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From: Wilko Bulte <wilko@yedi.iaf.nl>
Message-Id: <199710021854.TAA00977@yedi.iaf.nl>
Subject: Re: thickwisre<->thinwire
To: totii@est.is (=?iso-8859-1?Q?=DEor=F0ur?= Ivarsson)
Date: Thu, 2 Oct 1997 19:54:02 +0100 (MET)
Cc: chuckr@Glue.umd.edu, FreeBSD-Hackers@FreeBSD.ORG
In-Reply-To: <3433C896.41C67EA6@est.is> from "=?iso-8859-1?Q?=DEor=F0ur?= Ivarsson" at Oct 2, 97 04:19:40 pm
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As =?iso-8859-1?Q?=DEor=F0ur?= Ivarsson wrote...
> Wilko Bulte wrote:
> > 
> > As Chuck Robey wrote...
> > > I'm doing a bit of computer re-arrangement (keeps my life interesting) and
> > > I find I have to connect another computer to my existing home ethernet.
> > > Trouble is, the ethernet is thinwire, and the new computer (a DECStation
> > > 5000/120, which will be running NetBSD) is thickwire.  I'm going to be
> > > connecting it to my two existing FreeBSD boxes.
> > 
> > It probably has an AUI 15 pin D connector. Just find a thinwire tranceiver,
> > they are quite abundant. Or if you have an AUI-10base5 tranceiver, rewire
> > it to use a BNC connector. The electronics are the same for 10base2 and
> > 10base5 (at least they are not distinguishable in normal use)
> > 
> The specs changes only little and does not care for short cables.
> The main difference is the velocity factor of Thick Wire is lot higer
> than
> Thin Wire cable. The electronic is the same.

Not completely. The collision detect uses a diode connection to the central
conductor on the thinwire tranceiver, and is directly connected for
thickwire (or the other way around, I forgot that detail). This is at least
the difference in the NS8392 based implementation I used when I built
a couple of tranceivers myself (years ago, when they were rare and $ were
few ;-)

Wilko
_     ____________________________________________________________________
 |   / o / /  _  Bulte  email: wilko@yedi.iaf.nl http://www.tcja.nl/~wilko
 |/|/ / / /( (_) Arnhem, The Netherlands - Do, or do not. There is no 'try'
----------------------------------------------------------------------Yoda