PPK allows you to peek at the screen of someone at a display terminal
(a DataDisc, III or Datamedia).  Say "R PPK", and give it the line
number of the terminal you want to observe.  (For DataDiscs, this is
NOT the number reported by FINGER; it's the number following the PPN
in the person's wholine, and can be found with the WHERE command.)
If you are on a display yourself and have your wholine turned on, PPK
changes your wholine to be that of the job at which you're peeking.
(Your original wholine selection is restored when you exit.)

Once you have selected a line, if the user is editing with E, you can
type the letter E to observe the edit.  N returns you to the normal
"observe page printer" mode.  (Do NOT follow the E or N with a
carriage return, or PPK will exit!)  Typing another line number
followed by a carriage return gets you another victim.  A raw carriage
return causes the program to exit.

If the selected terminal is hidden (by ESC H), PPK will so notify you.
You may choose to override the hiding, but if so, the selected terminal
is notified that you are spying on it.

The display is updated about once every two seconds.  You can force an
immediate update by typing ALTMODE.  You can also set the rate by
typing control-meta-digit, where 1-9 = 1-9 secs and 0 causes the
display never to be updated (except when you type ALTMODE).

Do HELP PK for information on a related "spy" program.