Wanted: IBM PC compatible 8 or 16 bit Arcnet cards

Ethan Dicks ethan.dicks at gmail.com
Mon Dec 13 15:44:10 CST 2021

On Mon, Dec 13, 2021 at 3:09 PM Grant Taylor via cctalk
<cctalk at classiccmp.org> wrote:
> On 12/12/21 10:28 PM, Ethan Dicks via cctalk wrote:
> > I haven't used ARCnet since we used to use it for 4-player Doom
> > (especially since not everyone in the gaming group had Ethernet at
> > home yet and it was easy to make a passive 4-port ARCnet hub.
> I find this statement interesting for a couple of different reasons:
> 1)  Paying Doom over ARCnet.  --  I don't think I realized that ARCnet
> was standardized enough that normal networking applications would work
> over it.  --  Naivety on my part.

The Doom application contained a network stack that would handle the
higher layers.  IIRC, you still had to load a packet driver shim, but
perhaps not.  It's been a loooong time since I've done it.

But you definitely could play up to 4 players when each machine had an
ARCnet card.  Ethernet cards worked too but they cost a lot more at
the time.

> 2)  "it was easy to make a passive 4-port ARCnet hub" ... I don't know
> how to respond to that with anything but curiosity and /many/ open ended
> questions.


You just take 4 BNCs and 4 resistors.  Tie all the grounds together
(can use a metal bar or wire or whatever) and connect one resistor to
each core and tie all 4 resistors together.

In other words, ARCnet supports a Star topology that Ethernet does
not.  It's a token-passing scheme, not CSMA (collision detection).



> --
> Grant. . . .
> unix || die

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