/CHAT_TOGGLE = "hot-key-defintion"

   Allows the watcher and user to enter a chat, where they can type back
   and forth to each other, but the keystrokes typed are not entered as
   input to whatever program the user process is running.

   Specify a sequence which when pressed by the watcher will cause
   Peek/Spy to enter a mode which is similar to "local mode" on a
   standard terminal. In other words, what the watcher types while
   watching a user will be echoed on both terminals, but will NOT
   be placed into the typeahead buffer or passed to any other program.
   This prevents this type of activity from causing program or command
   errors.

   The logical WATCHER$CHAT_TOGGLE defines the default hot-key value.

   Example:

         $ PEEK JONESIE /CHAT="<F14>"
     or
         $ DEFINE WATCHER$CHAT_TOGGLE "<F14>"
         $ PEEK JONESIE

   Whenever the watcher presses F14, both terminals will go into chat
   mode. You may at this point type whatever you wish, and it will be
   displayed on both screens.

   If it appears not to work and your terminal just beeps when you type,
   this is because you do not have keyboard input control (see the PEEK
   Watching Subtopic: /TOGGLE_INPUT, which is still active during chat
   mode unless /SIMULTANEOUS_INPUT is in effect).

   The keys which are useful while in chat mode are the alphanumeric
   keys, carriage-return, delete and the arrow keys.

   You should press carriage-return to end a line, since if the other
   terminal is not in auto-wrap mode, the other user may not be able to
   see what you are typing after you reach the margin and your terminal
   does do an autowrap.

   If your terminal displays "hieroglyphics" in chat mode, it is likely
   that the terminal has the line-drawing character set selected. In this
   case, pressing the shift lock key will cause subsequent characters to
   be displayed normally.