"O-Jello" By Clyde Perkins 1980 [This is a transcription of the audio rules that Clyde Perkins placed before and after the "O-Jello" BASIC program. If you would like to listen to the audio rules spoken by Mr. Perkins, then they are available on BallyAlley.com.] This tape contains a program in Bally BASIC for a one or two-player game I call "O-Jello." It was inspired by an excellent article in the November issue of "Byte" by Peter Maggs [Maggs, Peter B. "Programming Strategies in the Game of Reversi," Byte, Nov. 1979, 66-79.]. It is a board game about a hundred years old called reversi recently marketed under the registered trademark "Othello." Rules for the game are as simple as checkers but playing strategy can be as complex as Chess. Let's take a look at the board. I'll give you about ten seconds to prepare to input the program. When it automatically runs and asks, "HOW MANY PLAYERS?", stop the tape and input a 1, followed, of course, by GO. When you see the cursor blinking in the center of the board, start the tape again. Here we go... [The end of part one of the "O-Jello" rules is "Here we go." The Bally BASIC game follows in 300-Baud on the tape. The game is followed by the second part of the rules, which you're expected to listen to after "O-Jello" has loaded and play has begun. Now begins the part two of the rules.] The computer has already made the first four plays at the center of the board. Two white pieces for you; two black pieces for itself. The arrow at lower-left indicates that it's your turn. The flashing cursor at the center of the board can now be moved using joystick #1. Move the cursor to an empty square next to a black piece in such a way as to enclose the black piece between the cursor and one of the white pieces already on the board. Now pull the Trigger. You have now placed a new white piece at that location and the captured black piece flipped over to become white. The score is now four to one. While the computer picks out its best move, let's look at the rules. A play is always made by choosing an unoccupied square that will result in an unbroken, straight line of playing pieces, with one of the players own pieces at each end, and one or more of the opponents pieces in the middle. This straight line may be horizontal, vertical, or diagonal. Later in the game you'll see that a move may result in several straight lines, each in a different direction. Squares along an edge are usually valuable to take, and corners are especially good. Eventually you may find you can't make a legal move and must pass, or you may feel so lucky, you want to pass and give the computer the first play of the game. To pass a turn, move the cursor off the board on any side and press the Trigger. The game is over when neither player can play. Press any key to run it again. Now, here's some good news. If you're tired of my voice and understand how to play, try the flipside of the tape the next time you want to play "O-Jello." A word of caution if you like to alter programs: SZ must read above 131 or the program will not run. Deleting the first three lines will give you over 75 bytes to play with. Credit must go to a fellow subscriber, my son, John Perkins (of Virginia Beach, Virginia), for help with the program, especially with cutting the search time by a factor of four. Line 10 puts up the board, and 20 places the first few pieces (also the scores). In the one-player mode, lines 30-50, setup the computer's strategy. Play starts at 60, with 70 giving control of the flashing cursor to the proper joystick. 80 finds the center of the chosen space and 90 aborts to 110 if you choose an occupied piece. 100 changes players. Lines 110-130 tell you, you goofed, but give you another chance at line 70. 150 begins the computer's play. 170 goes to 190 to end the game if both players pass. 180 also falls to 190 if all spaces are filled. There are too many branches and subroutine calls to give complete, line-by-line documentation, but the next 14 lines search the entire board. Starting at the upper-left corner, spaces are checked rapidly with a forward, fan-shaped search (like aircraft radar). When an opponent's piece is encountered, the search pauses, and investigates a line in the direction of the piece. Legal plays are noted and strategic values compared with previous finds so the computer can choose the best move. Lines 340-380 place the new piece and then flip all captured pieces and change the scores. 390 gets strategic values from memory. 400 flashes a box as each new direction is investigated. 410 moves the arrow when players change, and 420 changes the computer's strategy during play. Copies of this tape are going to Bob to print in the "Arcadian" and to Steve Wilson in Cleveland, Ohio for review. When evaluated, I intend to sell this tape for $4.00, or copy it on a subscriber's tape for $3.00. (Audio Transcription by Adam Trionfo, September 27, 2012)