Current and anticipated advances in semiconductor technology, in general, and in the area of microcomputers, in particular, will lead to a widespread utilization of distributed computer systems. The advantages of these types of systems have led to numerous design efforts. Most of these efforts have been undertaken in a largely ad hoc manner without any mechanism for the evaluation of design tradeoffs. At the same time it has become apparent that the most desirable evaluation approach must be objective and quantitative in nature. In this document we present a framework by means of which such an evaluation can be undertaken. The elements of the framework are identified and the requirements of each of these elements are given.

Generation of curves using incremental steps along fixed coordinate axes is important in such diverse areas as computer displays, digital plotters, and numerical control. Direct implementation of a nonparametric representation of a curve, f(x, y) = 0, has been shown to be attractive for digital generation. The algorithm in this paper is developed directly from the nonparametric representation of the curve, allows steps to be taken to any point adjacent to the current one, and uses decision variables closely related to an error criterion. Consequently, the algorithm is more general and produces curves closer to the actual curve than do previously reported algorithms.