Abstract Three kinds of documentation are examined: summary documentation describes the intent and nature of the program; detail documentation gives all the information the user needs to put the program to work; intraprogram documentation is information written into the program to inform the user or programmer. The need for intraprogram documentation occurs at four different times: in the initial design period; during debugging; as the program and system evolve; when it is necessary to adapt the program to other systems There are several means for providing intraprogram documentation. There are comments which can be placed in the header, on each line, at the beginning and end of a subroutine. Also noted is the important use of space for making the comments easier to read and for separating chunks of the program. Special symbols serve the same purpose. Examples are provided to bring home these points.

Goal and Result: The author states that the aim of this book is "1) to present an introduction to computers and programming using the System/370 as the primary vehicle; and 2) to present an introduction o the System/370 for people experienced in computer science. I have found that this book contains a lot of useful information and, in fact, I can say that I learned quite a bit from the book. However, this does not mean that the author has met his goals. As for the beginner, hewould not come out with a thorough understanding of S/370 or computers in general because so little space was devoted to his initiation. The intermediate or advanced computer scientist would learn much about S/370 but I am afraid he would be left with many questions about the beast, just as I was.

The purpose of this paper is to explore the effect of multiple modules of memory together with multiple bus lines for providing effective communication between memory and processors or channel controllers. Apparently the study was undertaken to determine an optimum configuration of equipment for an installation to be made by a computer manufacturer to a university. It suffers from the necessary evil which abides in studying a particular system under specific limitations applying to that system. The author has made no attempt to generalize his results regarding priority and processor performance as effected by the number of modules and buses available. The special restrictions which apply are in terms of channel controller timing and drum unit datum acquisition.

Ivan Flores; Note on a machine algorithm for conversion from reflected binary to natural binary, The Computer Journal, Volume 7, Issue 2, 1 January 1964, P

Compuler Design Con.~dlanL, Norwalk, ConnecKcut Abstracl.The limiting effect of the number of banks of memory upon the response of the computer is studied.It is shown t, hat this effect is diminished and almost removed by increasing the number of memory banks.A quantitative equation relating a wait.~ng-timefactor, 5, to the memory cycle time, the i~put/output time and worst-ease calculation ~,ime for different numbers of banks of memory is derived.This derivation is based upon a number of simplifying assumptions, all of vd~ieh are explai~ed and justified.Two graphs convey these relations and provide a means for estimating an effective number of banks for a given computationM abilit, y.

The purpose of this paper is to describe and discuss the methods available for sorting information within a computer using its internal memory.Considerable detail is obtained by analyzing sorting with logical flow diagrams.These flow diagrams break down the steps required to do the sorting into a number o:f fundamental types and show the sequences and relations among the steps.From the flow diagrams one can prepare programs for most of the presently available computers.The report is divided into three parts.Part A describes each kind of internal sort and illustrates the discussion with appropriate flow charts.Part B derives time formulae for these sorting processes.Part C compares and contrasts the kinds of sorting. PART A. DESCRIPTION AND FLOW CHARTS OF METHODS FOR INTERNAL SORTING *

For each item to be sorted by address calculation, a location in the file is determined by a linear formula. It is placed there if the location is empty. If there is an item at the specified location, a search is made to find the closest empty space to this spot. The item at the specified location, together with adjacent items, is moved by a process similar to musical chairs, so that the item to be filed can be entered in its proper order in the file. A generalized flowchart for computer address calculation sorting is presented here. A mathematical analysis using average expectation follows. Formulas are derived to determine the number of computer operations required. Further formulas are derived which determine the time required for an address calculation sort in terms of specific computer orders. Several examples are given. A sorting problem solved elsewhere in the literature by an empirical method is solved by the formulas developed here to demonstrate their practical application.

The role of signal structure in a signal discrimination system is discussed. The optimality criterion for reference signals for detection in the case of white Gaussian independent noise is defined. The need for normalization of the reference signals is demonstrated. A geometric interpretation is presented. Optimum classes are obtained and several examples cited. A theoretical optimum class of signals is derived against which any set of signals developed within given constraints may be rated.

When a character printed in magnetic ink passes beneath a magnetic reading head it generates a waveform. A method is described here to determine this waveform from the geometry of the printed character. The character shape is divided into elementary vertical units and the height of these units is then tabulated. A single set of experimental data is obtained in the laboratory by passing a magnetically printed bar beneath the same reading head which will be used to read the characters. Formulas are derived in this paper for combining the geometrical data obtained from the character with the experimental data obtained from the laboratory run with the head. A method is then described for programing a high-speed digital computer to derive the waveforms. The discussion explains why these waveforms are often superior to what might be obtained in an actual laboratory run of the printed characters.

Many papers have been written about the reflected binary system and it is well known in the computer field for analog-to-digital conversion. The method used in creating this system may be extended to systems of bases other than two. It is the purpose of this paper to carry this extension to its logical conclusion. The author describes how reflected systems of different bases may be composed. The equations for translating between the conventional and reflected systems are then derived. It is also demonstrated how the reflected binary system is a special case of reflected number systems and how the general case simplifies for the reflected binary case.