Outline:

  1. Overview
    1. Introduction
    2. Objectives
  2. History of Simula
    1. Players
    2. Raison D’être
    3. Time Line
  3. C++ Comparison
    1. Players
    2. Raison D’être
    3. Dependencies
  4. Applications of Simula

 

Overview

Introduction

 

 

 

Note Cards

 

History

http://www.engin.umd.umich.edu/CIS/course.des/cis400/simula/simula.html

The SIMULA programming language was designed and built by Ole-Johan Dahl and Kristen Nygaard at the Norwegian Computing Center (NCC) in Olslo between 1962 and 1967. It was originally designed and implemented as a language for discrete event simulation, but was later expended and reimplemented as a full sacle general purpose programming language.

 

Kristen Nygaard (left) and Ole-Johan Dahl are also Commanders of the Norwegian Order of St. Olav and recipients of the John von Neumann Medal.

http://www.simula.no/news_one.php?news_id=15

-- The ACM has presented the 2001 A.M. Turing Award, considered the “Nobel Prize of Computing,” to Ole-Johan Dahl and Kristen Nygaard of Norway for their role in the invention of object-oriented programming, the most widely used programming model today. Their work has resulted in reusable, reliable, scalable applications that have streamlined the process of writing software code and facilitated software programming. Current object-oriented programming languages include C++ and Java, both widely used in programming for personal computers, home entertainment devices, and standalone arcade applications. The A.M.Turing Award carries a $25,000 prize.

Nygaard and Dahl have also been awarded the John von Neumann Medal for 2002, which is awarded by The Institute of Electrical and Electronics Engineers (IEEE) and is of the same importance as the Turin Award (see article). They have previously been recognised as Commanders of the Norwegian Order of St. Olaf for their contribution to the development of computer technology.

The Simula languages, developed by Dahl and Nygaard at the Norwegian Computing Center in Oslo in the 1960’s, have enabled software programmers to build in layers of abstraction, each one relying on a platform implemented by the lower layers. Their discrete event simulation language (Simula I) and general programming language (Simula 67) have resulted in programming that is both accessible and available to the entire research community.

“The work of Drs. Dahl and Nygaard has been instrumental in developing a remarkably responsive programming language that is both flexible and agile when applied to software design,” said John R. White, executive director and CEO of ACM. “It is the dominant style for implementing complex programs with large numbers of interacting components.” The awards committee noted that the core concepts embodied in their object-oriented methods were designed for both system description and programming and provided not just a logical but a notational basis for their ideas. The benefits of their work are not limited to software but are applicable to business processes as well.

by Cheryl Gribble

Bjarne Stroustrup, the creator of C++, at Bell Labs

Bjarne Stroustrup

C++ was written by  Bjarne Stroustrup  at Bell Labs during 1983-1985. C++ is an extension of C.  Prior to 1983, Bjarne Stroustrup added features to C and formed what he called "C with Classes". He had combined the Simula's use of classes and object-oriented features with the power and efficiency of C. The term C++ was first used in 1983.

 

 

 

 

Significant Language Features

http://www.engin.umd.umich.edu/CIS/course.des/cis400/simula/simula.html

Although SIMULA is an extension of the programming language ALGOL 60, it is not a true extension of it. SIMULA retains the spirit of ALGOL 60 and includes that language as a subset, except for some monor exceptions. The following changes were made to the Kernel:

The default parameter mode is not call by name as it is in ALGOL 60. For value type variables it is call by value; for all other quantities it is call by reference.-

All variables are initialized in SIMULA according yo their type. This include also the “result variable” in function procedures. ALGOL 60 insists that at least one assignment be made to a result variable. This is not necessary in SIMULA.

 

Areas of Application

http://www.engin.umd.umich.edu/CIS/course.des/cis400/simula/simula.html

Although SIMULA never became widely used, the language has been highly influential on modern programming methodololy. Among other things SIMULA introduced important Object-Oriented programming concepts like classes and objects, inheretance and dynamic binding. But it is mainly used in the area of:

Discrete Event Simulation

 

Source Code: Simula

http://www2.latech.edu/~acm/helloworld/simula.html

 

Begin

        while 1 = 1 do begin

                outtext ("Hello World!");

                outimage;

        end;

End;

Source Code: Simula

http://internet.ls-la.net/mirrors/99bottles/beer_s_z.html#simula

 

BEGIN

  COMMENT

     Simula version of 99 beers

     Maciej Macowicz (mm@cpe.ipl.fr)

     Status: UNTESTED :)

  ;

  INTEGER bottles;

 

  FOR bottles:= 99 STEP -1 UNTIL 1 DO

  BEGIN

    OutInt(bottles,1);

    OutText("bottle(s) of beer on the wall, ");

    OutInt(bottles,1);

    Outtext("bottle(s) of beer");

    OutImage;

    Outtext("Take one down, pass it around, ");

    OutInt(bottles,1);

    OutText("bottle(s) of beer on the wall, ");

  END;

  OutText("1 bottle of beer on the wall, one bottle of beer.");

  Outimage;

  OutText("Take one down, pass it around, no more bottles of beer on the wall");

  OutImage

END

Source Code: Simula

 

http://www.engin.umd.umich.edu/CIS/course.des/cis400/simula/f1.html#source

 

