acm-header
Sign In

Communications of the ACM

Table of Contents


President's letter to the ACM membership


Eliminating monotonous mathematics with FORMAC

The FORMAC (FORmula MAnipulation Compiler) programming system provides a powerful tool for performing mathematical analysis. It is an extension of FORTRAN IV which permits the use of the computer to perform the tedious algebraic …

Mathematical experimentation in time-lag modulation

Equations of the form du/dt = g(u(t), u(h(t))) arise in a number of scientific contexts. The authors point out some interesting properties of the solution of u′(t) = -u(t - 1 - k sin &ohgr;t) + sin at. These properties were obtained …

A general method of systematic interval computation for numerical integration of initial value problems

A procedure is given for continuously computing and monitoring the step size to be used by a self-starting, pth-order numerical integration method to solve an initial value problem. The procedure uses an estimate of the truncation …

Code extension in ASCII

The American Standard Code for Information Interchange (ASCII) contains a number of control characters associated with the principle of code extension, that is, with the representation of information which cannot be directly  …

Rectangular holes in twelve-row punched cards


Description of systems used for data transmission

Task Group X3.3.51 is working to develop proposals for standards relating to the performance of systems used for digital data transmission. It has published two tutorial papers which were submitted by the U.S.A. to the International …

Computer simulation—discussion of the technique and comparison of languages

The purpose of this paper is to present a comparison of some computer simulation languages and of some of the packages by which each is implemented. Some considerations involved in comparing software packages for digital computers …