There is disclosed herein a new form of electronic ignition apparatus and system including an integral sensor/electronics module, and adapter plate therefor, which can be mounted within a conventional distributor in direct replacement of conventional breaker points not requiring any modification to the distributor or vehicle wiring system. The apparatus also includes a rotor, similar to a conventional distributor rotor, but which includes a plurality of permanent magnets secured thereto or imbedded therein. Upon rotation of the rotor, timing signals are generated by the sensor as a function of rotor position, and the electronic module provides electronic switching pulses suitable for switching the primary of the ignition coil of a vehicle. Several rotor and adapter plate configurations are described for enabling conversion of different existing vehicles from a conventional breaker point type ignition system to an electronic ignition system.