Scientific knowledge of the brain and technology of intelligent systems have developed to a point where a computational theory of mind is feasible. This paper briefly describes the RCS (Real-time Control System) reference model architecture that has been used successfully over the past 30 years for designing intelligent systems for a wide variety of applications. It then describes how RCS can be mapped onto the neuronal structure of the brain, and vice versa. Both RCS and the brain are goal-directed and sensory-interactive intelligent control systems. Both are hierarchical in structure and partitioned into behavior generating and sensory processing hierarchies. Both rely heavily on an internal model of the external world for perception and behavior. The world model is used in perception for focusing attention, segmentation, grouping, and classification. It is used in behavior for decision-making, planning, and control. Both RCS and the brain have value judgment processes that assign worth to perceived objects, events, situations, and scenarios; and estimate the cost, risk, and benefit of plans for future behavior. The formal structure of RCS provides a framework for a computational theory of mind that is both quantitative and experimentally testable.