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Communications of the ACM

Table of Contents

President's Letter

ACM Forum: letters

From Washington

The American Association for the Advancement of Science (AAAS) has recently passed a resolution opposing “continuing governmental efforts to restrict the communication or publication of unclassified research.” This statement  …

Programming pearls: algorithm design techniques

The space shuttle primary computer system

Development and application of NASA's first standard spacecraft computer

To provide the autonomy needed by low, earth-orbiting satellites, NASA's first standard on-board processor requires changing only interfacing hardware from mission to mission.

Design, development, integration: space shuttle primary flight software system

The development of Space Shuttle software posed unique requirements above and beyond raw size (30 times larger than Saturn V software), complexity, and criticality.

Architecture of the space shuttle primary avionics software system

PASS, perhaps the most complex flight computer program ever developed, epitomizes the benefits to be gained by establishing a well-structured system architecture at the front end of the development process

A software design method for real-time systems

DARTS—a design method for real-time systems—leads to a highly structured modular system with well-defined interfaces and reduced coupling between tasks.

Hardware protection against software piracy

A system that prevents illicit duplication of proprietary software is suggested. It entails the customization of the programs for each computer by encryption. The use of a public key cryptogram for this purpose means that anyone …