Dynamic characteristics of program execution must be studied in order to calculate meaningful time and parallel processor bounds. The paper entitled "Time and Parallel Processor Bounds for Fortran-Like Loops" [1] studies only the static interaction between statements within a program to arrive at these bounds. Consequently, very loose bounds are obtained for certain programs. Improved estimates of time and processor bounds are provided for two of the example programs presented in the above-mentioned paper. These estimates are based on an expression of the relationship between operations which calculate values and operations which later use those values as operands.

A special purpose computer is described to evaluate the discrete convolution of two sequences of numbers. This computer abandons the traditional model of convolution as a series of inner products which, for input sequences of length n, requires n multipliers and (n − 1) adders to complete a convolution calculation in (2n − 1) time steps. Instead, it is shown that by reorganizing the algorithm, n interconnected processing units are able to evaluate a convolution in n time steps. Each processing unit consists of a multiplier, an adder, and the necessary buffers. In addition to providing increased throughput, the proposed organization results in a highly modular structure with a well defined interconnection pattern.

A computer graphics display system for rapidly shading areas on a raster scan screen is described. With the system, the host computer provides the display controller with the parameters of a set of component trapezoids which cover the area to be shaded. The paper gives an algorithm for use in the host to decompose an arbitrary polygon into component trapezoids and it describes a microcomputer based controller to shade the trapezoids.

This paper describes a simple idea for extending the use of display segment files in computer display systems. The extension is to provide manual control of segment files in a display terminal as well as program control from a host computer. The use of display segments local to the display makes it possible to speed up the rate at which pictures are displayed when the communications line to the host computer is slow or when the host machine is time-shared and heavily loaded. The manual control of segments are terminal functions that work for any program including old programs that knew nothing about display segments.

The design and operation of a simple two-input arbiter module suitable for implementing n-input arbiter trees are given in this correspondence.

This paper describes an algorithm that is suitable for fast implementations of nonrecursive and recursive digital filters. High speed is realized at the expense of memory; however, the memory-speed tradeoff is flexible so that many hardware and software implementations are practical. When memory is not limited, the time required to compute a filter output value is independent of the order of the filter.

This paper considers the stability and errors associated with various combinations of hybrid simulation modes, sampling sequences, and compensating schemes.

A method is presented that combines the multiplexing and A/D function to eliminate analog multiplexing switches.

This paper describes work carried out by the author while working for his Ph.D. degree. The work was done at the University of Arizona, Tucson, under the supervision of Prof. G. Kron, using Arizona Statistical Repetitive analog Computer (ASTRAC II). The ultra-high speed of ASTRAC II permitted the author of obtain Monte Carlo solutions of partial differential equations at a much higher rate than previously reported and to continuously display these solutions.