An Interview with Niklaus Wirth
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Typology of Programming Languages E Early Languages E
Typology of programming languages e Early Languages E Typology of programming languages Early Languages 1 / 71 The Tower of Babel Typology of programming languages Early Languages 2 / 71 Table of Contents 1 Fortran 2 ALGOL 3 COBOL 4 The second wave 5 The finale Typology of programming languages Early Languages 3 / 71 IBM Mathematical Formula Translator system Fortran I, 1954-1956, IBM 704, a team led by John Backus. Typology of programming languages Early Languages 4 / 71 IBM 704 (1956) Typology of programming languages Early Languages 5 / 71 IBM Mathematical Formula Translator system The main goal is user satisfaction (economical interest) rather than academic. Compiled language. a single data structure : arrays comments arithmetics expressions DO loops subprograms and functions I/O machine independence Typology of programming languages Early Languages 6 / 71 FORTRAN’s success Because: programmers productivity easy to learn by IBM the audience was mainly scientific simplifications (e.g., I/O) Typology of programming languages Early Languages 7 / 71 FORTRAN I C FIND THE MEAN OF N NUMBERS AND THE NUMBER OF C VALUES GREATER THAN IT DIMENSION A(99) REAL MEAN READ(1,5)N 5 FORMAT(I2) READ(1,10)(A(I),I=1,N) 10 FORMAT(6F10.5) SUM=0.0 DO 15 I=1,N 15 SUM=SUM+A(I) MEAN=SUM/FLOAT(N) NUMBER=0 DO 20 I=1,N IF (A(I) .LE. MEAN) GOTO 20 NUMBER=NUMBER+1 20 CONTINUE WRITE (2,25) MEAN,NUMBER 25 FORMAT(11H MEAN = ,F10.5,5X,21H NUMBER SUP = ,I5) STOP TypologyEND of programming languages Early Languages 8 / 71 Fortran on Cards Typology of programming languages Early Languages 9 / 71 Fortrans Typology of programming languages Early Languages 10 / 71 Table of Contents 1 Fortran 2 ALGOL 3 COBOL 4 The second wave 5 The finale Typology of programming languages Early Languages 11 / 71 ALGOL, Demon Star, Beta Persei, 26 Persei Typology of programming languages Early Languages 12 / 71 ALGOL 58 Originally, IAL, International Algebraic Language. -
Simula Mother Tongue for a Generation of Nordic Programmers
Simula! Mother Tongue! for a Generation of! Nordic Programmers! Yngve Sundblad HCI, CSC, KTH! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Inspired by Ole-Johan Dahl, 1931-2002, and Kristen Nygaard, 1926-2002" “From the cold waters of Norway comes Object-Oriented Programming” " (first line in Bertrand Meyer#s widely used text book Object Oriented Software Construction) ! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Simula concepts 1967" •# Class of similar Objects (in Simula declaration of CLASS with data and actions)! •# Objects created as Instances of a Class (in Simula NEW object of class)! •# Data attributes of a class (in Simula type declared as parameters or internal)! •# Method attributes are patterns of action (PROCEDURE)! •# Message passing, calls of methods (in Simula dot-notation)! •# Subclasses that inherit from superclasses! •# Polymorphism with several subclasses to a superclass! •# Co-routines (in Simula Detach – Resume)! •# Encapsulation of data supporting abstractions! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Simula example BEGIN! REF(taxi) t;" CLASS taxi(n); INTEGER n;! BEGIN ! INTEGER pax;" PROCEDURE book;" IF pax<n THEN pax:=pax+1;! pax:=n;" END of taxi;! t:-NEW taxi(5);" t.book; t.book;" print(t.pax)" END! Output: 7 ! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! -
Internet Engineering Jan Nikodem, Ph.D. Software Engineering
Internet Engineering Jan Nikodem, Ph.D. Software Engineering Theengineering paradigm Software Engineering Lecture 3 The term "software crisis" was coined at the first NATO Software Engineering Conference in 1968 by: Friedrich. L. Bauer Nationality;German, mathematician, theoretical physicist, Technical University of Munich Friedrich L. Bauer 1924 3/24 The term "software crisis" was coined at the first NATO Software Engineering Conference in 1968 by: Peter Naur Nationality;Dutch, astronomer, Regnecentralen, Niels Bohr Institute, Technical University of Denmark, University of Copenhagen. Peter Naur 1928 4/24 Whatshouldbe ourresponse to software crisis which provided with too little quality, too late deliver and over budget? Nationality;Dutch, astronomer, Regnecentralen, Niels Bohr