*BSD News Article 30221


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Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!bunyip.cc.uq.oz.au!un!pc012
From: pc012@un.seqeb.gov.au (Patrick Collins)
Subject: RTS/CTS half duplex system
Message-ID: <CpMM3o.Is4@un.seqeb.gov.au>
Organization: SEQEB
X-Newsreader: TIN [version 1.2 PL2]
Date: Wed, 11 May 1994 06:59:47 GMT
Lines: 31

I want to set up a slip link between a few FreeBSD systems using a 
Motorola Darcom digital point to multipoint radio system. Basically the 
radio system works as follows.

(1)	When a node wants to transmit it waits for the channel to be free 
by monitoring CD, when CD is inactive the channel is free. The RTS line 
is then asserted and we wait for approx 20 mS for the CTS line to become 
active. The 20 mS allows the transmitter and any repeaters to settle.

(2)	When CTS has become active I can commence my transmission which 
will be received by every other node on the system. Every other node will 
also see there CD signal become active indicating that the channel is in 
use (meaning that valid data is available and that they should not 
transmit just now).

(3)	When I have finished my transmission I de-assert RTS and the 
channel is now free for other nodes.

(4)	This system works at a 9600 bps.

(5)	No error correction is provided by the radio system.

(6)	Basically it should operate just like a slip link but some code 
will have to be hacked in order to control the RTS, CTS and CD lines.

My question is where abouts in the src tree should I look, i.e. what 
files need to be modified. Also does anyone have any opinions on whether 
or not what I am trying to do is possible.

Patrick Collins
pc012@seqeb.gov.au