Actually, switches (bridges -- same thing, just a different marketing
name) came way earlier. The first bridges showed up fairly soon after
Ethernet first shipped. I think the first one was the Vitalink bridge,
which would run over a satellite link (fairly slowly). The first
full-speed bridge was the DECbridge-100 (two AUI ports) -- it
established the performance standard for bridges, full speed wire rate
min size packets all the time. I don't remember when that product came
out -- perhaps 1984, maybe even a year or two earlier.
paul
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
Behalf Of jeep at scshome.net
Sent: Wednesday, October 28, 2009 11:57 AM
To: hecnet at Update.UU.SE
Subject: RE: [HECnet] DECrepeater 900TM
Like Paul said it is a hub not a switch. It was designed to be used
in
the DEChub-900 chassis or standalone. It just preceded the Alpha
family of systems so was targeted at VAXen (10base-T) based systems.
Switches came afterwards.
-Steve
_____
From: owner-hecnet at Update.UU.SE on behalf of Paul Koning
Sent: Wed 10/28/2009 11:31
To: hecnet at Update.UU.SE
Subject: RE: [HECnet] DECrepeater 900TM
I found a manual online:
http://www.carnagevisors.net/dec94mds/detmminb.pdf
It's a repeater (a.k.a., hub) not a switch (a.k.a., bridge). It's not
fancy at all. A repeater takes incoming Ethernet transmissions and
repeats them on all the other ports unconditionally. Also, a repeater
is by definition a half duplex device, so you have the CSMA/CD
(collisions and all that) of classic Ethernet. A bridge receives a
packet and transmits it on the appropriate output port (if any), and
can
be full duplex.
The 900TM is 10Base-T, so 10 Mb/s Ethernet -- not fast Ethernet
(100Base-T). Suitable for old slow Ethernet devices...
paul
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE]
On
Behalf Of Mark Wickens
Sent: Wednesday, October 28, 2009 11:22 AM
To: hecnet at Update.UU.SE
Subject: [HECnet] DECrepeater 900TM
Can someone explain to me what a decrepeater 900tm is? Is is a fancy
32
port 10MB switch?
Regards, Mark.
--
Like Paul said it is a hub not a switch. It was designed to be used in the DEChub-900 chassis or standalone. It just preceded the Alpha family of systems so was targeted at VAXen (10base-T) based systems. Switches came afterwards.
-Steve
________________________________
From: owner-hecnet at Update.UU.SE on behalf of Paul Koning
Sent: Wed 10/28/2009 11:31
To: hecnet at Update.UU.SE
Subject: RE: [HECnet] DECrepeater 900TM
I found a manual online:
http://www.carnagevisors.net/dec94mds/detmminb.pdf
It's a repeater (a.k.a., hub) not a switch (a.k.a., bridge). It's not
fancy at all. A repeater takes incoming Ethernet transmissions and
repeats them on all the other ports unconditionally. Also, a repeater
is by definition a half duplex device, so you have the CSMA/CD
(collisions and all that) of classic Ethernet. A bridge receives a
packet and transmits it on the appropriate output port (if any), and can
be full duplex.
The 900TM is 10Base-T, so 10 Mb/s Ethernet -- not fast Ethernet
(100Base-T). Suitable for old slow Ethernet devices...
paul
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
Behalf Of Mark Wickens
Sent: Wednesday, October 28, 2009 11:22 AM
To: hecnet at Update.UU.SE
Subject: [HECnet] DECrepeater 900TM
Can someone explain to me what a decrepeater 900tm is? Is is a fancy
32
port 10MB switch?
Regards, Mark.
--
I found a manual online:
http://www.carnagevisors.net/dec94mds/detmminb.pdf
It's a repeater (a.k.a., hub) not a switch (a.k.a., bridge). It's not
fancy at all. A repeater takes incoming Ethernet transmissions and
repeats them on all the other ports unconditionally. Also, a repeater
is by definition a half duplex device, so you have the CSMA/CD
(collisions and all that) of classic Ethernet. A bridge receives a
packet and transmits it on the appropriate output port (if any), and can
be full duplex.
