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C00002 00002	This writeup attempts to explain the privacy, spying, and mapping
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This writeup attempts to explain the privacy, spying, and mapping
features of the system.


PRIVACY

A user can request privacy for his terminal, no matter what kind
of terminal he is on.  The command ESCAPE H (and the monitor
command TTY ESCAPE H) sets the privacy flag for your terminal.
BREAK H (and TTY BREAK H) clear the privacy flag.  When the
privacy flag is set, the system (and soon certain system
programs) will NORMALLY not allow anyone to spy on your terminal.
Furthermore, anyone spying on your terminal when ESCAPE H is
typed will be stopped from doing so.

The state of the privacy flag for any terminal can be retrieved
with the TTYSET UUO, function 20 (octal).  The (soon to be made
public) system programs that spy on terminals will use this UUO
to decide when they shouldn't spy unless asked to ignore privacy.

The privacy flag of an available terminal is always off.


RESPONSIBLE TERMINALS

THE TERMINAL RESPONSIBLE FOR A PRIVATE TERMINAL IS NEVER
OBSTRUCTED FROM SEEING THE PRIVATE TERMINAL.  The responsible
terminal is defined to be the last physical terminal that typed a
characters (while mapped) to the logical terminal.  Letting a
private terminal be seen by its responsible terminal allows you
to map away from your local DD terminal and type ESCAPE H to
protect the remote terminal and still be able to map back and
forth without needing to override the privacy flag.

No one is responsible for an available terminal, unless the
terminal is a DD in the DD channel wait queue, in which case the
DD that put it there is responsible.


OVERRIDING PRIVACY

PRIVACY IS NEVER GUARANTEED!  The privacy flag can be overridden
by a spy who explicitly asks to do so.  However, even such a spy
is stopped from spying on your terminal (at least momentarily)
whenever you type ESCAPE H (although he can then ask again to
override the privacy flag).


SPYING ON DATA DISC TERMINALS AND CHANNELS--MAGIC COMMANDS

Most of the DD mapping, tying and video commands can be given
with a special version of ESCAPE to override privacy requests.
This special version shall be called MAGIC for short.  Normal
ESCAPE and BREAK commands observe privacy requests, but MAGIC
commands do not.  Thus you can map to a private DD terminal by
typing what we will call MAGIC # M, and you can tie your DD to
the DD map of a private DD with MAGIC # L.

NOTE: IT IS CONSIDERED A GRAVE VIOLATION OF ETHICS TO SPY ON
SOMEONE ELSE'S PRIVATE TERMINAL UNLESS YOU HAVE SOME VERY
COMPELLING REASON (for example, the guy whose terminal it is asks
you to look at his terminal).  The MAGIC commands should
therefore not be used as a matter of habit.  People caught
randomly spying on private terminals will be censured (at least).
If you see someone randomly spying on private terminals, please
point out that this is not acceptable behavior; if he continues,
bring this fact to the attention of the "higher ups" (e.g., LES).

To get MAGIC, type

	CONTROL-META-TOP-UNSHIFT-BREAK

instead of ESCAPE or BREAK (being sure to turn off SHIFT-LOCK).
MAGIC always executes the ESCAPE version of a command instead of
the BREAK version, except for the L command, where it does the
BREAK version (to tie your DD to the DD map of another DD
terminal).  Thus you CANNOT type MAGIC versions of the commands
BREAK # S, BREAK # T, and BREAK # A (this might change).

Thus the commands that accept MAGIC instead of ESCAPE or BREAK are:

	ESCAPE # M	ESCAPE M
	BREAK # L	BREAK L
	ESCAPE # S
	ESCAPE # A
	ESCAPE # T


COMING SOON: SYSTEM PROGRAMS FOR SPYING

Soon, certain programs will be made public which allow spying
on any terminal (especially non-DD terminals or from non-DD
terminals).  These programs will observe the privacy flags of
terminals being spied upon except when the user specifically
asks to override privacy.  As with the MAGIC commands, use
of these programs to override privacy without a valid reason
is considered unacceptable behavior.