DEC AUI Cable

From: Tothwolf <tothwolf_at_concentric.net>
Date: Wed Mar 19 15:03:00 2003

On Wed, 19 Mar 2003, chris wrote:

> What is DEC AUI Cable? ie: What is it used for, and what kind of wire is
> inside?
>
> I have 3 lengths of the stuff, and its stiff as hell. Feels like maybe
> multiple strands of co-ax or something. The jacket is labeled 4PR so
> that might make sense. It has 15 pin D-shell right angle connectors on
> it.
>
> I'm just curious about it.

It's used to connect an AUI transceiver to an AUI network interface. Ages
ago (well, has it really been *that* long ago?), you'd have a run of RG11
coax that you would literally drill into and attach a tap to. You would
then attach the ethernet transceiver to the tap, which would be cabled to
the computer's network interface with an AUI cable. Later on, as RG11
backbones were replaced UTP, fiber, and even RG58 in some cases, other
transceivers were produced, and conversion kits were also available for
the older tap-type transceivers so they could use a BNC connector.

The cable contains, if memory serves, 4 twisted pairs each with a foil
wrap shield, possibly a 5th unshielded pair for 12VDC (can't remember for
sure, maybe one of the 4 pairs is normally used for this), and everything
is then covered with a mylar plastic wrap, a foil shield, and then a
braided shield. To top it off, many cables use a Teflon jacket, which
makes them suitable for use in air plenums (suspended ceilings). PVC
jacketed cables are not suitable for plenum use, since PVC will release a
toxic gas if heated above a certain temperature, as would happen in a
fire.

(Yep, I'm back. My ISP had major issues for ~2 months, and I finally got
someone to take notice and do something about them. Now I have a 2500-3000
classiccmp message backlog to read over...)

-Toth
Received on Wed Mar 19 2003 - 15:03:00 GMT