQE Test" turned on on your transceiver? You have to
turn it off if you have the transceiver connected to a repeater (which
is probably what your DEC hub is). What the SQE test does is send a
test signal after every frame, to test the collision detect circuitry,
but the repeater will see this as a real collision and will send a jam
signal.
--
Pete Peter Turnbull
Network Manager
University of York
19 Mar
19 Mar
3:43 p.m.
On Sat, 2005-03-19 at 23:00 +0000, Pete Turnbull wrote:
On Mar 19 2005, 21:32, Jules Richardson wrote:
We couldn't get it to work with any transceiver we tried (SQE test was
off, FWIW), whether hooked up to a hub or not - it still gave a
complaint about heartbeat at startup and then subsequent "no carrier"
errors (and the "Ethernet jammed" errors).
However, with one of these DEC "hubs", connected via 15-pin AUI cable,
it was happier - at least the hearbeat / no carrier errors went away -
but we were still getting the "Ethernet jammed" messages.
As said in a private mail just now though, we'd had this problem with
our PDP 11/84 - on the advice of an ex-DEC chap, it'd only talk to one
of these DEC units rather than any kind of AUI-equipped hub (or a
transceiver). On a whim we tried the same with the Sun, and it seems to
have improved matters.
But maybe "Ethernet jammed" is just Sun's way of saying that it's
trying
to communicate with the outside world and nothing anywhere is reachable
- in other words it's just a software thing rather than it indicating
any kind of hardware prob.
Personally I'm just amazed how little work the machine needed :) Apart
The Ethernet card may be a source of trouble. It
seems to want
something
that provides an external heartbeat - we hooked
up a DEC hub to get
around that problem, which stopped the "no carrier" messages on the
console. However, it's still throwing up "Ethernet jammed" messages -
and ideas what that's about?
Have you got the "SQE Test" turned on on your transceiver? You have to
turn it off if you have the transceiver connected to a repeater (which
is probably what your DEC hub is). What the SQE test does is send a
test signal after every frame, to test the collision detect circuitry,
but the repeater will see this as a real collision and will send a jam
signal. from four capacitor smoking events and one explosion it
all went really
well - I'm particularly amazed that the hard disk was still
operational.
It seems it was last powered up in 1991. Hats off to Sun for allowing a
terminal to be used as input whilst output still goes to the framebuffer
- I don't think modern Suns do that (it's keyboard/framebuffer or
terminal, no mix 'n match)
cheers
Jules
7219
days inactive
7219
days old
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julesrichardsonuk＠yahoo.co.uk -
pete＠dunnington.u-net.com