ISSN:0038-0644    

DOI:10.1002/spe.4380141202

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper describes QS, a program which inputs data in a very general format. QS interprets a script, which contains text to be used to prompt the user, and commands which collect the data from the user. This apparently simple description hides an idea of great power, and in this paper examples are provided of the use of the program in three areas. (1) A system for producing questionnaires and psychiatric interview schedules relies on the program to provide a data validation system which is automatically updated to keep pace with changes to the schedules. (2) The program provides a general purpose patient interviewing package. Most current systems are specific to a particular interview, but new interviews can be administered by QS simply by changing the script, which is much simpler than writing a new program. (3) The program also provides a means of presenting multiple choice self assessment examinations, or programmed instruction to students. Again any set of questions can be set, just by writing a new scriptThe design of the program is discussed with reference to the criteria of simplicity, ease of writing and maximum recycling of existing software. The advantages of the tools approach to software design are stressed.

ISSN:0038-0644    

DOI:10.1002/spe.4380141203

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper describes the design and implementation of a kernel for the distributed programming language StarMod. The distributed programming kernel was written in a subset of StarMod supported by a concurrent programming kernel. Kernel issues addressed include process representation, I/O device management, signal semantics, system utilities, network communication and the implementation of high‐level language communication primitives. We conclude with a summary of our experiences in the development of a ‘bare machine’ kernel for a network of microproce

ISSN:0038-0644    

DOI:10.1002/spe.4380141204

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractAn interactive program inevitably has a need for a user interface which exceeds the simple combination of a write and a read statement. This is necessary to prevent a program abort due to an input error from the side of the user. Also it is desirable to allow for more advanced types of input than single characters or numbers. For these reasons a general‐purpose input package has been developed which allows for sophisticated command‐driven programs while offering the programmer as well as the user an easy‐to‐use interface. The structure of the package is described and examples of its use ar

ISSN:0038-0644    

DOI:10.1002/spe.4380141205

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractProgramming languages which support separate but not independent compilation are prone to a problem called trickle‐down recompilation. These languages, which include Ada, Modula and others as well as Mary2,1permit a compilation unit to refer at compile time to objects declared in another, imported, compilation unit. When the exporting compilation unit is recompiled for any reason, its exported interface may change, and so the importing compilation units which are the clients of that interface must be recompiled. These recompilations in turn force others, and so onMany recompilations are in fact innocuous, in that they may change the run‐time behaviour of the recompiled unit but do not alter the exported interface. This paper describes the implementation of that portion of the Mary2 language system which performs just those recompilations actually necessary and avoids redundant recompilations. The methods described are applicable to the implementation of any other language which enforces version control across compilati

ISSN:0038-0644    

DOI:10.1002/spe.4380141206

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA major problem facing the developers of large pieces of software is source code version control. This paper describes how semantic nets can model this process and how a semantic net processor can be used to construct a flexible and portable source code control system.

ISSN:0038-0644    

DOI:10.1002/spe.4380141207

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractWe discuss a simple algorithm for solving sets of simultaneous equations. The algorithm can solve systems of linear and some kinds of non‐linear equations, although it has nowhere near the power of a general non‐linear equation solver. Its principal advantages over more general algorithms are simplicity and speed. Versions of the algorithm have been used in a graphics language and in a system for interactively modifying the equations that constitute financial models. We discuss the second application in more detail h

ISSN:0038-0644    

DOI:10.1002/spe.4380141208

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe design of a portable, production‐quality dynamic microprogramming system is given. The system is an extension to UNIX; it allows multiple users easily to time‐share the writable control store on a Perkin‐Elmer 3220. Each process may have its own microcode support, known as a microimage; processes may share microimages. Microimages are managed either in an optional software cache in kernel memory or in user memory where they are subject to secondary memory swapping. The physical loading of the WCS is accomplished in on‐demand fashion in the sense that only the first attempt to enter control store during a given scheduling quantum can cause a WCS fault. Users are prevented from erroneously entering control store by separate management of the control store entry points. The paper provides sufficient detail to allow other UNIX and similar systems to adopt this approach. Performance effects of WCS contention add from about 0.5 to 1 per cent overhead to the jobs, and the use of vertical migration has improved job run times up to 50 percent. This system has been in use for over a year and provides the main support for ongoing research into vertical mi

ISSN:0038-0644    

DOI:10.1002/spe.4380141209

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractWSH is a window managing command language interpreter (shell) for the UNIX operating system. This interface increases a user's power to communicate with UNIX by providing a process management environment based on an integrated virtual terminal‐shell design. Unlike conventional shells, WSH affords its user the ability to monitor and communicate with multiple processes within a single display context. Windows represent virtual terminals in the WSH design, and as such are device‐independent abstractions of real terminals. Since the design of the virtual terminal environment is based on UNIX's TERMCAP terminal database facility, WSH is portable across all versions of UNM supporting this feature. WSH requires neither alteration of existing UNIX facilities nor special display devices. The current implementation runs on a Digital VAX 11/780 under Berkeley UNIX 4.1 environm

ISSN:0038-0644    

DOI:10.1002/spe.4380141210

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380141201

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY