ArcNet and the Pursuit of Multiple Topologies

From: Iggy Drougge <>
Date: Tue Oct 9 17:55:58 2001

Tarsi skrev:

>I've decided that one of my goals is to run every networking topology
>possible in my house, regardless if I actually NEED to run them or not. :)

A very admirable decision.

>My plan is to place 1 linux box running a card from each topology in it and
>use that to bridge all (or almost all) topologies.

>I currently have running 10bT ethernet, 10b2 ethernet, Localtalk over
>PhoneNET and the beginnings of Arcnet.

>In light of such, I have a series of questions:

>1) Who knows some stuff about ArcNet? I've gotten 4 cards (8-bit ISA) and a
>16-port active hub. I've read somewhere that cards are either hubbable or
>not. Any other info on that?

It depends on the "hybrid" chip on the card.
I'll just cut this from the Amiga 4000 hardware guide:
The A2060 has some bugs. First, the "hybrid" chip that forms the electronic
interface to the Arcnet network comes in two different versions: HCY 9058 (for
bus networks) and HCY 9068 (for star networks). As the A2060 manual describes
it, the board is for a bus network, but many A2060s come with the 9068 (star)
hybrid installed. A bus network needs 93-ohm terminators at each end, and this
works fine with the 9058 (bus) version of the hybrid. With the 9068, however,
the hybrid itself performs the termination. To connect two machines with 9068
hybrids, run coax from one machine to the other, without using terminators.
Using T-connectors to attach more machines in the middle of the bus may or may
not work, due to each one adding its termination to the bus. To connect a
9068-version A2060 to a bus network of 9058-version A2060s, place it at the
end of the chain and connect the cable directly, without a terminator (this
may limit the network to only being operational when the 9068-equipped machine
is on). Both versions of the card should have no problems when attached
directly to an active hub. It is also possible to replace the HCY 9068 hybrid
with the 9058 version, provided you can locate one.

There are both active hubs, of which you've apparently got one, and passive
hubs, which are just little boxes with a few (four on mine) BNCs on.

BTW, I've got a funny ISA ethernet card which may be jumpered between several
different impedance levels, so tha tit may be run off ARCnet cabling as well
as ethernet and even video cabling, IIRC.

>2) Anyone have any (I think it is) 93ohm coax arcnet patch cables that they
>want to get rid of?

Unfortunately none that I'd like to get rid of. But it shouldn't be impossible
to buy cable at an electronics shop and crimp/solder yourself.

>4) Any other interesting topologies I should try? I have plans to do:
>Arcnet, FDDI, Token ring, Localtalk, 10b2, 10b5, 10bT, 10bTX, 10bFiber, and
>(eventually) 802.11b wireless.

Well, one person in SUGA has a thing called Amigalink, which is some really
queer token-passing ring network. It uses D9 connectors at the back on the
card, with cables going between D9 and a multi-segmented socket much like 6,3
mm earphone sockets. Those sockets plug into a box which in turn is part of
the ring.
The official name of the network was the "Superlink unidirectional buffer
insertion ring netwrk", and there were adapters for CP/M, MSDOS and Amstrads,
too. But this thing is really, really obscure.

But I think you should run a piece of ECONET. I think that there is some
inital support in NetBSD now thanks to the arm26 portsmaster, Ben Harris(?).

En ligne avec Thor 2.6a.
Vi m?ste vara r?dda om varandra
                              - det ?r det enda reciproka pronomen vi har.
Received on Tue Oct 09 2001 - 17:55:58 BST

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