2.11BSD#431 - /usr/man/cat1/tn3270.0

TN3270(1)	    UNIX Programmer's Manual		TN3270(1)


NAME
     tn3270 - full-screen remote login to IBM VM/CMS

SYNOPSIS
     tn3270 sysname

DESCRIPTION
     Tn3270 permits a full-screen, full-duplex connection from a
     VAX UNIX machine to an IBM machine running VM/CMS giving the
     appearance of being logged in directly to the remote machine
     on an IBM 3270 terminal.  Of course you must have an account
     on the machine to which you wish to connect in order to log
     in.  Tn3270 looks to the user in many respects like the Yale
     ASCII Terminal Communication System II.  Tn3270 is actually
     a modification of the Arpanet TELNET user interface (see
     telnet(1)) that interprets and generates raw 3270 control
     streams.

     Emulation of the 3270 terminal is done in the Unix process.
     This emulation involves mapping 3270-style commands from the
     host into appropriate sequences to control the user's termi-
     nal screen.  Tn3270 uses curses(3x) and the /etc/termcap
     file to do this.  The emulation also involves simulating the
     special 3270 keyboard keys (program function keys, etc.) by
     mapping sequences of keystrokes from the ASCII keyboard into
     appropriate 3270 control strings.	This mapping is terminal
     dependent and is specified in a description file,
     /usr/share/misc/map3270, (see map3270(5)) or in an environ-
     ment variable MAP3270 (see mset(1)).  Any special function
     keys on the ASCII keyboard are used whenever possible.  If
     an entry for the user's terminal is not found, tn3270 looks
     for an entry for the terminal type unknown. If this is not
     found, tn3270 uses a default keyboard mapping (see
     map3270(5)).

     The first character of each special keyboard mapping
     sequence is either an ASCII escape (ESC), a control charac-
     ter, or an ASCII delete (DEL).  If the user types an
     unrecognized function key sequence, tn3270 sends an ASCII
     bell (BEL), or a visual bell if defined in the user's
     termcap entry, to the user's terminal and nothing is sent to
     the IBM host.

     If tn3270 is invoked without specifying a remote host system
     name, it enters local command mode, indicated by the prompt
     ``tn3270>''.  In this mode, tn3270 accepts and executes the
     following commands:

	  open	    connect to a remote host
	  close     close the current connection
	  quit	    exit tn3270
	  z	    suspend tn3270


Printed 11/26/99	November 27, 1996			1


TN3270(1)	    UNIX Programmer's Manual		TN3270(1)


	  status    print connection status
	  ?	    print help information

     Other common telnet commands are not available in tn3270.
     Tn3270 command mode may also be entered, after connecting to
     a host, by typing a special escape character (typically
     control-C).

     While in command mode, any host login session is still alive
     but temporarily suspended.  The host login session may be
     resumed by entering an empty line (press the RETURN key) in
     response to the command prompt.  A session may be terminated
     by logging off the foreign host, or by typing ``quit'' or
     ``close'' while in local command mode.

FILES
     /etc/termcap
     /usr/share/misc/map3270

AUTHOR
     Greg Minshall

SEE ALSO
     mset(1), telnet(1), termcap(3x), termcap(5), map3270(5),
     Yale ASCII Terminal Communication System II Program
     Description/Operator's Manual (IBM SB30-1911)

BUGS
     Performance is slow and uses system resources prodigiously.

     Not all 3270 functions are supported, nor all Yale enhance-
     ments.


Printed 11/26/99	November 27, 1996			2