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Advanced cryptographic techniques for computer
Cryptographic techniques which can be used to maintain the confidentiality of information processed by computers are dealt with. Special emphasis is paid to the unique characteristics of computer files that make many cryptographic methods of little use. Relative security, costs, and preferred methods are included in this paper.
Numerical analysis in a Ph.D. computer science program
Numerical Analysis is the study of methods and procedures used to obtain“approximate solutions” to mathematical problems. Much of the emphasis is on scientific calculation. The difficulties of education in such a broad area center around the question of background and emphasis. The Numerical Analysis program in the Computer Science Department should emphasize an awareness of the problems of computer implementation and experimental procedures. Nevertheless, there is a need for a solid background in applied mathematics.
Performance monitoring in a time-sharing system
A software measurement facility which is part of a general purpose time-sharing system is described. The Data Collection Facility (DCF) has been implemented in the Michigan Terminal System (MTS) for the System/360 model 67. It exists for the purpose of monitoring operating system and user program behavior and performance. The overall structure of MTS is outlined in order to explain the implementation of the DCF. Events in the system are identified and recorded from within the supervisor, and dumped to magnetic tape by an auxiliary program for off-line processing. Events in user programs which are unrelated to system actions are recorded with a supervisor call. The time of occurrence of each event is accurately recorded, and data items are further identified by job and type. The overhead associated with data collection and its interference with normal jobs is carefully analyzed, and both are shown to be minimal. Several examples are given of information obtained with the facility and of applications in which it has been useful. Some general guidelines are offered for the construction of future monitoring programs.
The IITRAN programming language
The IITRAN language, developed to be used by students, and its important features are described. IITRAN is a procedure-oriented language with a one-level block structure and a variety of data types. Several novel and powerful features are included. A discussion of design principles to be followed in a student language is given.
A modular computer sharing systems
An alternative approach to the design and organization of a general purpose interactive multiterminal computing system is presented. The system organization described is a conceptually simple arrangement of a bank of interchangeable computers, each of which is a memory/proputor pair, that are assigned to process terminal jobs as they arrive. One of the computers serves as the master or control computer and supervises the collection and distribution of messages from and to the remote terminals. In the simplest form there is a disk drive for each connected terminal. A crosspoint switching network allows any such disk drive to be connected to any computer in the bank, under control of the control computer. Thus, while each active terminal user “occupies” a dedicated disk drive, he may share the computer with many other terminal users in a simple manner. The ratio of users to computers is dependent on both the size and power of the machines used and the computation requirements of the particular mix of users.
This system organization is inherently a simpler and therefore more reliable approach to time-sharing computers and has the potential of a highly available system at relatively low cost. Economic configurations are possible for a range of systems sizes that span at least one order of magnitude. Finally, problem programs developed by remote terminal users can be run on a dedicated batch system if compatible computers are used.
Loader standardization for overlay programs
The overlay capability is described for four of the third generation computer systems: CDC-6000, GE-635, IBM-360, and UNIVAC-1108. A critique of the first three sytems is based on actual experience with a large overlaid trajectory simulation program; a short history and description of this program is presented. A standardization of minimum capabilities for loaders is recommended so that programs which must operate under more than one computer system may be easily converted and maintained. A proposal that overlay software incorporates a memory occupation specification concept instead of the conventional tree structure is delineated. This concept provides more efficient and cost-effective utilization of the memory as well as increasd flexibility in program structure.
Computing capabilities at Argentine and Chilean universities
The author reports on a trip to universities in Argentina and Chile during November 1968, describing university conditions and computing activities. As elsewhere, these universities are experiencing student discontent with the status quo and the solutions they are attempting contrast: Argentina is excluding students from participating in university government; Chile is allowing such participation. University computing service and academic activities are limited. The number of computers is small and so is the capacity, none larger than an IBM 360/40; with some exception, computing science academic programs are rare. This situation is by no means attributable to those responsible for computing developments, who strive for excellence; rather the “system” is hard to overcome. Universities, especially those with strong European traditions, adapt slowly to new academic resources and disciplines; superimposed are the severe technological and economic constraints of the developing nation. Consequently, in the absence of conscious government emphasis on strengthening computing capabilities, future progress may be retarded.
Introducing computing to smaller colleges and universities—a progress report
By technical means that are now routine, computer service for smaller colleges and universities can be provided by remote terminals of a central facility. Access, however, is not enough—effective organizational and educational methodology for introducing computing at such institutions must also be developed. The experience of two years with a statewide network involving 41 institutions is discussed. Lessons include the importance of a separate organization representing the small colleges, the necessity for on-campus training for the institutions, the need for some special programming and documentation to support such users, and the development of curriculum by evolutionary means.
Clarification of Fortran standards—initial progress
In 1966, after four years of effort, FORTRAN became the first programming language standardized in the United States. Since that intital achievement, study and application of the standard specifications have revealed the need for maintenance of the standards. As the result of work intiated in 1967, as initial set of clarifying interpretations has been prepared. The nature of the maintenance, corrections to the standard specifications, and completed interpretations are reported.
An automatic grading scheme for simple programming exercises
A discussion is given of alterations that were made to a typical university operating system to record the results of programming exercises in three different languages, includeing assembly language. In this computer-controlled grading scheme provision is made for testing with programmer-supplied data and for final runs with system-supplied data. Exercises run under the scheme may be mixed with other programs, and no special recognition of exercises by the operators is necessary.
Data communications control procedures for the USA standard code for information interchange
This proposed American Standard has been accepted for publication by USA Standards Committee X3, Computers and Information Processing. In order that the final version of the proposed standard reflect the largest public consensus, X3 authorized publication of this document to elicit comment and general public reaction, with the understanding that such a working document is an intermediate result in the standardization process and is subject to change, modification, or withdrawal in part or in whole. Comments should be addressed to the X3 Secretary, Business Equipment Manufacturers Association, 235 East 42 Street, New York, NY 10017.—E. L.
Information science in a Ph.D. computer science program
This report contains recommendations on a sample course curriculum in the general area of information organization and information system design in a Ph.D. Computer Science Program. The subject area is first briefly described, followed by a listing of some desirable graduate-level courses. Suitable bibliographies are appended.
Some criteria for time-sharing system performance
Time-sharing systems, as defined in this article, are those multiaccess systems which permit a terminal user to utilize essentially the full resources of the system while sharing its time with other terminal users. It is each terminal user's ability to utilize the full resources of the system that makes quantitative evaluation of time-sharing systems particularly difficult. Six criteria are described which have been successfully used to perform first-level quantitative time-sharing system performance evaluation.
The role of programming in a Ph.D. computer science program
In this general paper the role of programming in advanced graduate training is discussed. Subject matter related to programming as well as programming per se is considered. The importance and application of formalism are considered and also the need for good empirical experimentation. A brief outline for a sequence of courses is included, and subject headings that have been obtained from an extensive bibliography are given. A bibliography of programming references is included.
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