Abstract: In order to introduce data, and in particular charging data, into the memory of a taximeter, the taximeter is connected to an adaptor which is in turn connected to the I/O connector of a local terminal which is connected to a central computer over a telecommunications network. The adaptor includes a microprocessor which is programmed to recognize the nature of the packets of data received from the central computer, to transcode the data, and to transfer the data into the taximeter memory.

Abstract: In the taximeter disclosed, a microprocessor responds to a first set of pulses representing time and a second set of pulses representing distance and receives data representing a tariff from a constant store. The microprocessor calculates fares and advances the fares continuously on the basis of new calculations, while entering the results in a display for the driver and passenger. The constant store is in the form of a non-volatile memory for receiving programming data from an external source through a connector.

Abstract: A taximeter with logic circuitry that provides passenger detection, distance measuring, clock timing, speed referencing, tamper and fault detectors, manual pushbutton controls, settable constants for distance, time and money, and an emergency power supply. Further logic circuitry is provided to count passengers, calculate and add extras, control calibration externally, condition distance pulses, scan tamper and fault detectors, synchronize and debounce manual pushbutton controls, store and input constants, disable the taximeter, enter an external reset code, and internally compare the reset code. Additional logic circuitry may be provided to control the fare charging clock, perform program arithmetic, perform accumulator functions and control logic operations. Also, additional logic circuitry provides an extras charged display, a fare display, rate of charge display panels, recording counters and control of the taxi toplight.