Institute, Technical University of Denmark, University of Copenhagen. Peter Naur 1928 5/24 Software should following an engineering paradigm NATO conference in Garmisch-Partenkirchen, 1968 Peter Naur 1928 6/24 The hope is that the progress in hardware will cure all software ills. The Oberon System User Guide and Programmer's Manual. ACM Press Nationality;Swiss, electrical engineer, computer scientist ETH Zürich, IBM Zürich Research Laboratory, Institute for Media Communications Martin Reiser 7/24 However, a critical observer may notethat software manages to outgrow hardware in size and sluggishness. The Oberon System User Guide and Programmer's Manual. ACM Press Nationality;Swiss, electrical engineer, computer scientist ETH Zürich, IBM Zürich Research Laboratory, Institute for Media Communications Martin Reiser 8/24 Wirth's computing adage Software is getting slower more rapidly than hardware becomes faster. Nationality;Swiss, electronic engineer, computer scientist ETH Zürich, University of California, Berkeley, Stanford University University of Zurich. Xerox PARC. -
Oral History Interview with John Brackett and Doug Ross
An Interview with JOHN BRACKETT AND DOUG ROSS OH 392 Conducted by Mike Mahoney on 7 May 2004 Needham, Massachusetts Charles Babbage Institute Center for the History of Information Processing University of Minnesota, Minneapolis Copyright, Charles Babbage Institute John Brackett and Doug Ross Interview 7 May 2004 Oral History 392 Abstract Doug Ross and John Brackett focus on the background of SofTech and then its entry into the microcomputer software marketplace. They describe their original contact with the University of California at San Diego (UCSD) and licensing the p-System which had been developed there. They discuss the effort required to bring the program to production status and the difficulties in marketing it to the sets of customers. They talk about the transition from 8 bit to 16 bit machines and how that affected their market opportunities. They conclude with a review of the negotiations with IBM and their failure to get p-System to become a primary operating environment. That, and the high performance of Lotus 1-2-3, brought about the demise of the p- System. [John Brackett requested that the following information from Wikipedia, the free encyclopedia, be provided as an introduction to this oral history interview: “UCSD p-System or UCSD Pascal System was a portable, highly machine independent operating system based upon UCSD Pascal. The University of California, San Diego Institute for Information Systems developed it in 1978 to provide students with a common operating system that could run on any of the then available microcomputers as well as campus DEC PDP-11 minicomputers. UCSD p- System was one of three operating systems (along with PC-DOS and CP/M-86) that IBM offered for its original IBM PC. -
Type Extensions, Wirth 1988
Type Extensions N. WIRTH lnstitut fijr Informatik, ETH, Zurich Software systems represent a hierarchy of modules. Client modules contain sets of procedures that extend the capabilities of imported modules. This concept of extension is here applied to data types. Extended types are related to their ancestor in terms of a hierarchy. Variables of an extended type are compatible with variables of the ancestor type. This scheme is expressed by three language constructs only: the declaration of extended record types, the type test, and the type guard. The facility of extended types, which closely resembles the class concept, is defined in rigorous and concise terms, and an efficient implementation is presented. Categories and Subject Descriptors: D.3.3 [Programming Languages]: Language Constructs-data types and structures; modules, packuges; D.3.4 [Programming Languages]: Processors-code generation General Terms: Languages Additional Key Words and Phrases: Extensible data type, Modula-2 1. INTRODUCTION Modern software development tools are designed for the construction of exten- sible systems. Extensibility is the cornerstone for system development, for it allows us to build new systems on the basis of existing ones and to avoid starting each new endeavor from scratch. In fact, programming is extending a given system. The traditional facility that mirrors this concept is the module-also called package-which is a collection of data definitions and procedures that can be linked to other modules by an appropriate linker or loader. Modern large systems consist, without exception, of entire hierarchies of such modules. This notion has been adopted successfully by modern programming languages, such as Mesa [4], Modula-2 [8], and Ada [5], with the crucial property that consistency of interfaces be verified upon compilation of the source text instead of by the linking process. -
