Pull Down Lever For Highest Score! This Elektor Circuit Classic from 1984 shows a playful application of CMOS 400x series logic ICs in combination with LEDs, a highly popular combination at the time. The project imitates a spinning-digit type slot machine. The Game To play the game, first agree on the number of rounds. Player 1 actuates the switch lever as long as desired and releases it. The LEDs then show the score which is the sum of the 50-20-10-5 digits lit up. If the Play Again! LED lights, Player 1 has another, “free” round. If not, it’s Player 2’s turn. The players keep tab of their scores, and the highest score wins. Features LEDs Indicate Score Multi-Player and Play Again! Elektor Heritage Circuit Symbols Tried & Tested by Elektor Labs Educational & Geeky Project Through-Hole Parts Only Included Printed Circuit Board All Components Wooden Stand Bill of Materials Resistors (5%, 250 mW) R1,R2,R3,R4 = 100kΩ R5,R6,R7,R8,R9,R10 = 1kΩ Capacitors C1 = 4.7nF, 10%, 50V, 5mm C2 = 4.7μF, 10%, 63V, axial C3,C4 = 100nF, 10 %, 50V, ceramic X7R, 5mm Semiconductors LED1-LED6 = red, 5mm (T1 3/4) IC1 = 74HC4024 IC2 = 74HC132 Miscellaneous S1 = switch, toggle, 21mm lever, SPDT, momentary S2 = switch, tactile, 24V, 50mA, 6x6mm S3 = switch, slide, SPDT IC1,IC2 = IC socket, DIP14 BT1 = PCB-mount CR2032 battery retainer clip Desktop Stand PCB 230098-1 Not included: BT1 = CR2032 coin cell battery