SIRIUS Autocode(ID:6620/sir004)Autocode for the Ferranti SirusRelated languages
References: Introduction Electronic computers are able to work at high speeds only because they are programmed. Analysis of a problem, or a data processing procedure, and the programming of it for a computer in machine code, is a laborious task. In the early machines, users soon appreciated the advantage of having standard programs for assembly and program development, and a library of routines for regular calculations, complex number input and output, and for tracing the course of programs during program development, particularly when unexpected results were given when the program was tried on the machine. Where jobs are to be done regularly, it is still most economical, in the long run, to program them in machine language using such library routines as may be available. But for jobs which have to be done only once, or where it is desirable to try-out part of the job first and then extend the application of the computer, simplified programming systems have been developed. By their means, the computer can be addressed in a form of English, or by direct use of mathematical symbols if these are available in the character set of the teleprinter-punch used for punching the program. These simplified programming systems to which I shall apply the term "Autocodes" (originally named by Brooker at Manchester), together with available libraries of programs, constitute a very significant extension of the machinery which is now available. Besides saving the time spent on programming, these systems reduce the clerical errors of program writing by eliminating many tedious steps and this also reduces the time taken by program development. They also make it easier for the writer (or another person) to amend the program at a later date. In the earlier systems, the simplification entailed a varying loss of operating speed, varying between two and fifteen times as long to do a job on the machine. But a half hour of computer time after a few hours' programming in autocode is a more economic proposition for a one-off job, or trial of a routine job, than several weeks on programming, followed, after several trials, by a successful five-minute run on the computer. The newer programming systems, which involve a preliminary operation to compile a machine code program, will suffer less loss of speed and will become the normal method of programming computers for calculations and dataprocessing work, where the operations are not sufficiently standard to justify the writing of specific or general programs in machine language. Extract: Work at Rothamsted Work at Rothamsted In his valedictory Presidential address to The British Computer Society in London on 26 September 1961, Dr. Frank Yates reviewed the contribution which computers have made and are making in research statistics. It is on the solution of problems involving heavy numerical computation, in pure research, and in engineering design that, in his view, computers have achieved their most striking successes: Dr. Yates went on to point out that even in fields where computational tasks had previously been performed on desk calculators, computers could introduce three new features: (a) Speed, e.g. where further progress depends on knowing results to date. (b) A more thorough job, with better editing of data and more accurate calculations. (c) Relegation of computational methodology to the machine, so that people requiring to do calculations do not have to know the detail of the calculations involved. His paper (Yates, 1962), published in the January issue of The Computer Journal, reviews experience at Rothamsted and the development there of general programs for statistical work and some autocodes at other centres. If a general purpose program is available to include a mathematical procedure or the statistical method which one needs for a piece of analysis, then more people can use the computer. 1 have prepared a schedule of some of the schemes that are now available, or may be expected to be available early in 1962. Those who have access to a computer may find this of interest to follow up whichever line of development is applicable. Extract: Applications in Metal Box Company Applications in Metal Box Company In a paper published in The Computer Journal for April 1961 (Gearing 1961) 1 referred to the use which we, in The Metal Box Company Limited, had made of Pegasus autocode. I reviewed, in some detail, two programs. One of these was an analysis of a market survey for household trays in which interviews were conducted with some 1,100 households, covering 17 general questions and 10 observations of each tray found at the house: these questionnaires were analysed and 17 tables for the internal report were printed direct from the computer output tape. The other program related to part of our work on experimental sales forecasting and is now available in the Pegasus/Sirius interchange scheme (Ferranti, 1960). Our first computer application to quality control was in 1958-59 when we undertook an analysis of variance in connection with a productive operation being camed out by a group of machines in the chain between the sheet of tinplate and the finished open top can. Three factors were involved. The autocode program for Pegasus was thought to be rather slow and a full machine code program was written by Mr. D. Bulcock and is now available in the Pegasus interchange scheme. There are other analyses of variance programs available, notably one by BISRA (Caner and Taylor, 1960) which caters for up to seven factors, but if there are more than seven levels and only three factors involved, our program permits all the levels of data to be used. Nowadays, we would not attempt to write a full machine code program unless the job was going to be frequently done and would require considerable machine time. In the group of machines which we are using, a compiler-program has become available which automatically translates the Pegasus autocode program into Sirius machine orders (Ferranti, 1959 and 1961). In 1960 we were asked to assist in the analysis of data on the variability of some raw material which had been collected from sampled consignments over two years. Several different characteristics of the material had been measured. An autocode program was wntten to analyse