System Operation Process Research Articles

Traffic Service Position System No. 1B: Integration and System Testing

The integration testing and system testing strategies used in the development of the Traffic Service Position System No. 1B (TSPS No. 1B) are described in this article. It discusses novel methods developed for the integration and testing of the first embedded application of the 3B20D Processor and DMERT operating system. The new testing techniques and project management aides, which were vital to the achievement of system quality for the Bell System service, are described. The first TSPS No. 1B went into service on November 20, 1981, in Fresno, California.

The subsystem approach to enhancing small processor operating systems

Operating systems for small processors often do not take full advantage of a small processor's resources. The implementation of a subsystem to enhance the standard operating system has proved to be an effective method to increase the utilization of a small processor's resources. Several different subsystems for small processors are discussed. The advantages of using the subsystem approach in a small processor environment are given.

UNIX Time-Sharing System: A Minicomputer Satellite Processor System

A software support system for a network of minicomputers and microcomputers is described. A powerful time-sharing system on a central computer controls the loading, running, debugging, and dumping of programs in the satellite processors. The fundamental concept involved in supporting these satellite processors is the extension of the central processor operating system to each satellite processor. Software interfaces permit a program in the satellite processor to behave as if it were running in the central processor. Thus, the satellite processor has access to the central processor's I/O devices and file system, yet has no resident operating system. The implementation of this system was considerably simplified by the fact that all processors, central and satellite, belong to the same family of computers (DEC PDP-11 series). We describe some examples of how the SPS is used in various projects at Bell Laboratories.

The subsystem approach to enhancing small processor operating systems

Operating systems for small processors often do not take full advantage of a small processor's resources. The implementation of a subsystem to enhance the standard operating system has proved to be an effective method to increase the utilization of a small processor's resources.

A Parallel Processor Operating System Comparison

Three different operating system strategies for a parallel processor computer system are compared, and the most effective strategy for given job loads is determined. The three strategies compare uniprogramming versus multiprogramming and distributed operating systems versus dedicated processor operating systems. The level of evaluation includes I/O operations, resource allocation, and interprocess communication. The results apply to architectures where jobs may be scheduled to processors on the basis of processor availability, memory availability, and the availability of one other resource used by all jobs.

Architecture of a real time operating system

Architecture is receiving increasing recognition as a major design factor for operating systems development which contributes to the clarity, and modifiability of the completed system. The MOSS Operating System uses an architecture based on hierarchical levels of system functions overlayed dynamically by asynchronous cooperating processes carrying out the system activities. Since efficient operation in a real time environment requires that the number of processes and process switches be kept to a minimum, the MOSS system uses processes only where a truly asynchronous activity is identified. The layers of the MOSS Operating System do not represent a hierarchical structure of virtual machine processes, but rather a hierarchy of functions used to create the processes. This paper describes the layering concepts and process concepts defining the system architecture. It also presents an overview of the specific functions and processes of the MOSS Operating System.

Telecommunications using a front-end minicomputer

The use of a front-end minicomputer to provide varied remote terminal access to a large scale computer is considered. The problems of embedding telecommunications I/O within an operating system are discussed, and it is shown how the decentralization of intelligence acquired by front-end processing vastly simplifies the problem. A specific implementation is discussed with emphasis on the main processor-minicomputer link, the hardware-software implementation, the effect on the main processor operating system, and an assessment of the advantages over a hardwired line controller.