We describe the design, construction, and operation of a low-cost, microprocessor-based digital correlator. The device has 128 channels, operates in either the single clipping or single scaling mode, and allows selection of the sample interval with 2-digit precision over the range 100 ns to 9.9 s. The device can be operated in the autocorrelate or cross-correlate mode and may easily be expanded to more than 128 correlation channels.