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File: TELNET	Node: Top	Up: (DIR)

     TELNET is a program to communicate with other hosts on the
Internet or MIT's Chaosnet.  It is intended primarily for communicating with
non-MIT hosts; a special TELNET program, SUPDUP, exists for communicating
which hosts which support the ITS "SUPDUP" display protocol.  Most MIT hosts
support SUPDUP, save for a few small Unix machines, some Lisp Machines,
Multics, and hosts that run VMS.  SUPDUP is also supported by S1 and SU-AI.
SUPDUP is the preferred method of getting from one place to another, since
one does not (ordinarily) have to manually set the terminal type on the other
host.

* Menu:

* Telnet: TELNET	General-purpose TELNET
* Supdup: SUPDUP	SUPDUP (the SUPer DUPer network terminal protocol)

File: TELNET	Node: TELNET	Next: SUPDUP	Up: Top

     When TELNET is started, it first checks for JCL passed from
DDT.  If there was JCL, it is taken as a host name to connect to.
Otherwise, if the job name is not one of {TN, TELNET, xTN,
xTELNET~, the job name is interpreted as JCL and the JCL action
applies to it, else, the user is placed in TELNET command mode.
In TELNET command mode the user may enter any of the commands
listed below, subject to restrictions noted with the command.  If
a command or any part of a command is invalid, TELNET will refuse
to echo the offending character.  Confirms may be flushed by any
character other than 'Y', 'y', ' ', or <cr>; an 'O' command may
be flushed by a rubout.

     An exception to the JCL convention listed above is that "?"
typed as a JCL argument automatically does a Help command.

     When a connection is open ("talk mode"), the intercept
character (normally <CONTROL>^ on non-TV's, [BREAK] on TV's) will
put TELNET in command mode for a single command.  Unless that
command closes the connection or returns to DDT, following
execution of the command the user is returned to talk mode.  If
no connection is open, a command will simply return, causing
another command to be prompted for.  In talk mode, command
prompts are homed down to the bottom of the screen.

     The "H" command and the [HELP] key will output an incredibly
long help message telling everything you never wanted to know
about how to use TELNET in every hairy way imaginable. 

File: TELNET	Node: SUPDUP	Next: CMNDS	Up: Top

     The SUPDUP program can be used to log in to most MIT
systems and SAIL over the network.  The other system is informed
of your terminal type so that you get all the facilities
available locally.  In particular, if you are at a display
terminal TECO ^R mode will work, etc.

     The :AI, :MC, :ML, :OZ, :XX, or :SAIL commands may be used to get
to the AI, MC, ML, OZ, XX, or SAIL systems, respectively, or the
:SUPDUP command may be used.  The latter asks for a host name.

     There is one character which is intercepted by SUPDUP so
that you can give it commands.  The character is <CONTROL>^ on
regular terminals, and [BREAK] on TVs.  All other characters are
sent through to the net, including ^Z and ^_ !!  So to get out of
the program, do a <CONTROL>^ or [BREAK] followed by L (for
Logout).  This logs you out on the other end.  To get out
temporarily (what ^Z would do to other programs), say "D" instead
of "L".

     There are more commands, documented in the next node.

     If your connection is broken for any reason, INCLUDING the
"Q" command, but not including the "L" or "Logout" command, the
job on the other system will be detached.  You have an hour to
come back and claim it (log in again and DDT will say --ATTACH
YOUR DETACHED JOB-- and you reply space.)  If you don't pick up
the job within that time it will be flushed.  

File: TELNET	Node: CMNDS	Previous: SUPDUP	Up: SUPDUP

SUPDUP Commands:

     All characters including ^Z and ^_ work through the network, except for
^^ (ctrl-circumflex or ctrl-shift-N) on regular terminals, and [BREAK] on TV
terminals.  (N.B.  On some terminals, like VT100s, control-^ is actually
typed in as control-`.)  This character is an escape to "command" mode; it
types "Cmnd -> " and you may now type a one-letter command:

	Q closes your connection and :KILL's.  :LOGOUT first!!

	L is like Q but automatically logs out your jobs at the
	  other end.

	D gets back to DDT without closing the connection; p to
	  resume talking to the other system.

	^Z does local ^Z (same as D).

	C allows you to change the command character if you use
	  ^^ (or [BREAK]) too much to waste it on this.

	G enters a mode where ^G and ^S are assumed to mean "stop
	  typing."  If you type one of these characters, SUPDUP
	  will send it through but it will locally inhibit
	  typeout until you type another character.  This is to
	  provide fast response on slow terminals.  Another G
	  command turns the mode off again.

	? gives brief help.

	The command character sent as a command sends itself to
	the remote site.  Anything else is ignored.

     After you type your one command the cursor goes back to
where it was and you are back in normal mode.

     On TV terminals the various control and meta keys all work
just as they do locally.  Note that the initial command character
is BREAK rather than CTRL/^.

     On non-TV terminals the control characters are translated
into the upper-case ASCII controls of the 12-bit TV character
set.  This includes the RETURN and ALTMODE keys; note that the
TVs give different codes for RETURN and CTRL/M.  However, this is
the proper thing for Teco ^R mode.