ETH Eidgenossische Technische Hochschule Zurich H.Eberle
ETH Eidgenossische lnstitut Technische fur lnformatik Hochschule ZUrich H.Eberle Hardware Description of the Workstation Ceres 11nuar 1987 ,70 70 . 61 .10 ETH Eidgenossische lnstitut Technische fur lnformatik Hochschule Zurich Eidrg. ~hn. ZI!rich lrricrm!!~!~:.~~lb;i::1H1a-k ETH~Zentrum CH..oo92 Zurich H.Eberle Hardware Description of the Workstation Ceres EidQ. lechn. He:ch'?~h'Jle Zilr\J::;!-: lnforme::!':.uib~iuthek El'l I-lei ili rn 11 CH-8002 ZOrtch gl,4-,23 Address of the author: lnstitut fiJr lnformatik ETH-Zentrum CH-8092 Zurich I Switzerland © 1987 lnstitut tor lnformatik, ETH Zurich 1 Hardware Description of the Workstation Ceres H.Eberle Abstract Ceres is a single-user computer based on the 32-bit microprocessor NS32000. The processor is oriented to the use of high-level languages. The hardware design concentrates on simplicity and modularity. The key features are the arbitrated memory bus and the high resolution bitmapped graphics display which promotes the attractivity of a programming workstation. This paper documents the hardware of the Ceres computer. 2 Contents 1 Introduction 3 2 Hardware Structure 4 2.1 Processor 4 2.2 Primary Memory 4 2.3 Secondary Memory 4 2.4 Input/Output Devices 4 3 Hardware Implementation 6 3.1 Processor Board 6 3.1.1 Processor 6 3.1.2 Memory Bus Arbiter 9 3.1.3 Boot ROM and Standard Input/Output Devices 12 3.2 Memory Board 15 3.3 Display Controller Board 18 3.3.1 Display Memory 18 3.3.2 Display Refresh Controller 19 3.4 Disk Controller Board 23 3.5 Motherboard 23 4 Hardware Extensions 24 References 26 Appendices A Circuit Diagrams 28 A.1 Processor Board 28 A.2 Memory Board 35 A.3 Display Controller Board 37 B PAL Design Specifications 42 c Interface Connectors 47 C.1 Processor Board 47 C.2 Display Controller Board 48 C.3 Motherboard 48 3 1 Introduction Todays working tools of a software engineer at the lnstitut fUr lnformatik of ETH ZOrich are the programming language Modula-2 [1] and the workstation computer Lilith [2]. -
Latest Results from the Procedure Calling Test, Ackermann's Function
Latest results from the procedure calling test, Ackermann’s function B A WICHMANN National Physical Laboratory, Teddington, Middlesex Division of Information Technology and Computing March 1982 Abstract Ackermann’s function has been used to measure the procedure calling over- head in languages which support recursion. Two papers have been written on this which are reproduced1 in this report. Results from further measurements are in- cluded in this report together with comments on the data obtained and codings of the test in Ada and Basic. 1 INTRODUCTION In spite of the two publications on the use of Ackermann’s Function [1, 2] as a mea- sure of the procedure-calling efficiency of programming languages, there is still some interest in the topic. It is an easy test to perform and the large number of results ob- tained means that an implementation can be compared with many other systems. The purpose of this report is to provide a listing of all the results obtained to date and to show their relationship. Few modern languages do not provide recursion and hence the test is appropriate for measuring the overheads of procedure calls in most cases. Ackermann’s function is a small recursive function listed on page 2 of [1] in Al- gol 60. Although of no particular interest in itself, the function does perform other operations common to much systems programming (testing for zero, incrementing and decrementing integers). The function has two parameters M and N, the test being for (3, N) with N in the range 1 to 6. Like all tests, the interpretation of the results is not without difficulty. -
Reception of Pascal in the History of Sciences
