Browsing by Author "Smit, G de V"

Now showing 1 - 4 of 4
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    A control and sequencing language
    (1991) Fair, Colin A; Smit, G de V
    In a process control environment, hatch processes, as opposed to continuous processes, are characterised by multi-product manufacturing lines which often involve frequent product changes. One component of batch control systems is a programming language which is used to control and synchronise the operations of the plant. Initially low-level languages (e.g. ladder logic, boolean algebra and assembly language) were used, but have now been replaced by specialised high-level languages. These languages provide more functionality and are easier to use. The dissertation examines one such high-level sequencing language (CASL) and identifies functionality, clarity and readability improvements that can be made to the language. An implementation of an upwardly compatible compiler for the improved language is described briefly.
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    DistriX : an implementation of UNIX on transputers
    (1989) McCullagh, Paul J; Smit, G de V
    Two technologies, distributed operating systems and UNIX are very relevant in computing today. Many distributed systems have been produced and many are under development. To a large extent, distributed systems are considered to be the only way to solve the computing needs of the future. UNIX, on the other hand, is becoming widely recognized as the industry standard for operating systems. The transputer, unlike. UNIX and distributed systems is a relatively new innovation. The transputer is a concurrent processing machine based on mathematical principles. Increasingly, the transputer is being used to solve a wide range of problems of a parallel nature. This thesis combines these three aspects in creating a distributed implementation of UNIX on a network of transputers. The design is based on the satellite model. In this model a central controlling processor is surrounded by worker processors, called satellites, in a master/ slave relationship.
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    A file server for the DistriX prototype : a multitransputer UNIX system
    (1989) Hoffman, P Kuyper; Smit, G de V
    The DISTRIX operating system is a multiprocessor distributed operating system based on UNIX. It consists of a number of satellite processors connected to central servers. The system is derived from the MINIX operating system, compatible with UNIX Version 7. A remote procedure call interface is used in conjunction with a system wide, end-to-end communication protocol that connects satellite processors to the central servers. A cached file server provides access to all files and devices at the UNIX system call level. The design of the file server is discussed in depth and the performance evaluated. Additional information is given about the software and hardware used during the development of the project. The MINIX operating system has proved to be a good choice as the software base, but certain features have proved to be poorer. The Inmos transputer emerges as a processor with many useful features that eased the implementation.
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    Rita+ : an SGML based document processing system
    (1993) Zsilavecz, Guido; Smit, G de V
    Rita+ is a structured syntax directed document processing system, which allows users to edit documents interactively, and display these documents in a manner determined by the user. The system is SGML (Standard Generalized Markup Language) based in that it reads and saves files as SGML marked up documents, and uses SGML document type definitions as templates for document creation. The display or layout of the document is determined by the Rita Semantic Definition Language (RSDL). With RSDL it is possible to assign semantic actions quickly to an SGML file. Semantic definitions also allows users to export documents to serve as input for powerful batch formatters. Each semantic definition file is associated with a specific document type definition. The Rita+ Editor uses the SGML document type definition to allow the user to create structurally correct documents, and allows the user to create these in an almost arbitrary manner. The Editor displays the user document together with the associated document structure in a different window. Documents are created by selecting document elements displayed in a dynamic menu. This menu changes according to the current position in the document structure. As it is possible to have documents which are incomplete in the sense that required document elements are missing, Rita+ will indicate which document elements are required to complete the document with a minimum number of insertions, by highlighting the required elements in the dynamic menu. The Rita+ system is build on top of an existing system, to which SGML and RSDL support, as well as incomplete document support and menu marking, has been added.