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The development of a new simulation language, GASP IV, is announced. Who cares? Why should you bother to invest the time to learn the peculiarities of someone else's design? You would rather do it yourself and be certain of the results, or would you? I would like to try to convince you that GASP IV is capable of satisfying your simulation needs by providing the answers to those questions most often asked about this new and powerful simulation language.

The purpose of this article is to describe an experimental senior/graduate-level seminar on "Microprogramming and Emulation" which was offered during the 1974 Spring Semester at the University of Delaware. The stated a priori objective of the course was:"To study the current "state-of-the-art" of microprogramming and microprogrammable machines, to look at where microprogramming is going and why; to develop tools for characterizing tasks and for designing architectures appropriate for a particular task such as emulation."

The process of presenting and reinforcing fundamental concepts and ideas for computer science at the introductory level is impeded by the ever increasing distance between the machine and the student. One very effective way to circumvent the intervening software is to start students on an Ideal Teaching Machine or simulated computers that possess a limited but effective instruction set. A number of ITMs have been designed aimed at various levels of instruction. This paper surveys the major ITMs in use.

Reviews examples of minicomputer software in a number of important application areas, hoping to help the reader make his own judgments about quality and diversity. A brief look at the history of minicomputer software development, and at some current trends in the field may help to put these application examples into focus.

Cornell, like most other large schools, has been struggling with the problem of introductory programming instruction for years. The problem is not yet solved but in the last few years we have done some experimenting and seem to have made some progress. The situation seems worth reporting so that others can perhaps benefit from what has been successful and avoid what has not. The major problems seem to be volume and variety . Pedagogical techniques that are obviously effective with small classes are sometimes impractical when faced with more than a thousand students per year. This may be largely a question of economics, since one could presumably allocate enough resources to the task to have small classes, but this is just not realistic at Cornell and the real question becomes one of finding practical large-scale techniques. For example, the central computing facility at Cornell (a 360/65 under OS/HASP) cannot support a sufficient number of interactive terminals to make that mode of instruction practical. Hence our solution must operate within the constraint of a conventional non-inter-active computer service.

Historically, microprograms have been developed using tools which are appropriate to logic designers (block diagrams, register transfer languages), or systems programmers (microcode assemblers). With the growth of user microprogramming, and the increased demands placed upon computer manufacturers for firmware support, improved tools and techniques have been suggested. In particular, microprogram compilers, i.e., compilers which translate high level source statements into sequences of microprogram control words, have been proposed and implemented. The larger issue to be faced is the nebulous task of supporting the needs of a community which includes:• Manufacturers developing one particular computer (target machine) using microprogramming as a design and implementation technique.• Manufacturers developing a computer system, integrating hardware, operating systems, and programming language support, utilizing microprogramming to tie system functions together.• Users developing their own target machines tailored to applications such as computer graphics, signal processing, or interpretation of higher level languages.• Users or manufacturers who utilize hardware which is microprogrammable to directly solve one or more specific problems, without formally defining a target machine (i.e., simply programming the hardware, or host machine).

The production TSO system at Standard Oil has been running since August 1973. Prior to this date, several limited test systems with small user groups were run, to collect information on modifications necessary to support interactive programming in a manner which would conform to current application development needs and practices. To support program development under O.S. Time Sharing Option, it was necessary to modify IBM supplied code, as well as add code, to the system. The experiments which led to the definition of the modifications needed included a six-month long test system to support a single, small group of application programmers. At the conclusion of this test, the programming group involved estimated an increase in productivity (groupwide) of twenty to thirty-five percent.

s from the meeting are presented herein. Full proceedings will be available from ACM Headquarters in early 1974.

This paper presents a resume of some of the issues involved in adopting computer methods in an area of study not normally associated with quantitative techniques. The topics discussed are: a. the nature of architectural studies, architectural students and computer studies at one school of architecture; b. some computer methods currently implemented in design project work; c. the advantages of computer aided studies for design education.

An interactive test bed for programs written in the system development language CLSD is described. It consists of a compiler and an interactive interpreter. The test facilities and the internal design of the test and bed are described in detail. Experience has demonstrated this to be a very valuable tool in program development.

CAPS (Computer Aided Project Study) is a computer based system which has been developed to assist engineers and designers engaged in aircraft project studies. It has a modular organization encompassing a wide range of topics including mass, aerodynamics, performance and cost estimation. The data flow and module execution is controlled by the PROTRAN system which has been specially developed for CAPS but has other potential applications. Jobs are specified in simple statements using the PROTRAN language. People without programming knowledge rapidly become proficient in its use, but Fortran programmers can use all their experience since it is an extension of that language. This paper describes the development of CAPS and is illustrated by some practical examples. The main features of the PROTRAN system are also presented.

The discussion centered on the needs of engineering students in the field of computer science. It was generally agreed that their curriculum should include an introduction to a higher level language such as Fortran taught with an algorithmetic approach, and an introduction to numerical methods with emphasis on proper use of subroutines. It was strongly recommended by the group that simulation and mathematical modeling, statistics, and analog computation be included. Many felt that some basic concepts of an assembler language as related to mini-computers was important. The group was unanimous in the opinion that computer science subject matter should be taught by those trained in the field, but in all cases the courses should be structured so as to be user oriented. It was strongly recommended that CoED form a committee to study this need and make recommendations to the engineering and computer science educators.

The May/June 1972 issue of COMPUTER was devoted to the subject of design automation. As with other technologies, the ensuing 18 months have provided ample opportunity for change — enough, in fact, to justify a sequel. Below, guest editor Art Collmeyer introduces this month's issue, which presents a collection of papers providing further insight into the construction and application of design automation systems.

The last 10 to 15 years have seen the evolution of hardware diagnosis and testing from an art to a science (see Chang).1 Well conceived and well documented hardware test strategies are now available, as well as reliability measures for hardware designs. Software testing, on the other hand, has not experienced the same growth. (This is not to say that software is not being tested; many complex software systems are up and running without significant problems.) However, unlike hardware diagnosis, software testing methodology is very primitive.

In the Spring 1973 of the Journal, Mr. Petito presented two closely related lectures in note form on the development of manuals, as given at an AMA seminar. The present paper develops computer software documentation with reference to types of documentation, documentation library, and documentation standards.

(1974). Computed Assisted Instruction: Program Development and Implementation. The Journal of Data Education: Vol. 15, No. 1, pp. 18-22.

Almost every academic discipline has some potential applicability to any other field of endeavor we might consider. However, there are three disciplines that share the distinction that they are widely applied in virtually every field of human endeavor. In order of seniority, there are: Mathematics, Statistics and Computing Science . We wish to consider the problems that this situation creates with respect to how these subjects should be taught to a wide selection of students and how a curriculum can be constructed to appeal to a diversity of backgrounds and needs .

The motivation behind this work has been the view that for 20 years computer hardware has become increasingly complex, languages more devious, and operating systems less efficient. Now, microcomputers afford some of us the opportunity to return to simpler systems. Inexpensive, LSI microcomputers could open up vast new markets. Unfortunately, development of these markets may be delayed by undue emphasis on performance levels which prohibit minimum cost. We are already promised more complex next-generation microcomputers before the initial ones have been widely applied. This paper discusses these points and describes a simplified microcomputer architecture that offers maximum flexibility at minimum cost. Design philosophy, programming considerations, and typical systems are also discussed. Experience with breadboard versions of this architecture has verified its usefulness over a surprisingly wide range of potential applications.

The Automatic Intercept System Operational Programs provide the logic for processing calls served by the system. These programs also perform administrative and software correction and recovery functions. Described are program organization, use of temporary memory, and details of call processing.

Increased man-machine communications capability can provide improvements in problem solving. This improvement can be achieved by designing flexibility of input and output through the use of interactive graphics. This paper outlines an interactive simulation system for use in city planning. In this system, simulation models of a city's demography, employment, transportation, utilities, and communications systems are interfaced with each other and with a graphics screen through the use of a module called the interface control program. This program functions as a system monitor and recognizes what, where, and when information should be transferred through the system. The interactive city planning model allows applications-oriented problem solvers to effectively use the problem solving capability of the computer to respond to events as they develop during a simulation run.

Computer assisted instruction (CAI) has not impacted the educational world with the degree of success which early proponents predicted. Although CAI has proven to be a more efficient learning tool than common traditional methods in specific instances, the overall success of such systems has been sporadic. There is no question that a well-designed and correctly implemented CAI system can be highly effective; however, several important factors must be overcome to guarantee a reasonable amount of success. These are:• Overcoming the present high cost of hardware while still providing a reliable system having acceptable display capability.• Developing a software real-time operating system which guarantees fast response times.• Authoring high quality courseware.

