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From: MRC@PANDA.COM (Mark Crispin)
Newsgroups: comp.protocols.tcp-ip
Subject: Telnet binary mode
Message-ID: <12309935927.8.MRC@PANDA>
Date: Fri, 12-Jun-87 12:17:39 EDT
Article-I.D.: PANDA.12309935927.8.MRC
Posted: Fri Jun 12 12:17:39 1987
Date-Received: Sat, 20-Jun-87 21:03:05 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 29

All Telnet servers should have a command that a network user can issue
that puts the network terminal in binary mode.  PANDA TOPS-20's have
the command TERMINAL [NO] NETWORK-BINARY [INPUT | OUTPUT | BOTH].

All Telnet clients should have a command that a Telnet user can issue
that puts the Telnet connection in binary mode.  TOPS-20 TELNET has
an escape sequence and a command to put the connection into so-called
"transparent mode."

Binary mode should never, ever, be done automatically by either a
host or a client unless it is damned sure that 8-bit I/O is what is
wanted.  It must never, ever, be a side effect of some data that a
user outputs (e.g. an FFh character output by a user program must be
doubled by the operating system and not allowed to be interpreted as
a Telnet protocol command).

Binary mode should never, ever, be tied to the host's concept of a
terminal in binary mode (Unix calls this "raw" as opposed to "cooked"
mode).  Certain inferior losing versions of Unix and TOPS-20 both do
this -- most of the turkey TOPS-20 implementations have been exterminated
but there are still many turkey Unix implementations out there.  Being a
turkey leads to the infamous "new Telnet rubout performance problem" of
the late 1970's plus confusion Unix newline confusion.

Implementation details of the TOPS-20 code on request; I wrote it.  The
only TOPS-20's with correct servers are SIMTEL20, STL-HOST1, and DREA-XX;
all other TOPS-20's have either completely broken servers or servers with
half-assed fixes (e.g. Stanford TOPS-20's).
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