Machine features two 4 Bit Inputs, A and B and 4 functions, Add, Subtract, Multiply, and Divide. The adder/subtractor unit uses Insta-Carry addition, with XORs for toggled invert when subtracting. The subtracting uses two's complement to make b a negative number. The multiplier is a combinational hardwired circuit that uses ICA adders, and the divider is also hardwired with ICA subtractors.
Select a function on the right wall with one of the levers. Then go to the front wall and choose your inputs. The inputs are 4 bit binary numbers. A is on top and B is on bottom. The answer is on the left wall. The bottom output is just the regular outputs for all circuits. The top row of lights is the division remainder.