Abstract: An input command controller (A) provides logic function selection signals and proportional signals. The signals are generated by movement of a ball member (12) and socket member (14) relative to two orthogonal axes. When the joystick is implanted, a transmitter (50) transmits the signals to a patient carried unit (B). The patient carried unit includes an amplitude modulation algorithm such as a look-up table (124), a pulse width modulation algorithm (132), and an interpulse interval modulation algorithm (128). The algorithms derive corresponding stimulus pulse train parameters from the proportional signal which parameters are transmitted to an implanted unit (D). The implanted unit has a power supply (302) that is powered by the carrier frequency of the transmitted signal and stimulation pulse train parameter decoders (314, 316, 318). An output unit (320) assembles pulse trains with the decoded parameters for application to implanted electrodes (E).