An access controller is placed in series with a subscribers telephone set and includes an off hook detector, a ring detector, a central office simulator and DTMF circuitry which cooperate with a microcontroller or microprocessor suitably programmed to select one of a multiple providers of services by generating an access code corresponding to one of the service providers in {HEAD ~ accordance} with {TAIL ~ an algorithm} which provides a desired distribution of usage by the subscriber 
An access controller is placed in series with a subscribers telephone set and includes an off hook detector , a ring detector , a central office simulator and DTMF circuitry which cooperate with a microcontroller or microprocessor suitably programmed to select one of a multiple providers of services by generating an access code corresponding to one of the service providers in { HEAD ~ accordance } with { TAIL ~ an algorithm } which provides a desired distribution of usage by the subscriber
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