The rapid pace of advancement of microprocessor technology has shown no sign of diminishing, and this pace is expected to continue in the future. Recent trends in such areas as silicon technology, processor architecture and implementation, system organization, buses, higher levels of integration, self-testing, caches, coprocessors, and fault tolerance are discussed, and expectations for further advances are highlighted. How these trends and expectations will drive the markets and applications, and vice versa, is also explored.

Recent trends in computer architecture have increased the amount of control logic (e.g., microinstructions) in digital systems, thus making testing and debugging a more formidable task. This correspondence discusses the needs and objectives of software simulators for testing and debugging microprogram logic, and discusses a simulator developed to aid the development of a large microprogrammed system.

Because of the tremendous difficulty of producing reliable software (application and system software) and the serious consequences of software errors, a new solution is being explored: the development of a new computer architecture that will substantially enhance the reliability of the programs executing above it. This paper concentrates on the storage concepts (e.g., data representations and addressing) in the architecture.