Classic Computer Auctions List

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Wed Jan 27 07:25:09 1999

> > And you'll end up with a ring architecture, since if I remember correctly,
> > each drive only had two IO ports on it. That is, if you don't hack some
> > hardware to get a parallel connection to each computer (like 10BaseT hubs
> > today). And you'll need to select your problem domain to complement the
> > speed issues you'll have in communication, or you may end up with something
> > that's slower than a single C-64.

Other topologies are possible including serial bus and star with trivial
to none in the way of hardware to do it.

The easiest using a few disods and resistor is a serial bus that runs
CSMA/CD. If that sounds familiar lookup IEEE802.5...

Anyhow I"ve done this before and the trick is to make the transmitter look
like an open collector (takes one diode) so that RXand TX for every node
can be on the bus (coax or twisted pair with pull up or down resistor).
Collision detection and carrier sense are via spare port bit (or CTS RTS
lines). I've run such a bus at speeds up to 115kb/S and even 9600baud
it's very useful.

Allison
Received on Wed Jan 27 1999 - 07:25:09 GMT