Comparing Pascal and Modula-2 as systems programming languages

The high-level programming languages Pascal [JEN76] and Modula-2 [WIR82] are evaluatedas tools lor system programming. The construction of operating system utilities in Pascal is the focal point of the first part of the paper. Pascal is shown to be adequate for this limited class of applications, on the condition that the program development system provides enough support. The basis of the development system described here is formed by the POST library, a model of Control Data Corporation's Cyber operating system NOS/BE, written in Pascal. Although the class of problems addressed can be solved with Pascal, a language like Modula-2 with features such as separate compilation and low-level programming support is better suited to serve as an operating system implementation language. To illustrate this, some Pascal programming examples were rewritten. The reader is assumed to have a working knowledge of both Pascal and Modula-2