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Communications of the ACM

Table of Contents


Thoughts on continuous change simulation languages


Böhm and Jacopini's reduction of flow charts


President's letter to the ACM membership


A computer technique for displaying n-dimensional hyperobjects

A digital computer and automatic plotter have been used to generate three-dimensional stereoscopic movies of the three-dimensional parallel and perspective projections of four-dimensional hyperobjects rotating in four-dimensional …

A comment on Galler's letter


Contextual understanding by computers

A further development of a computer program (ELIZA) capable of conversing in natural language is discussed. The importance of context to both human and machine understanding is stressed. It is argued that the adequacy of the 0 …

The AED free storage package

The most fundamental underlying problem in sophisticated software systems involving elaborate, changing data structure is dynamic storage allocation for flexible problem modeling. The Free Storage Package of the AED-1 Compiler …

On compiling algorithms for arithmetic expressions

This paper deals with algorithms concerning arithmetic expressions used in a FORTRAN IV compiler for a HITAC-5020 computer having n accumulators. The algorithms generate an object code which minimizes the frequency of storing …

A comparison of batch processing and instant turnaround

A study of the programming efforts of students in an introductory programming course is presented and the effects of having instant turnaround (a few minutes) as opposed to conventional batch processing with turnaround times …

An efficient machine-independent procedure for garbage collection in various list structures

A method for returning registers to the free list is an essential part of any list processing system. In this paper, past solutions of the recovery problem are reviewed and compared. A new algorithm is presented which offers …

Parsing of decision tables

Reduction in the size of decision tables can be accomplished by several techniques. The techniques considered in this paper are on the parsing of decision tables with regard to horizontal and vertical data structures, job identity …

Algorithm 309: Gamma function with arbitrary precision


Towards standards for handwritten zero and oh: much ado about nothing (and a letter), or a partial dossier on distinguishing between handwritten zero and oh

The Chairman of the ACM Standards Committee, Julien Green, has charged me with making “more effective use of CACM for communication … to get grass-roots opinions from the ACM membership.” This paper is the first attempt. A partial …

ARPA: a visible means of support

The Advanced Research Projects Agency has probably done more to lift computer science from other disciplines and to put it on its own feet than any organization inside or outside of government. Even today, when support of computing …