Minecraft wiki entry for Morse_code, associated text: You will notice that at 'B' there is four repeaters delaying the message to the 3rd input this is because you need to allow time, if it’s there, for the dash to pass through and then block the gate so it can no longer be affected by any other impulse. The rs-nor 'C^' which activates the 3rd input also goes into another and gate which when the next impulse comes through will allow the signal to pass and go the same process again as before.