Path: utzoo!attcan!lsuc!dave
From: dave@lsuc.uucp (David Sherman)
Newsgroups: comp.dcom.modems
Subject: Re: Packet Switching (X.25) and BBS
Summary: you can make UNIX accessible via X.25
Message-ID: <1988Sep25.001151.6452@lsuc.uucp>
Date: 25 Sep 88 04:11:50 GMT
References: <62@csnz.nz>
Reply-To: dave@lsuc.UUCP (David Sherman)
Organization: Law Society of Upper Canada, Toronto
Lines: 44

In article <62@csnz.nz> paul@csnz.co.nz (Paul Gillingwater) writes:
>3) I understand that classic BBS usage requires character-based connection,
>   so that the BBS can support interactive editing and word-wrap.  X.25
>   however is more suited for line-based usage, sending a packet for each
>   line that is transmitted.  Clearly, character mode connections are much
>   less efficient - is there any BBS software that will cope elegantly with
>   line-based interaction?   Will this impinge upon, e.g. ZMODEM transfers?

We've been running a UNIX system that's accessible via Datapac,
the Canadian X.25 network, since 1984.  It's a v7-based system
(Perkin-Elmer 3220).  Our users include students located across
the province of Ontario (and, in some cases, across the country)
doing CAI courses, and staff in our Ottawa and London, Ontario
offices, doing database access, email, some editing, and "notes"
(internal computer conferencing).  None of the out-of-town staff
use Usenet much.

To avoid ridiculous charges, you do indeed need to operate on a
line-by-line basis.  We set up our calls (using X.29 to set the
remote PAD when the call comes in) to have a packet transmitted on
CR or any control character; that allows interrupt chars such as
DEL, ctrl-C or ctrl-\ to send the packet.

We make do fine with line-based editors (a souped-up version of
"ed", the University of Toronto ed), a line-based version of
"notes", etc.  A few things aren't quite as pleasant, but on
the whole it functions fine.  You have to make sure you turn on
echo on the caller's PAD (have them do it themselves or you do
it for them with X.29), and stty -echo at the UNIX end.  I have
some hacks to login, passwd and similar tools (actually a change
to getpass(3) catches all of these) to change the concept of
"turn echo off" for PAD lines to mean "send an X.29 instruction
to turn echo off at the far end" rather than "stty -echo".

If you want to run "notes" for your BBS software, I have a hacked-up
version that greatly simplifies all the commands, and uses line-based
interaction only.  It's based on the version of notes that was current
in the fall of 1984.

David Sherman
The Law Society of Upper Canada
Toronto
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