Showing papers by "Brian R. Gaines published in 1974"

Training, Stability and Control.

Abstract: This paper presents a system-theoretic approach to the analysis of the problem of training formally relating it to the control of an abstract dynamic system, the “adaption automaton” of the trainee. The utility of this formulation and the possibility of basing real training strategies upon it are discussed, and it is argued that further constraints upon the automaton are both necessary, and available, in so far as the theory corresponds to practical reality. The minimal constraints generate an extended theory in which training is related to the stability of the adaption automaton. More practical constraints lead to theoretical foundations for strategies of “feedback” or “adaptive” training. Corresponding to each set of constraints a “training theorem” is proved which demonstrates that the constraint is adequate to lead to a simple universal training strategy.

A High-Level Minicomputer.

Abstract: This paper describes the design considerations underlying the development of an advanced minicomputer (.MINIC-S) noW' in commercial production. Emphasis is placed on programming/compiler and operating-sy:stllm requirements ,on the one hand and engineering feasibility on the other. Hicropl:'ogramming/ trapping enables all ~chines of the range to offer the identical architecture and range of facilities. Descriptor-based data organisation enables a very wide range of operand types and lengths to be made available. Relocation/protection and a separate mini~omputer I-O processor enable reaL-time process-structured operating systems to be implemented erficiently. The original design brief for the machine described in this paper was a replacement for an 8-bit mini-computer widely used in machine tool control-the replacement to have enhanced arithmetic. capabilities on wider operands together with wider address scope. The technology was to be conventional and the overall price range to be in the centre of ,the mini-computer market. It very rapidly became apparent, however, in the early stages of design that such a conception of minicomputer architecture had been overtaken by events. On the one hand microcomputers on a few chips were attaining the power 'Of conventional minis-on the other hand standard circuit technology and costs were 1IIuc:h that one could go way beyond present ~nicomputer architec-tures whilst still maintaining the cost objectives. Indeed a basic problem for small computer designers nowadays is the effective exploitation of the capabilities of current electronic components. There is the danger on the one hand of designing a too-simple machine where the processor cost is negligible relative to power-supplies, cabinet and memory, Whereas on the other hand il machine may ha over-engineered with a diverse range of complex facilities that do not integrate well together and are difficult to utilise particularly under compilers. 1.1 Increased hardware content for improved system performance There .Ill'!! two main area.s where inCl'eAsed hardware content may be used to improve system performance and take advantage of recent developments in computer science: (i) Ope~ting systems-the advantages of process-structured operating systems have been extolled as major aids to real-time system development and software reliability [1-3J, both of which are of major importance in typical minicomputer applications. However, the protection and cOlll1lunicat.ion mechaniS1llS necessary are not implementable on conventional machines without a high time overhead which in turn limi t's the potential of process-structuring in its most important applications-most real-time gyste .. are inhel'!!ntly short of time. Additional hardware, appropriately organised. call provide a suitable environment …