Abstract: A multipoint display or recorder system is based upon a digital processor which controls the sampling of data points and the storage of digital values to be displayed or recorded. A digital display device or recorder (e.g. a colummn of LED's or a dot--printing thermal recorder) is controlled by the stored digital values. The processor is capable of determining independent rates for sampling the data points, refreshing the display and effecting read out to the recorder, each rate being matched to the characteristics of the corresponding peripheral (multiplexing sampler and ADC, display device and recorder). The digital processor enables other functions to be performed, e.g. display of alarm levels for the sampled variables and automatic control of the process giving rise to the variables.