This paper provides an overview of a prototype simulation-centered intelligent computer-based training (CBT) system--implemented using expert system technology--which provides: (1) an environment in which trainees can learn and practice complex skills; (2) a computer-based coach or mentor to critique performance, suggest improvements, and provide a role model; and (3) a help facility accessible from within the simulation to teach concepts and prescriptions using traditional CBT to deliver content and evaluate mastery. The first section describes the system, which was written in Turbo Prolog and runs on IBM PC compatible computers, noting that it incorporates two databases--one to capture the expert performance information required by the "coach," and the other for the simulation itself. A description of a user interaction with the system is then given which highlights the use of the program's "situation" and "response" windows and its menu system. It is noted that while the prototype demonstrated the feasibility and utility of this approach to interactive computer simulations, it also underscored the difficulties involved in accessing the kinds of rules required to structure knowledge bases in most fields and in working with two interacting knowledge bases rather than one. Future steps which are noted include measures to address these difficulties and to develop a graphics-based user interface. Diagrams of a sample help menu and of situation and response windows are provided. (GL)