Dedicated microprocessor systems find increasing applications in automobile instrumentation. Fuel injection systems, digital radio tuners and similar applications employing the microcontroller have become common place. This paper describes a cost effective microcontroller implementation of an automobile instrument cluster by the COPSTM group of National Semiconductor, Santa Clara. The instrument cluster provides a vacuum fluorescent display of the vehicle speed, engine RPM, odometers, battery voltage, engine oil pressure and the fuel level. A modular design involving a single microcontroller in conjunction with peripherals to aid in data acquisition from the transducers allows the quantities to be computed with high accuracies and displayed on a real time basis. The single microcontroller environment places severe restrictions on the availability of RAM and ROM. Coupled with the requirement of real time operation the application poses a non trivial challenge. A non volatile RAM accumulates the mileage covered. Hamming code techniques ensure the integrity of the data contained in the non volatile memory. Inclusion of diagnostics allows a rapid and thorough check against improper operation of the microcontroller, peripherals and the nonvolatile memory. This paper describes the implementation with a COP 444L containing 128 nybbles of RAM and 2K bytes of ROM. A display updation rate of 16 Hz can be comfortably realized.