Showing papers on "Software portability published in 1975"

Hints on distributing portable software

Abstract: Would-be implementors of portable software often encounter frustrating difficulties when attempting to enter the distributed text into their computers. This paper summarizes various problems which may arise, and indicates how the distributor can head them off. The conventions used by several successful distributors are given to illustrate possible solutions.

A system for reliable engineering software

Abstract: Much of the software developed to support engineering design calculations is produced by persons whose primary job skill is not that of computer scientist. Software validation techniques suitable for use by these engineer-programmers have been under investigation by the Navy as part of a project designed to increase the reliability, usability, and portability of engineering design software. The results of the project are summarized and a software validation tool is described.

A portable diagnostic facility for SNOBOL4

Abstract: In programming systems based on abstract machine modelling concepts, the underlying structure of the abstract machine can be made available to the software implemented on it. The result is an unusual facility for diagnosis and exploration of software structure. Such a facility has been added to the macro implemention of SNOBOL4. This paper describes the nature of the facility, illustrates its use, and presents some results of using it for language implementation and development.

Interactive graphics on intelligent terminals in a time-sharing environment

Abstract: Interactive graphics in a time-sharing environment should be organized in such a way that the user's activities are locally processed in order to avoid unacceptably long response times -- especially if only low-speed communication links are available. On the other hand, the host computer must be kept informed about the user's actions and, conversely, the display file in the terminal has to be updated whenever the execution of the application program cases a change in the visual representation. In order to avoid the transmission of redundancy, we decompose the display file into two intersecting parts such that the part in the host computer and the other in the terminal contains only the locally required information. The necessary communication between both parts is maintained by an information module generated on the base of a low-low-level intermediate language (L4) and exchanged between computer and terminal. This leads to the notion of an abstract terminal whose "machine language" is L4, facilitating the implementation and portability of graphic programming systems. The L4 concept and our experiences with its implementation is discussed.

Experience with Module-Level Specification Methods

Abstract: During the past three years, SofTech has been developing design and specification methods with the goals of improving design quality, reducing integration problems, increasing software portability, and enhancing project control and estimating methods. In particular we wanted to increase the visibility of the detailed design process in order to facilitate design reviews and design iterations. We also hoped to improve the description and management of all module interfaces in order to reduce integration problems and to allow alternative implementations of a module to be "plug-to-plug" compatible–an important consideration when software systems requiring several man-years to build are designed to be portable.

Usability and portability of a compiler writing system

Abstract: This paper presents a system for automating the production of compilers for programming languages. It emphasizes two particular aspects of this system, its usability and its portability. It also gives a comparison with some good competitive systems, and draws conclusions for future work. The system produces compilers written in the programming language Pascal, from a self-contained description of the language to be compiled. This description uses a notation similar to Backus-Naur form for the syntax, and semantic attributes and actions written in Pascal for the semantics. The system is written entirely in Pascal, and is in current use on several computers.

Writing algorithms in algol 60

Abstract: This paper discusses the difficulties of writing procedures and programs in ALGOL 60 for general use. It also shows how the problems can be alleviated and overcome.

Problems in the design of control procedures for computer networks

Abstract: This paper is one in a series of short papers highlighting research problems in the area of computer communication. Two previous papers have described problems in the design of data communication networks [CHOU 74] and selected research areas in computer communication [KLEI 74a]. In this paper, we will concentrate on problems which arise in the design of control procedures for computer networks. While some of the problems we are going to describe refer explicitly to packet - switched computer communication networks, others apply to packet-switched as well as line-switched systems. We will consider the following six problems:1. Flow control and routing2. Design and implementation of efficient protocols3. Definition of network performance4. Portability of communications software5. Distribution of intelligence6. Process synchronization with unrealiable components

Device independent graphics software: is it possible??

Abstract: Today there is an ever growing need (if not demand) for the development of a graphics software "standard". Compatibility between different elements of the graphics industry has often been the issue of heated debate. Even the idea that any graphics standard would be premature and could stifle future design creativity is a highly argumentative issue. However, let us accept the premise that a graphics standard is to be derived and address the question of what considerations, methods, goals, practical economics and human factorings should be included within the design of an ideally compatible passive/interactive device independent standard.Before hierarchical languages such as EULER-G, LEAP, METAVISU, BCPL, etc. can be evaluated for standardization, a basic set of standard graphic "primitives" must be defined on which further evolutions of graphic applications and languages can be based. These primitives are the basic operators which will define the mode and capabilities of system operation. The "primitive standard" should then be the first issue of attack. Concepts such as extendibility, portability, upward compatibility and device independence must be critically interrogated so as not to limit the role of the primitive standard, or compromise the capabilities of future based software.This paper will not attempt to answer the question it presents, but perhaps will provide some tangible elements with which to better assess the argumentative issues. Conclusions will therefore be left up to the reader. What is presented is a survey and evaluation of past and current techniques (i.e. potential goals, graph theory, system design, and human engineering) as assessed from practical observations and experience, and which lend themselves for consideration within the design of a primitive "standard" system. The conclusion of this paper projects a possible systems concept which has been drawn from techniques presented by several independent sources. Such a concept demonstrates perhaps, one potential answer for the "primitive standards" question.

Selection of Instructional Media Systems.

Abstract: This article describes a systematic method of viewing the important variables which must be considered in selecting a media system for a learning goal. The method looks first at the software in terms of seven variables: degree of control, kind of learned capability, cost, flexibility, population, adaptability and compatibility. Once the software is selected, the reader is led to look at hardware in terms of six variables: type of software, cost, compatibility, portability, life and maintenance cost. In each case all choices are seen in juxtaposition and choices are narrowed down to one or a combination. An example is included as an appendix to the main text.