摘要:

AbstractIn a computing network environment, a user may have access to several different computers, each with its own command language. For the inexperienced user a uniform interface would be a great benefit. Since there is little possibility that a universal command language will ever be developed, we have devised a system in which a microcomputer is used to intercept all messages between the user and the orginal operating system, presenting a consistent interface to the user. This paper describes the design of such a protective interface and gives an account of experience with its use.

ISSN:0038-0644    

DOI:10.1002/spe.4380101202

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe scanner is a subroutine which is frequently called by an application program like a compiler. The primary function of a scanner is to combine characters from the input stream into recognizable units called tokens. A method has been presented in this paper for designing such a scanner, also frequently referred to as a lexical analyser in the current literature. The major steps involved in this design process are: identification of tokens, construction of a state diagram, building driver tables and finally writing a scanning routine. The rules for generating the driver tables are described and an algorithm for the scanner, utilizing these driver tables, is included. The method has been successfully used to build the system scanner for a user oriented plotting language. It is concluded that the method is well defined, gives rise to a modular design and as such easily lends itself to language extensions.

ISSN:0038-0644    

DOI:10.1002/spe.4380101203

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThis paper describes the results of controlled experiments with a Honeywell H6000 series multiprocessor computer system, 212 experiments were performed using 14 test workloads on 8 H6000 configurations. The number of processors varied from 1 to 4, system controller units (SCUs) from 1 to 4, and main memory from 256K to 1024K words. The ratio (P) of I/O time and CPU time for the test workloads varied from 0.01 to 5.07. The improvement in throughput is expressed in terms of relative throughput (φ), defined as the ratio of elapsed time for a given test workload on a single‐processor configuration to that on a multiprocessor configuration. The relative throughput increased monotonically with an increase in the number of processors for test workloads in the range 0

ISSN:0038-0644    

DOI:10.1002/spe.4380101204

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe report describes the main algorithms in a computer program for interfacing a viewdata terminal to arbitrary application computer programs, which were not specially written for this terminal. The interface handles the problems of partitioning the input and output to/from the application to suit the small and non‐scrolling screen of the viewdata termina

ISSN:0038-0644    

DOI:10.1002/spe.4380101205

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractAs a result of experiencing problems with manufacturer's software on the early 2900 machines Edinburgh University took the bold step of attempting to move the general purpose timesharing system EMAS from an ICL 4–75 to an ICL 2970 computer. This paper describes the move together with the changes made and includes some preliminary performance figures from the new system. This implementation project has produced a major time‐sharing virtual memory operating system with a fraction of the effort required to implement the original sys

ISSN:0038-0644    

DOI:10.1002/spe.4380101206

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractPackage programs allow people who are not computer experts to use the power of machine computation for specialized purposes. Because the designers of scientific packages are more often experts in their scientific field than in computing, they may ignore issues of transportability and ease‐of‐use until too late, and produce a package that is difficult to use, and difficult to move to a different computer. In this paper we suggest some techniques to aid the scientific package designer.We suggest a kernel of routines that interface to the peculiar operating system of each machine, providing sophisticated but standard operating system services. This kernel makes the operating system of each computer appear identical and does not pose a difficult implementation problem. Above this interface all code can be machine‐independent, without sacrificing power and ease of use on any machine.We also suggest some novel organizations of processing routines designed to make the system easy to alter and extend. Complete independence of modules encourages centralization of tasks, which is both efficient and essential for easy extension. With this organization, the vast preponderance of package code can be written in machine‐independent ANSI FORTRAN. We suggest the use of a preprocessor like RATFOR to make this more pleasant.The paper closes with an application to an image‐processing package, in which a major problem is the flexible sequencing of processing

ISSN:0038-0644    

DOI:10.1002/spe.4380101207

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThis note describes some interesting results observed during the implementation of Pascal‐P upon a Data General NOVA computer. A significant performance improvement was obtained by altering the program structure of the Pascal‐P compiler to reflect the dynamic behaviour of the program. Some implications of this behaviour for the design of computer architectures are discus

ISSN:0038-0644    

DOI:10.1002/spe.4380101208

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractA case study in rapid prototyping of a new language processor is described. A quick version of the system was developed in SNOBOL4, revised in SNOBOL4, and then rewritten in Pascal. This led to an operational system very early in the development cycle where operational characteristics of the system could be tested easily. The goals of this experiment as well as some of the results are described.

ISSN:0038-0644    

DOI:10.1002/spe.4380101209

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380101201

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY