In a microprocessor project such as the Berkeley Intelligent RAM (IRAM) Project, there needs to be a golden architectural model that is simple, precise, and verifiable. For these reasons, the golden model is written as a computer program so that it can be compared to other models (e.g. RTL or gate-level) in an operational manner. Furthermore, the architectural model is often used for compiler, operating system, and application development, and consequently needs to be very fast. Thus, fast languages such as C++ or even assembly are common choices. In addition to a fast simulation environment, developers need good documentation. In a microprocessor project, the documentation needs to be up-to-date and correct with a high degree of confidence. This paper describes the approach taken in the IRAM project to derive the architectural simulator and architecture manual from a single source. This method disallows many types of inconsistencies between the model and the documentation of the model that can remain undetected in traditional approaches.