An engine analyzer for an internal combustion engine includes circuitry, under the control of a microprocessor, which senses parameters of operation of the internal combustion engine and supplies digital signals indicative of those sensed parameters. A raster scan cathode ray tube (CRT) display is controlled by the microprocessor to display a simulation of an analog meter having a pointer or needle which moves as a function of the digital signals. When an analog display, such as a tachometer, is selected, the microprocessor controls the raster scan CRT to display a visual depiction of a meter having the appropriate range of values and having a needle which moves according to the measurements made by the system. The microprocessor automatically changes the scale of the simulated meter as appropriate without operator intervention. When operation within a predetermined range of values is required, the microprocessor causes the raster scan CRT display to produce a shaded area representing the range within which the needle should remain.