Unix is a general-purpose, multi-user, interactive operating system for the larger Digital Equipment Corporation PDP-11 and the Interdata 8/32 computers. It offers a number of features seldom found even in larger operating systems, including i A hierarchical file system incorporating demountable volumes, ii Compatible file, device, and inter-process I/O, iii The ability to initiate asynchronous processes, iv System command language selectable on a per-user basis, v Over 100 subsystems including a dozen languages, vi High degree of portability. This paper discusses the nature and implementation of the file system and of the user command interface. I.

Abstract: This article examines the academic substance of software engineering. It identifies the basic research questions and the methods used to solve them. What is learned during this research constitutes the body of knowledge of software engineering. The article then discusses at length what about software makes its production so difficult and makes software engineering so challenging an intellectual discipline. 1

This taxonomy makes a main distinction between concepts in Programming-in-the-Large and concepts in Programming-in-the-Many. The concepts are orthogonal and well suited to specify and evaluate environments. 1 Introduction In this paper we present a taxonomy for Software Development Environments (SDE). In this context an SDE will simply mean an environment or a collection of tools, which support the development and maintenance of software systems through all of their life-cycle, i.e. from requirements through coding and testing to documentation and user manuals. This covers a wide span of quite different systems ranging from simple tool-kit like systems as UNIX [1] and A Programmer's Workbench [2] to fully integrated systems as DSEE [3] and Mjølner [4]. In this field many different problems are encountered such as configuration management, version control, uniform descriptions, using data bases as the means of integration, problems arising from the distribution of a project on many dif...

This paper describes an implementation of the UNIX(TM) operating system for IBM System/370 computers. In this implementation an underlying Resident Supervisor, adapted from an existing IBM control program, provides machine control and multiprogramming; while a UNIX System Supervisor, adapted from the standard UNIX system kernel, provides the UNIX system environment. This implementation supports multiprocessing, paging, and large-process, virtual address spaces. Terminal handling is done through an outboard terminal processor. This paper describes the software structure, with emphasis on unique aspects of this implementation: multiprocessing and process synchronization, process creation, and outboard terminal handling. Capacity and performance of the UNIX system on large mainframes is also discussed. The first and principle user of the UNIX system for System/370 is the development project for the 5ESS(TM) switching system. This paper also discusses the use of a large mainframe UNIX system for this development. Included in this discussion are the reasons for selecting this system for development, applications software porting, and general experience with mainframe UNIX systems. I.