The multiplier is ready for input when the green LED is on. Enter the operands with a group of 4 push buttons. Click the button on the right to get the result.
This circuit also demonstrates problems related to a) delay in carry signal propagation and b) asynchronous reset :D To see this, run F x F = E1 calculation a few times and observe the scope.
There is the 2nd version which is free of these problems: http://everycircuit.com/circuit/5151469049741312