Reception of Pascal in the history of sciences... Camille Akmut April 27, 2020 Abstract In particular computer science and technologies. With references to the history of philosophy and the social sciences. 1 I - Crown jewel computers, and sciences The computer scientist Niklaus Wirth, creator of the Pascal programming language, has said of the origins of his creation : I named it after the French philosopher and mathematician, who in 1642 designed one of the first gadgets that might truly be called a digital calculator.1 This is how Wirth remembered Pascal, and explained his choice of the philosopher for his namesake language in 1993 as part of a large conference organized by the ACM on the history of programming languages (the second HOPL); as a pioneer in a line from which { it is either implied, or we interpret too strongly { he ultimately descended. Another notable computer scientist, Friedrich Bauer, known for the stack ADT and his participation in the making of ALGOL 602 among others, in his 'Historical notes on computer science' (one of his last books, if not the last) expressed the following judgment on Pascal and Schickard : \We would not do Schickard any justice by exaggerating : his cal- culating machine was no 4-type ["Vier-Species"] machine, like that of Leibniz, but only a 2-type like Pascal's, but with the difference of having come twenty years earlier. Kepler was said to have been most happy with it. And, perhaps its mechanism was superior. But, that would be a detail."3 [trans.] Ergo : the real machine was Leibniz's { as it could (really) do all four operations of arithmetic { and as for the earlier, partial or lesser, ones Schickard's 1Found in History of programming languages, vol. -
Niklaus Wirth—A Pioneer of Computer Science 1
Niklaus Wirth—A Pioneer of Computer Science 1 Niklaus Wirth — a Pioneer of Computer Science Gustav Pomberger, Hanspeter Mössenböck, Peter Rechenberg Johannes Kepler University of Linz [email protected], [email protected], [email protected] Abstract Niklaus Wirth is one of the most influential scientists of the early computer age. His ideas and especially his programming languages have shaped gen- erations of programmers worldwide. This paper tries to acknowledge the scientific achievements of Niklaus Wirth and to honor him as a person. A small part of the paper is also devoted to Wirth's influence on computer sci- ence at the Johannes Kepler University of Linz. 1 Introduction Ask computer specialists anywhere—be it in Europe or America, in Asia or Australia—who the most important computer scientists in the world are, and you can bet that the name Niklaus Wirth will be on every list. Ask programming language experts about the person with the greatest influence on the development of programming languages, and they would agree on Niklaus Wirth. Ask students, teachers and computer hobbyists about the most important programming lan- guages, and you can be sure that even today Pascal will be on every list. Finally, examine the literature of computer science in the elite circle of books with the greatest number of copies printed, the widest distribution, and the most transla- tions, and you will find books by Niklaus Wirth, especially the prominent book on Pascal. These few examples show that professor Niklaus Wirth is one of the world's leading computer scientists. -
Cs 98 Algol W Implementat Ion by H. Bauer S. Becker S
CS 98 ALGOL W IMPLEMENTAT ION BY H. BAUER S. BECKER S. GRAHAM TECHNICAL REPORT NO. CS 98 MAY 20, 1968 COMPUTER SC IENCE DEPARTMENT School of Humanities and Sciences STANFORD UNIVERS llTY ALGOL W IMPLEMENTATION* -- H, Bauer S. Becker S. Graham * This research is supported in part by the National Science Foundation under grants GP-4053 and ~~-6844. -ALGOL -W IMPLEMENTATION Table -.of Contents ,, 1, Introduction . ..~.........*0.~.**.e.....*.....".....* XI. General Organization . ..os.*..e.~*....~****.*..*.. 3 lX1. Overall Design . ..*.0~....~..~e~eo~o.e...e.....*~~.... 4 A. Principal Design Considerations . ..*......** 4 B. Run-Time Program and Data Segmentation ., ,,,... 6 C. Pass One . ..~D..O......~e~~.*~.*~.....~.. 7 D. Pass Two . ..*..eOC~O.4....*~~..~...~..~~....~ 8 1. Description of Principles and -=. Main Tasks .*0*.*.......0~,00*..*..* 8 2. Parsing Algorithm . ...*......**.* 8 3* Error Recovery .0....~..~.~.~.,~,~~~, 9 4. Register Analysis . ..*.......*.... 11 L- 5* Tables *.....@.,..*......e..*.*.y...* 13 6. Output ,.......