The case statement is one of the newest and one of the least known of the ‘standard’ control structures in higher level languages. Its importance has increased with the greater use of structured and goto-less programming. This paper surveys the development of the case statement and provides two extensions which are natural and intuitive and which, it is claimed, increase the intellectual manageability of the host language.

Computer science is a field of study in which the experimental and pragmatic aspects, while initially slighted in some curricula, are becoming recognized as playing an increasingly important role. This trend has undoubtedly been hastened by the reductions in hardware costs seen in recent years. As a result, a great many computer science departments in schools across the country are beginning to examine their own needs for computing facilities and other resources not likely to be available from a school's production computing facility.

The diversity of earmold specifications and nomenclature used by the manufacturers often makes it confusing and difficult to obtain an earmold with the characteristics necessary for the amplifying system. Eight earmold manufacturers were surveyed to determine whether or not they were in compliance with standard nomenclature proposed by the National Association of Earmold Manufacturers in 1970. The results show that the manufacturers do not appear to be following the NAEL proposal. A recommendation for the possible solution of the problem is presented.

New software development methodologies such as top-down development, structured programming, and modular design have obvious and reported benefits in improving software quality and reducing software development costs. Since computer simulation languages are themselves software languages, and since credibility and modifiability are never more stressed than in models, the application of these methodologies to simulation languages seems appropriate.The three development methods, top-down development, structured programming, and process construction are considered in their application to computer simulation for program design analysis. While, potentially, each is shown to have significant positive effect in the quality of model product, some also lead to negative effects when used improperly; to implement a new development method which enhances model quality at the cost of model representation can severely degrade the credibility of results. The positive benefits of product quality must be weighed against the negative effects of noncredible results when these techniques are considered for computer system simulation.By accurately representing the system to be investigated in simulation language terms, assurance of the accuracy of results is maintained. If the process of accurate representation were considered as a development methodology itself, then model quality both as a software product and as an analysis tool is possible by supplementing new development techniques with representative modelling.The combination of these two techniques takes us one step further "towards a more mature discipline" as discussed by D. J. Lasser in (15) in that we are using structured translation techniques from real-system to model, validating models directly against the real-system, and increasing mutual understanding between the modeller and model customer via a representative model.Therefore, each of top-down development, structured programming, and process construction are first discussed as they are applicable to general software systems; second, as they are applicable to computer simulation models; and, lastly, how they can be used in conjunction with a representative modelling methodology to enhance both model quality and modelling results.

This paper and the following three describe computer systems to store, retrieve, and manipulate information. These have all utilized time-shared computer systems. All have evolved toward a system constructed of modular component parts and having a high degree of user interaction. Considerable attention has been given to implementation in a form suitable for simple transfer to systems of adequate capability with minimal programming effort. The data bases involved are all hierarchical in organization. The major parts are a language facility, a data base manager, a processing package, and numerous coordinated administration functions. The parts are currently assembled into a package which can be applied to an arbitrary hierarchically structured data base with little user effort. The component parts are also available for integration into more tailored systems for special applications.

There are two approaches to the software reliability. In one approach, software is evaluated in the same measure as hardware by expanding the concepts of hardware reliability. In the other approach, a new measure based on the characteristic concepts of software is introduced. This paper discusses the latter approach and deals with such important problems as reliability prediction and designing.

Many of the problems in the implementation and maintenance of computer programs occur during the transition from detailed functional specifications to reliable computer code (i.e., in the detailed design, coding, testing, and integration of the computer program). A study for the U.S. Air Force found that approximately 65 percent of the software effort in several large systems went into these transitional activities.(1) In other words, about twice as much software effort went into getting the computer programs to work reliably as went into determining what functions the programs should perform. This paper describes a tool to improve that ratio. The Urban Mass Transportation Administration (UMTA) is employing a highly systematic approach to the management of computer software development. Part of this approach is the documentation and review of detailed technical specifications for computer programs. This review helps assure that the computer programs, when implemented, will do the job they are intended to do. The review takes place prior to any coding of the computer programs to reduce the amount of redesign and recoding during programming.

