This paper describes the design and construction of a digital-to-digital interface for a laboratory microcomputer. In this application, signals from a laser-enhanced ionization experiment are processed with a boxcar signal averager which is interfaced to a Commordore PET 4032 microcomputer. Software has been developed for the microcomputer which performs various operations on the data and prints the values for the average analyte signal, average standard signal, analyte-to-standard ratio, average noise, and analyte signal-to-noise ratio. This interface is also applicable to other laboratory instruments with binary-coded decimal outputs.