The 900TM is 10Base-T, so 10 Mb/s Ethernet -- not fast Ethernet
(100Base-T). Suitable for old slow Ethernet devices...
paul
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
Behalf Of Mark Wickens
Sent: Wednesday, October 28, 2009 11:22 AM
To: hecnet at Update.UU.SE
Subject: [HECnet] DECrepeater 900TM
Can someone explain to me what a decrepeater 900tm is? Is is a fancy
32
port 10MB switch?
Regards, Mark.
--
At 4:08 AM +0100 10/28/09, Johnny Billquist wrote:
Guilty, PONDUS is usually the machine that reacts most quickly to
DECserver boot requests...
In that case I need to figure out where I stuffed my DS200. :-) Sounds like it is time for me to finally think about figuring out if it works.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
A typical crimper has a cavity that holds the connector, using the
locking tab to lock it into position. So an MMJ crimp requires an MMJ
cavity, and a standard RJ11 one is unlikely to work. (I assume you
meant RJ11 -- RJ12 is the telephone handset connector, which is
narrower.)
Cheap crimpers have the cavity as part of the tool; more expensive ones
have interchangeable "dies" and for those an MMJ die may well be
available. I'd expect the ones from the likes of AMP, for example, to
offer that, though finding the MMJ die nowadays is likely to be fairly
hard...
paul
-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
Behalf Of Mark Wickens
Sent: Wednesday, October 28, 2009 10:08 AM
To: hecnet at Update.UU.SE
Subject: [HECnet] Crimper
Best bet I would have thought was ebay - that's where I picked mine up
from - it's second hand and specifically for MMJ. Not sure whether a
generic RJ12 crimper may do the job, would depend on how it handled
the
tab. I've thought about doing a bulk order of MMJ connectors - if
there
is some interest out there for taking some off my hands I'd consider
it.
Regards, Mark.
--
Mark Wickens wrote:
On Wed, 2009-10-28 at 10:15 -0400, Fred wrote:
On Wed, 28 Oct 2009, Johnny Billquist wrote:
I have someone booting some DECserver 200 which was served by PONDUS:: (It's all in the logs...)
Only a couple of days ago.
For some reason that strikes me as "pretty neat". It all goes over the bridge and onto HECNet "somewhere" to find a host willing to do a load. :)
Fred
That's exactly what I was thinking... might save me having to dig out my
decserver software firmware sometime...
PONDUS can serve the firmware for DECserver 100, DECserver 200 and DECserver 300. That's all the firmware I have, and I also suspect that I cannot get RSX to feed MOP images for other models, because RSX wants to be picky about some stuff I think it should properly ignore.
Johnny
Johnny Billquist wrote:
Mark Wickens wrote:
Best bet I would have thought was ebay - that's where I picked mine up
from - it's second hand and specifically for MMJ. Not sure whether a
generic RJ12 crimper may do the job, would depend on how it handled the
tab. I've thought about doing a bulk order of MMJ connectors - if there
is some interest out there for taking some off my hands I'd consider it.
Regards, Mark.
I think there are/were crimpers that did manage both. Specifically designed for that.
I still have a small stash of MMJ connectors, but I could buy of bunch, if you ordered.
cables.com has them for US$0.19 apiece. I buy them in lots of 100.
Peace... Sridhar
Fred wrote:
On Wed, 28 Oct 2009, Johnny Billquist wrote:
I have someone booting some DECserver 200 which was served by PONDUS:: (It's all in the logs...)
Only a couple of days ago.
For some reason that strikes me as "pretty neat". It all goes over the bridge and onto HECNet "somewhere" to find a host willing to do a load. :)
Indeed. However, it might be worth pointing out that doing MOP boots, as well as LAT in general, will only work over my bridge software, and not over DECnet-over-Multinet.
LAT and MOP are not properly a part of DECnet. However, my bridge program can bridge those protocols as well (optional, you can enable only DECnet, or LAT/MOP if you want to).
Johnny
Brian Hechinger wrote:
I have made my own cables in the past, although I've now run out of MMJ
connectors. I have a whole reel of cable if anyone needs some, or if you
have some MMJ connectors and need cables I can make them up for you.
I really need to get myself a crimper that does MMJ. Any recommendations?
I'd like one that does both MMJ and RJ45 if possible.
Ideal Crimpmaster. Takes interchangeable dies. MMJ is available. Don't get an imitation one.
Peace... Sridhar
