https://ir.unisa.ac.za/handle/10500/23876 Tue, 05 May 2026 15:19:09 GMT 2026-05-05T15:19:09Z https://ir.unisa.ac.za/handle/10500/23943 The fixpoint theorem in the El-Calculus Postma, SW; McGee, A The οr.1-calculus is presented as an extension to the standard 1-calculus, and a r.1-term called the strong conditional is discussed. The strong conditional is shown to be non-monotomic, and an extension is made to the r.1-calculus to allow the fixpoints of recursive r.1-abstractions to be established. Mon, 01 Jan 1990 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/23943 1990-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/23942 A review of the use of computers in education in South Africa: Tertiary education Pistorius, MC; Fallick, PM This informal review is based on personal discussions carried out within the last year with various experts in the field on the current use of computers in tertiary education, particularly at universities. An attempt has been made to obtain information on the type of use being made of Computers - here this generally means: ''Which academic departments are involved and what aspects of their teaching are they attempting to use Computer-Assisted Instruction (CAI) for? "Also of importance are the hardware and authoring languages or authoring systems used, and any interesting research or social responsibility programmes in progress. The present economic climate has resulted in any advances in the use of CAI at universities depending largely on sponsorship from private sources. The urgent need for ways of reducing the drop out and failure rate of students in first year, particularly in the Science, Engineering and Medical faculties remains, however. There is a very real economic necessity for improving the productiveness of teaching at universities in Southern Africa. Mon, 01 Jan 1990 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/23942 1990-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/23941 MINIX for a distributed database system Meumann, MD; Rennhackkamp, MH A user of a distributed database management system must be able to access data which is stored on a number of different sites, connected by a network, without being aware of the physical data distribution. The NRDNIX distributed database management system consists of four major components, namely the presentation manager, communication kernel, database manager and network manager. The development of a distributed system requires the addition of communication capabilities to the supporting operating system. The MINIX operating system could be considered as a possible implementation environment. MINIX is based on the client-server message passing model. Architecturally it consists of a user layer, a server layer and two kernel layers. A distributed database implementation using MINIX can be configured as a database server process, an extension to the existing file system, a specialized database file system, a network operating system process or a distributed operating system process. MINIX has a number of drawbacks, namely deadlock, alarm signals, deviations from the message passing model and memory limitations. The severity of the fundamentals design flaws in MINIX render it unusable for the implementation of a distributed database management system. Mon, 01 Jan 1990 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/23941 1990-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/23940 A file server for a multi-transputer UNIX system Hoffman, PK; Smit, G de V The DISTRIX operating system is a multiprocessor UNIX-like distributed operating system. It consists of a number of satellite processors connected to central servers. The system is based on the MINIX operating system, which is in turn based in UNIX Version 7. A remote procedure calling interface is used in conjunction with a system wide, end-to-end communications 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. Mon, 01 Jan 1990 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/23940 1990-01-01T00:00:00Z