A multiway arbiter may be constructed from an interconnected structure of inverting gates which is a generalisation of the bistable flip-flop. Features of the dynamic behaviour of such a 'multi-flop' are illustrated by analysis and simulation based on a very simple nonlinear dynamic model of each gate. Limitations of such a component as an arbiter are explained.

This paper introduces the data oriented requirements implementation scheme (DORIS) design strategy and the data interaction architecture demonstrator (DIADEM), by describing their use for a multiple-robot workspace simulation. The design process, the hardware and the software for the DIADEM are outlined, followed by a discussion of the design used for the simulation.>

The paper surveys the chaotic behaviour of digital filter overflow oscillations. The behaviour patterns of 1st, 2nd and 3rd order filters are described and the available stochastic characteristics of oscillations with chaotic features are illustrated by means of probability density functions and power density spectra for a range of filter parameters and initial states. The analysis and simulation results provide a basis for the design of digital systems which generate signals with a variety of prescribed characteristics. Typical examples are included.>

A recently proposed analogy between discrete systems and flowcharts is discussed. It is pointed out that the analog of Kirchhoff's voltage law does not apply to flowcharts, and that the analogy is likely to be of limited value as an aid to program analysis.

A modification of a discrete-time method of synchronizing the clock frequencies in a digital communications network which makes the system frequency independent of time-varying transmission delays in the links of the network is discussed.

Effects of clock drift on the performance of a discretetime control system for synchronizing all the clocks in a digital communications network are shown by a detailed analysis of the dynamic behavior of the simple case of a two-node network. With a unidirectional frequency drift of one or both oscillators, it is shown that the buffer stores eventually overflow. A more general linear control scheme is also discussed.

A proof is given of a method proposed by Lackey and Meltzer [2] for determining the selection of Rademacher functions that must be combined to generate a specified Walsh function. The method provides a convenient way of digitally controlling a Walsh function generator.

This paper derives and discusses statistical properties (probability density function, moments, power spectrum, and autocorrelation function) of waveforms obtained by nonrecursive digital filtering of pseudorandom linear binary sequences. This filtering may be achieved in practice by forming a weighted summation of binary digits passing along a shift register.