but it does contain an SR latch, which only requires a little persuasion to become a JK flip flop. His initial design for the flip flop that would form the core of the circuit had a pair of 555s ...

The diagram to the right is in falstad or using Verilog ... together (see below). The JK flip flop sounds mysterious, but it really isn’t. Think of it as an SR flip flop where the J input ...