Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!batcomputer!tedcrane
From: tedcrane@batcomputer.tn.cornell.edu (Ted Crane)
Newsgroups: comp.sys.dec
Subject: Re: How do I break out from a DEC DELNI to thin-wire Ethernet?
Message-ID: <8042@batcomputer.tn.cornell.edu>
Date: 25 May 89 02:50:43 GMT
References: <2988@crete.cs.glasgow.ac.uk>
Reply-To: tedcrane@tcgould.tn.cornell.edu (Ted Crane)
Organization: Tompkins County Computing, Ithaca, NY
Lines: 24

In article <2988@crete.cs.glasgow.ac.uk> shoat@cs.glasgow.ac.uk (Mr. David Shoat) writes:
>
>What's the best (only?) way to break out from a DEC DELNI onto thin-wire? 

I just had occasion, today, to try this, and it worked:
Connect a DESTA (< $300)) to the external Ethernet port on the DELNI.
If you don't know which one that is, it is the one to which the DESTA
fits without wierdness.  There's only one.
The slide switch has to be in the "external" position (open box as opposed
to closed box icon).

This connection is not documented anywhere that I found, and the local
DEC folk wouldn't say that it's supposed to work.  Common sense (along the
lines of "Ethernet is foolproof, and if the cables match physically, they
are meant to match electrically") says it should work ,and it does.

>Does anyone know why my whole damn network crashes every time I throw the
>switch on the DELNI which enables the external port?

If you have no transceiver or transceiver-substitute (as in the above
suggestion) connected to the port when its in external mode, you've got
the equivalent of a plumbing system with an end cap left off.  The bits
spill out.  Either disable the port (which still lets you chain DELNIs
together) or connect a transceiver to it.  Again, this should be intuitive!