Date   : Sat, 04 Jul 2009 20:42:24 +0100
From   : philb@... (Phil Blundell)
Subject: econet bridge protocol

Does anybody have documentation on the port &9c protocol used by
bridges?  Chapter 10 of the MDFS book gives some details but doesn't
describe the messages with control bytes &80 and &81.

Observing the single bridge that I have here, at power up it seems to
send a broadcast with control byte &80, containing in its payload the
number of its other local network; I guess this is the "reset packet"
that the MDFS book talks about.

If I send the bridge one of those packets (cb &80) then it responds with
a series of packets with control byte &81 and, again, the network number
of its far side in the payload.  I'm not entirely sure what the meaning
of these packets is, or how (if at all) I am meant to respond to them.

Can anybody shed any light on that?  Or, absent any documentation, is
there anybody with two or more bridges who would be prepared to capture
some packet dumps showing them talking to each other?

thanks

p.