any one who can help is greatly appreciated. the simulation for the lamp handball experiment which is the basis for our real project is not working. It's done in multisim and i'm at wits end. I just can't get it to run and i'm a total beginner in using multisim. i've attached the file, the logic diagram and a photo of a circuit of the said experiment but they used a 555 timer which I don't get the function in the experiment. please help. the presentation of the project is on monday and this is the only part that's not working so the circuit works like this. first, it is initialized with the reset switch. the start switch starts the game by placing the ball(a probe) at the extreme right. the user must press the pulser push button to start the ball moving to the left. the single light shifts to the left until it reaches the leftmost position at which time the ball returns to the user by reversing the direction of the shift of the moving light. when the light is again at the rightmost position, the user must press the pulser again to reverse the direction of the shift. if the user presses too soon or too ate, the ball disappears and the light goes off. the game can be restarted by turning the start switch on and then off. the start switch must be open(logic 1) during the game. i've done the rest of the connections except for the pulser part. is the use of the bus vector connector correct?i just copied it from the sample simulation of a shift register done in multisim too.