Copyright (C) 1978 William A. Kornfeld

            CHASE - A Real Time game for VT52's

CHASE is real time game (e.g. space war, MAZE, etc.) with the distinction that
it is played on a VT52.  The game is played by two players who must both be
present at the same physical terminal.  It can in principle be used on other
character display terminals but may require redesignation of some of its
command characters to retain their current positional mnemonic significance. 
CHASE can be played over phone lines with as little as a 300 baud modem or over
the net (though response may be somewhat unsatisfactory). 


To setup a VT52 for CHASE make sure of the following:

     1. CAPS LOCK is set!

     2. The terminal is not in one of the VT52's special modes (i.e. graphics
        or alternate keypad).  This can be assured by momentarily turning off
	power to the terminal.



After the game has begun you will notice a maze appear on the screen and
four characters: X,x,O, and o.  The two X's are controlled by the person on
the left side of the terminal and the O's by the person on the right side.
The two large letters are known as "chasers" and the two small letters as
"chasees".  The object of the game is to have your chaser "catch" (bump
into) the opponent's chasee.  The game can be thought of as two simultaneous
chases happening concurrently in the maze.  Each player plays both offense
and defense.  Each player specifies directions for the two pieces under
his/her control.  They may move anywhere in the maze as though they cannot
be moved through the wall of the maze.  There is one additional constraint:
a chaser cannot move through the opponents chaser nor a chasee through the
opponents chasee.  In addition to a pieces normal function it can also be
used to block.  In this way the two chases interact and can lead to
sophisticated strategy with experienced players.

Pieces can be made to move in any of four directions (or held in place) by
appropriate keystrokes.  Once a piece is put into motion it will remain in
motion at a constant velocity (same for all pieces at all times) until it is
explicitly told to stop or it reaches an obstruction which it cannot pass.
Each piece is controlled by a group of four keys (one for each direction)
arranged so that the players do not have to watch the keyboard as they enter
commands.  In each group of four keys 3 are at the same level and 1 is directly
above the middle of the 3 keys.  The lower 3 keys are respectively left, down,
and right.  The upper key is up.  The middle 3 fingers of each hand should be
placed on the 3 keys.  In this way commands may be entered easily.  As an
example the X piece is controlled by the four keys: A,S,D, and W.  The middle 3
fingers of the left hand of the X-player should be placed on A, S, and D.
Hitting D once will start the X piece going right until it either hits
something or another command is given.  Similarly for A, S, and W with left,
down, and up.  The four command pads are:

          BIG-X                     little-x

           A			       T

        S  D  W                     F  G  H



          BIG-O			    little-o

           [			       8

         ; ' {                       4 5 6

				     ^^^^^These four numbers are typed on
					  typed on the numeric keypad to the
					  right of the normal keypad.

If a piece is going in a direction, giving the command to travel in the
opposite direction once will stop the piece.  Giving it twice will start the
character in the opposite direction.  If a piece is going in a direction and
the command is given for it to go in an orthogonal direction it will
immediately start in that direction.  Note that if a piece has been travelling
in a direction and hits an obstruction (usually the wall of the maze) it will
act as if it is still going in that direction with respect to future commands.

Games continue until a chaser has caught a chasee.  The program pauses then for
a few seconds to report the victor and the score.  When done it prints "READY".
Hitting RETURN will start a new game (with the initial positions of pieces
switched to be fair).  If the display gets screwed up for any reason hitting
LINEFEED will freeze the game and do a redisplay.  If the program screws up, it
may be started fresh from the top level LISP by typing (CHASE).

It doesn't take long to get reasonably comfortable with the controls.  It is
easy however to get confused as you control the two pieces simultaneously.
Part of the skill to develop is in how to overcome this confusion.  This also
enters into strategy.  You can count on your opponent to get confused in
certain positions and can take advantage of that fact.  This happens, for
example, when his/her 2 pieces cross paths or when they are both in opposite
parts of the maze and doing difficult manuevering.  Strategy also includes
using your chaser to block the opponents chaser on defense and using your
chasee to block the opponents chasee on offense.  It is important to always
remain on the offense.  Beginners quickly give up offense when the going starts
getting rough.  This only makes things worse in the end.

There is one unfortunate bug that I have not exorcised where the program
breakpoints just before restarting the game.  If this happens just hit
CTRL-G and then type (CHASE) for a refresh.  

This game is protected by US Copyright.  No implementation may be undertaken
for any commercial purpose without prior consent from William A. Kornfeld.