The FC/ECS project involves designing and implementing computer-based data acquisition, management, and analysis systems for Flow Cytometry applications. Our recent effort has been primarily directed toward high volume sites, which are not adequately supported by commercially available data systems. The Immunology Branch, NCI, is the primary site where prototype hardware and software are installed and tested. During this fiscal year, the two-parameter expansion of the APR data analysis package (developed by CSL for the DLDACS project) has been integrated into our data management and analysis system. Users of this system now have a coherent, flexible means of applying sophisticated data analysis procedures to histogrammed single and dual parameter data.