Path: utzoo!utgpu!watmath!looking!brad
From: brad@looking.on.ca (Brad Templeton)
Newsgroups: comp.unix.xenix
Subject: Re: dial and bidirectional _direct_ uucp lines
Message-ID: <3960@looking.on.ca>
Date: 8 Aug 89 03:04:09 GMT
References: <2121@csuna.csun.edu>
Reply-To: brad@looking.on.ca (Brad Templeton)
Organization: Looking Glass Software Ltd.
Lines: 22
Class: information, original

A bidirectional line is quite difficult without a modem.
You would need some fancy software.

The problem is that unlike with the modem, carrier detect will
always be present.  So each line, which as a Getty on it, will always
have the getty active.

Put two getty's at one another and it's real fun.  The first asks for
a login, and the second does two, except that gets taken as a userid, and
then the word "Password:" is taken as a userid on the other system etc. etc.

You need a silent getty that doesn't print any prompt, and even then
it's tricky.

As the port is always open, you have to be able to tell between a getty
that has the port truly open and a user on the port.  Otherwise you can't
know when it is safe to turn it around.

Sounds like a good TCP/IP with SLIP would be the right answer.  But
very few tcp/ip makers include SLIP.   I think SCO does, now.
-- 
Brad Templeton, Looking Glass Software Ltd.  --  Waterloo, Ontario 519/884-7473