1. An electrical stimulator of biological tissue of a user useful for operable muscle stimulation and for transcutaneous electrical nerve stimulation (TENS) for pain control, comprising: storage means for storing a plurality of sets of stimulus parameters; converting means for converting a selected one of said plurality of sets of stimulus parameters to an electrical stimulus output signal which is adapted to be supplied to biological tissue; remote means for communicating in real time a digital signal from a response from said user to said electrical stimulator to change at least one of said stimulus parameters of said electrical stimulus output signal related to timing, amplitude, pulse duration and repetition rate by switches capable of being controlled by said operator, said digital signal being indicative of a selection of at least one of said plurality of sets of stimulus parameters; and control means operatively coupled to said storage means, said converting means and said remote means, said control means for selecting and coupling, based upon said digital signal from said remote means, one of said plurality of sets of stimulus parameters from said storage means to said converting means, for varying the value of at least one of said stimulus parameters of said one of said plurality of sets of stimulus parameters, said selecting; whereby said electrical stimulator can be used to supply trigger information when said electrical stimulator is providing operable muscle stimulation and for parameter value control when said electrical stimulator is providing TENS.