by Brian James Parry
Brian J. Parry is a computer science student at the California State University, Chico. He has published several programs for the Apple II and this is his first Atari ST program.
Merlin's Box is a single-player game in which you try to locate several glass spheres. The spheres are hidden within Merlin's Box and cannot be seen from the outside. Clues to where the spheres are located are obtained by shooting a light into the box and noting where it exits, if at all. When you believe you have located all the spheres, their correct locations will be revealed. Based on the number of correct choices, you will be given a score from 0 to 100, 100 being the best.
To create your copy of Merlin's Box from the program listings included here, you must first type and compile each listing. (Listing 1 requires Personal Pascal compiler and Listing 2 requires an assembler.) After compilation and assembly, you should have two files with a .O extension. Use the Personal Pascal linker to link these files. You will then have an executable .PRG file that can be run from the desktop.
Playing the Game
Merlin's Box is a low-resolution color game, so make sure you are in low-resolution mode. Double click on MERLIN.PRG. When the title screen appears, click on the OK in the title box. Next, you will be asked to choose a skill level, 1 through 3. In skill Level 1 you must locate three spheres, with Level 2 locate five spheres, and Level 3 locate seven spheres. Level 1 is pretty easy because there is less deflection from other spheres to confuse you. The seven spheres in Level 3 tend to bounce light around before it leaves the box, making for a few misjudgments as to the locations of the spheres.
Once a level has been chosen, the spheres are randomly placed and the box is drawn. On each side of the box are eight positions from which to shoot light into the box. To shoot light click on one of these outside squares. A symbol will mark the entrance, and you will hear the light enter the box, bounce around and exit.
When the light enters the box it can exit one of three ways. First, it can be deflected or go straight through, in which case a matching symbol will be displayed at its exit position. Second, it can exit where it entered. Here, a U-turn symbol will be placed. Last, the light can directly hit a sphere and be diffused throughout the box and not be strong enough to exit. In this last case a "Hit" symbol will appear. Please refer to Figure 1 for an illustration as to how the light can act inside the box. One situation not yet mentioned is a Stall. Here the light is not able to enter the box because of an adjacent sphere. Stalls can be determined because no exit position is shown and neither a U-turn nor a hit is displayed.
To guess where a sphere might be, click on one of the 64 squares in the box. A circle will appear marking your guess. If you wish to change your guess, click again on the circle, and it will disappear. You can then reposition your guess. In the lower left corner of the screen is the number of spheres in the box. You must make a guess for all of them before obtaining your score.
To get your score click on "SCORE" in the upper left of the screen. One by one the spheres will appear as either green or red. Green spheres mark a correct guess while red ones mark an incorrect guess. Your score will appear in the lower left of the screen. After a few games you will get the hang of it and then it will be time to move up a skill level. You can quit any time by clicking on "QUIT" in the lower right corner. Lastly, a hint. For those of you who are good listeners, try to listen to how and when the light deflects. The sounds come fast but can aid in locating tricky spheres.