We discuss the design and efficient implementation of the Rice C Simulation Package (CSIM), a software tool, written in C, and designed to work compatibly with the standard C compiler. The tool provides support for discrete-event or process-interaction simulation, especially for digital logic and queuing theoretic models. We first discuss the existing modeling formalism necessary to abstract a discrete-event model from a real system. We then introduce a set of primitives which are sufficient for preparing an algorithmic specification of the abstract model. Finally, we report on the successful realization of the primitives, discussing or clarifying existing modeling methodology and establishing new methodology when necessary. We also describe the implementation of a recently proposed efficient event list algorithm (the TL algorithm), and present a study of its complexity.