     
     The Blackbox program may be played in two modes.  In mode 1, the program 
places the hidden marbles in the 8 * 8 grid using a random number generator. 
In mode 2, a player may place marbles for an opponent to guess in the 8 * 8
grid.  In either mode, the player may select either 4 or 5 marbles to be
hidden in the grid.  The score of the game is the sum of the markers denoting
the number of rays needed to deduce the position of the marbles in the board.

     The commands to Blackbox are S(hoot, which fires a ray from a player 
selected row or column; M(anipulate Marbles, where the player may place
marbles to indicate a tentative guess; and G(uess when a player decides that 
his tentatively placed marbles represent a correct guess.  If the guess is 
correct, the game ends and the score is displayed.  The score is the sum of 
the markers '*','^', and 'a','b',etc.  If a guess is incorrect, a 5 marker 
penalty is added  and the game continues.

     Type <return> to start the game.

     
