This paper reports on a multi-year development effort to provide exact simulation of aircraft primary control systems under all conditions of aircraft control and operation for all regimes of flight and environment conditions. The development demonstrated the ability to develop realistic models and provide for their exact solution via digital computation while integrated with a highly responsive control force simulation system. Digital quantization effects are eliminated by very high rates of computation achieved by using dedicated microprocessors within the control loop, resulting in no degradation of control "feel," smoothness, or response. Further improvements in long-term stability, calibration, and measurement are also achieved. The paper discloses the results of various comparative analyses between digital and analog, for various force and position servo loops, leading to the development of a microprocessor-based digital control loading system. Trace comparisons are made between the final breadboarded system versus actual aircraft control measurements for force/displacement and dynamic stick response tests to demonstrate the fidelity achieved by the system.