A description is presented of a new flow-cytometer (FCM) computer system, the EPICS C analyzer, which was developed to be used by a moderately trained technician as opposed to an FCM expert. The system was made robust and user-friendly by the use of menu-based rather than command-driven software. The user primarily interacts with the self-explanatory menus by depressing one of the eight membrane selector switches located on each side of the screen. The minimizing of typing and restriction of the user's responses greatly simplify the use and design of the software. The EPICS C operates in two modes: as a reliable clinical instrument and as a research tool. The instrument settings are stored on disk files rather than manually logged into a book. The settings for the predefined tests are read from the disk.