摘要:

AbstractTwo algorithms that solve the frequently occurring problem in computer graphics, windowing, are described. The primary distinction between the two algorithms is the need for multiplication and division in one of them. The algorithms are compared for running time and size on two commonly used minicomputer systems, the Digital Equipment Corporation PDP‐9/15 and PDP‐11. Not surprisingly the algorithm incorporating the extended arithmetic capability executes faster and the PDP‐11 versions are substantially sm

ISSN:0038-0644    

DOI:10.1002/spe.4380050202

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractThis paper describes two of the abstract machines used to support the STAB‐1 language, and discusses some problems of implementing the language on two different computers, the DEC PDP‐11 and CTL's Modular‐1, Interpretation of the abstract machine code and direct translation is considered for both comp

ISSN:0038-0644    

DOI:10.1002/spe.4380050203

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractThe advantages (and disadvantages) of on‐line debugging have been discussed extensively in the profession. We propose to couple APL with the debugging process. Techniques for ‘translating’ other languages into APL are presented, and the trade‐off between the cost of this translation process and the benefits to be gained by debugging in APL are discussed in terms of an actual PL/1 programming

ISSN:0038-0644    

DOI:10.1002/spe.4380050204

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractThe design objectives of real‐time operating systems for minicomputers are considered. Simplicity, efficency and avoidance of superfluities are the main criteria. A typical multitasking structure is sketched and the executive elements to support it are analysed. Examples of their use in simple Input/Output are given. Filing systems are then discussed, followed by the interface with the operator. Finally, the problem of linking and loading the modules which make up a simple core‐resident real‐time system is rev

ISSN:0038-0644    

DOI:10.1002/spe.4380050205

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractThe author describes some of his experience gained by working in the area of syntax‐directed compilers and parser generating systems during the past ten years. His most recent work in this area was designing and supervising the implementation of a conversational parser generator which has been operational for about two years. The paper describes this generator, its implementation, usage and the characteristics which make it practical to use. The author's main conclusion is that althouth it is relatively easy to implement nuclei of parser generating systems which are of educational value, the implementation of a practical system requires a major programming effor

ISSN:0038-0644    

DOI:10.1002/spe.4380050206

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractA software measurement tool designed for the users of PRIME, an interactive system being developed, is presented. The tool, called SMT, allows its user to instrument a program, modify a pre‐existing instrumentation and specify how the collected data are to be reduced by typing in a few simple commands. The user can also write his own measurement routines, which specify the actions to be taken at event detection time, and submit them to the SMT; after checking their correctness, the SMT deals with them as with its built‐in, standard measurement routines. The design goals of a general‐purpose tool like the SMT are discussed, and the prototype version of the tool, which has been implemented, is described from the two distinct viewpoints of a user and of a measurement‐tool designer. An example of the application of the prototype to a measurement problem is illustrated, the reasons why not all of the design goals have been achieved in the implementation of the prototype are reviewed, and some of the foreseeable extensions of the SMT are de

ISSN:0038-0644    

DOI:10.1002/spe.4380050207

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractThis paper describes a processor which automatically produces file conversion programs based on non‐procedural user specification. The processor accepts, as input, descriptions of a source file and a desired target file with some auxiliary descriptions of associations between the two. This is specified by a user in a Data Description Language (DDL). To specify validation criteria, complex conversions not built in to the system, security criteria or summary processes, the system also accepts specifications in a Data Manipulation Language (DML). It produces, as an output, a conversion program in PL/1 capable of converting the described source file into the desired target file. The paper describes the structure, system design, capabilities and applications of the DDL/DML language and processor, including an illustrative exampl

ISSN:0038-0644    

DOI:10.1002/spe.4380050208

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

摘要:

AbstractA basic satellite system consists of a minicomputer, with card reader and line printer, emulating the Remote Job Entry (RJE) workstation of a mainframe manufacturer. The addition of a disk stroe increases the range of facilities which can be offered by such a system. Apart from a number of subsidiary advantages, this leads to a system which can interface a community of computer users to its mainframe computing facilities, and hence to a user image which is stable over some long period of time. The paper outlines how an advanced satellite system was simply assembled from four basic components. These components were written in different languages by different institutions, but the use of a standard message passing programming interface provided a sound framework for the detection and elimination of errors.

ISSN:0038-0644    

DOI:10.1002/spe.4380050209

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380050210

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380050211

出版商:John Wiley&Sons, Ltd.    

年代:1975

数据来源: WILEY