*..*0..00..0*~~..~... 13 E. Pass Three . ..0......*....e...e..e.e........*, 16 L l-v. Compiler Details . ..~..~~~...~~~~.~~.....~..~... 17 A. Run-Time Organization ..~*0**~..*~...~...*~..., 17 1. Program and Data Segmentation ,,.,., 17 2. Addressing Conventions . ..*.9..*..** 20 30 Block Marks and Procedure Marks ,.., 20 4. Array Indexing Conventions . ..I.# 22 5. Base Address Table and Lirikage to System Routines . ..****..o....*.. 23 6. Special Constants and Error Codes ,. 24 Register Usage ..OI.OI.O,,..O..L,..~ 27 ;3** Record Allocation and Storage Reclamation .0.0.~.~*0*~0..~~~.**, 27 B. Pass We r....oc.o....o....o..~.*..~*.,.,.....* 33 1. Table Formats Internal to Pass One . ..0...*ee..o...Q....*.~.* 3c 2. The Output String Representing an ALGOL W Program l . -
Modula-2 and Oberon
Modula-2 and Oberon Niklaus Wirth ETH Zurich [email protected] Abstract scientific circles and COBOL in business data processing. IBM’s PL/I was slowly gaining acceptance. It tried to unite the disparate This is an account of the development of the languages Modula-2 worlds of scientific and business applications. Some further, and Oberon. Together with their ancestors ALGOL 60 and Pascal "esoteric" languages were popular in academia, for example Lisp they form a family called Algol-like languages. Pascal (1970) and its extensions, which dominated the AI culture with its list- reflected the ideas of structured programming, Modula-2 (1979) processing facilities. added those of modular system design, and Oberon (1988) catered However, none of the available languages was truly suitable to the object-oriented style. Thus they mirror the essential for handling the ever-growing complexity of computing tasks. programming paradigms of the past decades. Here the major FORTRAN and COBOL lacked a pervasive concept of data types language properties are outlined, followed by an account of the like that of Pascal; and Pascal lacked a facility for piecewise respective implementation efforts. The conditions and the compilation, and thus for program libraries. PL/1 offered environments in which the languages were created are elucidated. everything to a certain degree. Therefore it was bulky and hard to We point out that simplicity of design was the most essential master. The fact remained that none of the available languages guiding principle. Clarity of concepts, economy of features, was truly satisfactory. efficiency and reliability of implementations were its I was fortunate to be able to spend a sabbatical year at the new consequences. -
50 Years of Pascal Niklaus Wirth the Programming Language Pascal Has Won World-Wide Recognition
50 Years of Pascal Niklaus Wirth The programming language Pascal has won world-wide recognition. In celebration of its 50th birthday I shall remark briefly today about its origin, spread, and further development. Background In the early 1960's, the languages Fortran (John Backus, IBM) for scientific, and Cobol (Jean Sammet, IBM and DoD) for commercial applications dominated. Programs were written on paper, then punched on cards, and one waited for a day for the results. Programming languages were recognized as essential aids and accelerators of the hard process of programming. In 1960, an international committee published the language Algol 60. It was the first time that a language was defined by concisely formulated constructs and by a precise, formal syntax. Already two years later it was recognized that a few corrections and improvements were needed. Mainly, however, the range of applications should be widened, because Algol 60 was intended for scientific calculations (numerical mathematics) only. Under the auspices of IFIP a Working Group (WG 2.1) was established to tackle this project. The group consisted of about 40 members with almost the same number of opinions and views about what a successor of Algol should look like. There ensued many discussions, and on occasions the debates ended even violently. Early in 1964 I became a member, and soon was requested to prepare a concrete proposal. Two factions had developed in the committee. One of them aimed at a second, after Algol 60, milestone, a language with radically new, untested concepts and pervasive flexibility. The other faction remained more modest and focused on realistic improvements of known concepts.