A system for sorting particles is arranged such that the presence or absence of multiple parameters is determined for each particle in a flow of particles, and a logic condition is determined based on the multiple parameters. Thereafter, particles are outputted from the system when the logic condition is present. Accordingly, multiparameter high-speed measurements of a rare subpopulation of particles (e.g. biological cells) can be made amidst a larger population of particles with differing characteristics. When attached to a multiparameter flow cytometer/cell sorter and microcomputer, the system allows multiparameter analysis of cells at rates in excess of 100,000 cells/sec. This system can be an outboard module attached to a commercially available or home-built flow cytometer.