Richards controller

The Richards controller is a method of implementing a finite-state machine using simple integrated circuits and combinational logic.

It allows for easier design of complex finite-state machines than the traditional techniques of state diagrams, state-transition tables and Boolean algebra offer.

Using Richards's technique, it becomes easier to implement finite-state machines with hundreds or even thousands of states.

Because of this, Charles L. Richards invented a method of implementing a finite-state machine that did not need an explicit state-transition table.

[citation needed] His generalized implementation became popular and by the 1980s was considered a classic design method.

The machine considers executing a function to be setting the output of a single pin on the device, this can be used to trigger combinational logic.

A simple controller can be built using the classic 7400 series of TTL logic integrated circuits.