each characteristic separately, prmting sample means, ranges, standard dev~ations, and compiling frequency distributions of means and standard deviations. A hierarchic analysis of variance was also given at the end of each characteristic. We were asked to undertake this work on 29 March and the calculations were substantially completed on 12 Aprll. Further calculations and a correlation between two characteristics were made on 3 June and 5 October 1960. Here I would like to stress that although the program was written in autocode, which is normally advocated for one-off jobs, the program is a general one. The progress of the calculations is controlled by ten parameters and the print routine by seven more. Thus one program served for the analysis of all the different characteristics, including some that involved preliminary arithmetic on pairs of observations. The correlation program was written separately but took only two hours to write, using pairs of exlsting data tapes fed in on the two tape readers simultaneously. Extract: Scientific Autocodes Scientific Autocodes The list appended covers a wide range of programs. compilers, autocodes. Among the autocodes which can be taught in a few days and which are already fully operational are : Mercury autocode. Pegasus/Sirius autocode. Ferranti Matrix Interpretive Scheme. Deuce Alphacode. IBM Fortran. Edsac 2 Autocode. Stantec Zebra Simple Code. Elliott 803 autocode. Elliott and other systems based on ALGOL Extract: Commercial Autocodes Commercial Autocodes Those concerned with Commercial Data Processing should have a look at: ICT Rapidwrite-Cobol. Ferranti Nebula. Cleo & Gypsy when available. These may take a couple of weeks to study, because, speaking from experience with Nebula, there are not only procedure descriptions but also file outlines and specifications of format of data and results when dealing with computers having considerable ancillary equipment. The Scientific Autocodes are usually concerned with one medium of inputloutput only, punched tape or punched-cards. Programming a data processing operation in a Commercial Autocode like Nebula becomes a full-time job; but it is easier to train staff in Nebula than a machine code and the autocode compiler will (we hope) take care of housekeeping routines when opening and closing files. We are using young men and women of O level mathematics, who have had experience of controlling our punched card routines, for this work. in The Computer Bulletin March 1962 view details General Information Pegasus and Sirius are the names of computers made by Ferranti Ltd., of Manchester. Pegasus is a medium-sized, medium-speed machine with a magnetic drum store of 8192* words capacity, working in fixed-point binary arithmetic, with a word length of 39 binary digits which corresponds to 11 decimal places. Sirius is a more compact machine, working in decimal. The store is normally 4000 words but is extendable to a theoretical maximum of 10000 words, a word holding 10 decimal digits. Both machines use paper tape as their input and output media, using the code given in the Appendix. The autocodes used for the two machines are practically identical and everything in this chapter applies to both unless otherwise stated. in The Computer Bulletin March 1962 view details The preface states that "this book is intended to serve as an introduction to the programming of automatic computers." The first 24 pages present such an introduction, apparently assuming that this is the reader's first contact with a stored-program digital Computer. Part II, which makes up about 60 percent of this short volume, consists of three chapters, each of which describes a different autocode. The word "autocode" as used in England corresponds roughly to "compiler language') in the United States. The authors apparently consider an autocode to be machine-dependent, in contrast to a "universal computing language" like Algol, which is machine independent. The three autocodes discussed are for the Pegasus-Sirius, the Elliott 803, and the Ferranti Mercury. The machines themselves are not described here in any detail. They are all rather small machines, and are not of very great general interest. Unfortunately, the Same is true of their autocodes. The Mercury autocode is treated at greatest length and in greatest detail. It is an interesting system, but its interest is now mostly historical, illustrating some of the early work of Brooker and his colleagues at Manchester. Most of the material in this book will be of interest only to the devoted specialist and perhaps to the historian in the field of computer languages. A final section of the book presents a 14-page discussion of Algol. It is a good but very brief resume of the language. in The Computer Bulletin March 1962 view details The preface states that "this book is intended to serve as an introduction to the programming of automatic computers." The first 24 pages present such an introduction, apparently assuming that this is the reader's first contact with a stored-program digital Computer. Part II, which makes up about 60 percent of this short volume, consists of three chapters, each of which describes a different autocode. The word "autocode" as used in England corresponds roughly to "compiler language') in the United States. The authors apparently consider an autocode to be machine-dependent, in contrast to a "universal computing language" like Algol, which is machine independent. The three autocodes discussed are for the Pegasus-Sirius, the Elliott 803, and the Ferranti Mercury. The machines themselves are not described here in any detail. They are all rather small machines, and are not of very great general interest. Unfortunately, the Same is true of their autocodes. The Mercury autocode is treated at greatest length and in greatest detail. It is an interesting system, but its interest is now mostly historical, illustrating some of the early work of Brooker and his colleagues at Manchester. Most of the material in this book will be of interest only to the devoted specialist and perhaps to the historian in the field of computer languages. A final section of the book presents a 14-page discussion of Algol. It is a good but very brief resume of the language. in The Computer Bulletin March 1962 view details in The Computer Bulletin March 1962 view details |