To anyone who has had the slightest connection with the design and construction of large programs for digital computers, it is obvious that this is no trivial task. Many times the design of such programs is woefully inadequate, and the effort required to get them right is tremendous. The sometimes ruinous cost of such inadequate design is well-known.

Scientific computer systems are defined as those which have an information content, which is primarily scientific, and which are designed to communicate scientific results. Such systems have many diilerences from data processing systems and therefore require different methods of analysis. The nature of scientific data files is considered, and a threefold classification system based on file size, system life-time, and computational requirements is proposed. An example of each type of system is given. A series of headings is given to guide an analyst in his approach to a scientific system. In addition, some guidelines are presented for the difficult process of cost-estimating scientific systems.

Even though minicomputers are widely used in industry they are slow to gain acceptance in computer science education. However, because of its increasingly great impact on industry and its potential as a teaching device, the minicomputer should be considered a part of the computer science curriculum. This paper proposes a minicomputer laboratory course at the lower division level emphasizing hands-on use, fundamental computer concepts in conjunction with "computer lore", and problems peculiar to machines. Also, an upper division course is suggested which emphasizes demonstration of advanced programming techniques.

The magnitude of the task of courseware development in the TICCIT project has required the development of well-defined and manageable techniques for courseware preparation. This paper reviews the problems involved and the team production techniques developed to overcome them.

Formal education in computer architecture rests upon the integration of numerous specialized courses. One such course, a new laboratory concerning contemporary, register-transfer level digital design, is described. Design in the course proceeds at the level of interconnection of memories, arithmetic logic units, I/O interfaces, and buses, rather than at the individual gate level associated with traditional combinational and sequential logic design. The principle items of hardware used in the laboratory are DEC Register Transfer Modules, the DEC PDP/16M, and the INTEL SIM8-01 Microcomputer. Numerous software packages have been developed to support activities within the lab including an RTM simulator, a graphical simulation of an RTM control sequencer, a PDP/16M assembler, a microcode generator, and SIM8-01 utility routine, assembler, and simulator. During one fourteen-week term, students are expected to complete six assigned lab projects and one special project. Examples of projects are described. A critique based upon the students' reactions and the technician's experience with the equipment is given together with proposals for future additions to the course.

Since CAI was introduced, the course author has been faced with a new problem. Not only must he have a thorough knowledge of the subject content and the student objectives for the course but he must also learn an instructional programming language. This paper discusses the various types of easy author entry systems that have been developed, describing the salient features of particular systems, and suggests where each type might be used. It also describes a prototype system whose design aims have concentrated particularly on the problems of ease of use, documentation and standardization.

In microprogrammable systems a special type of interpretive linkage mechanism is used. This linkage mechanism, among all known interpretive techniques, shows the clearest distinction between linkage implementation and the execution mechanisms of semantics. The essentials of interpretation by micro programs may be used as part of a design guideline for the design of a variety of multi processor systems or multi micro processor systems, aiming hereby at more clearly structured design solutions. After a short discussion of the interpretive mechanisms, known from microprogrammable systems, its possible impact on the design philosophies for hardware design in computer architecture, and for integrated hardware/software design efforts, is the subject of this paper. Especially one particular design philosophy, derived from the interpretive mechanism of microprogrammable systems, is discussed, which results in computer architectures in form of a hierarchy of interpretive modules. A few examples are mentioned.

A minicomputer installation dedicated to c.a.d. is described. The economy and flexibility of such systems when incorporating comprehensive graphics facilities is stressed. Suitable operating systems are discussed, including an executive program to provide software simulation of three virtual computers (each virtual machine may then run under an independent operating system). Features of the graphical system software are outlined, including device and machine independence, flexibility, ease of use and economy. The applications programming philosophy required is described together with several interactive programs developed for use in electronics design. These programs, used by electronic engineers and research scientists over the past four years, illustrate the flexibility inherent in the system.

After a survey of the design process to underline the different stages in which the use of a computer can be utilized with profit, some programs developed to assist the mechanical designers in their job are discussed. These are organized into an integrated system made up of a supervisor (MLINK), two basic languages (MEDES and TEADI), and several post-processors which are briefly described. Further improvements of the system are also discussed concerning new programs to be developed and new types of hardware to be adopted.

This article gives direct comparisons of various computer types—their costs and capabilities for school use. The authors discuss flexibilities, advantages, and disadvan tages of an assortment of computer hardware.