BEGIN INTEGER X, N, SUM, MAX;

 

IF LASTITEM THEN OUTTEXT ("NULL LIST") ELSE

BEGIN SUM:=MAX:=ININT;

N:=1;

 

WHILE  LASTITEM DC

BEGIN X:=ININT;

N:=N+1;

IF X > MAX THEN MAX:=X;

SUM:=SUM+X;

END;

OUTTEXT("LIST LENGTH = ");      OUTINT (N, 6);

OUTTEXT(",            HIGHEST = ");     OUTINT (MAX, 6);

OUTTEXT(",      AVERAGE = ");   OUTFIX (SUM/N, 2,, 8);

 

END;

OUTIMAGE;

END

 

Sample Run

**INPUT 1:

**OUTPUT 1:

NULL LIST

 

**INPUT 2:

3 1 4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6

**OUTPUT 2:

LIST LENGTH=    21,     HIGHEST=        9,      AVERAGE=        4.90

Source Code: C++

http://www2.latech.edu/~acm/helloworld/c++.html

 

#include <iostream>

 

int main()

{

    std::cout << "Hello, world!\n";

}

Source Code: C++

http://internet.ls-la.net/mirrors/99bottles/beer_s_z.html#simula

 

// C++ version of 99 Bottles of beer

// programmer: Tim Robinson timtroyr@ionet.net

#include <fstream.h>

 

int main()

    {

    int bottles = 99;

    while ( bottles > 0 )

        {

        cout << bottles << " bottle(s) of beer on the wall," << endl;

        cout << bottles << " bottle(s) of beer." << endl;

        cout << "Take one down, pass it around," << endl;

        cout << --bottles << " bottle(s) of beer on the wall." << endl;

        }

    return 0;

    }

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

History

http://java.sun.com/people/jag/SimulaHistory.html

The SIMULA programming language was designed and built by Ole-Johan Dahl and Kristen Nygaard at the Norwegian Computing Centre (NCC) in Oslo between 1962 and 1967.[1] It was originally designed and implemented as a language for discrete event simulation, but was later expanded and reimplemented as a full scale general purpose programming language. Although SIMULA never became widely used, the language has been highly influential on modern programming methodology. Among other things SIMULA introduced important object-oriented programming concepts like classes and objects, inheritance, and dynamic binding.

 

Intro http://www.cetus-links.org/oo_simula.html

"As the name Simula suggests, this programming language was originally designed for the purpose of Simulation. The language was designed by Dahl, Myhrhaug and Nygaard at the Norwegian Computing Center, Oslo and the first version of the language, Simula-1, described in 1966, was strictly a Simulation language (like GPSS). Soon thereafter, influenced by Hoare's ideas on records, the designers realized that they could do dynamic modeling using a general purpose extensible language based on Algol-60. This led to Simula-67, described in the Simula Common Base report. The extension mechanisms were classes and prefixing, a form of inheritance with subtyping. Ten years later, the language was standardized and became known as simply Simula.

In addition to leading to modern Simula, Simula 67 was an inspiration to the Xerox Palo Alto Research Center (PARC) group who developed Smalltalk and to Bjarne Stroustrop in his development of C++. While Simula 67 had the central object-oriented concepts of inheritance and subtyping, much of the popular mystique surrounding objects and object-oriented design developed later as a result of other efforts, most notably the work of Alan Kay and his collaborators at Xerox PARC." (John Mitchell)

http://www.cis.um.edu.mt/~jskl/talk.html

This document is based on an IT seminar called 30 Years of Object Oriented Programming (OOP) held at the University of Malta on 5/12/1997. The first Object Oriented Language (OOL) Simula 67 was officially introduced by Ole Johan Dahl and Kristen Nygaard at the IFIP TC 2 Working Conference on Simulation Languages in Lysebu near Oslo in May 1967. 30 years represent one human and several computer generations. In spite of being in use for such a long time, all modern programming work carried out today is based on principles of OOP introduced for the first time in the Simula definition. And what is more important, Simula contains facilities that up to now have not been fully utilized and not even understood by not only general programming public but also people from OOP community. The purpose of the talk was a brief introduction of main Simula features, mainly those not present in other OOLs. The same is the purpose of this document.

SIMULA 67 HISTORY

(Source: Jan Rune Holmevik: Compiling Simula - see REFERENCES)

1965,66 Simula I used in Sweden, Germany, USA (Burroughs B5500), Soviet Union (URAL 16) and other countries. Effort to introduce and teach the language.

1965 Tony Hoare's record class concept presented in Algol bulletin. After a careful examination, Nygaard and Dahl accept the ideas, but a sort of generalized concept still missing.

1966 Introducing the idea of prefixing. Processes (later objects) made of two layers: prefix layer, main layer. Idea of subclasses. Nygaard and Dahl start work on a new general high-level language.

1967 (May). Simula 67 officially introduced by Dahl and Nygaard at the IFIP TC 2 Working Conference on Simulation Languages in Lysebu near Oslo.

1967 (June). Definition of Simula 67 standard called Common Base Standard.

1968 First meeting of Simula Standards Group (SSG). After accepting string handling and I/O done by Bjorn Myhrhaug, Simula formally frozen.

1973 Association of Simula Users (ASU) founded. Simula used in more than 250 sites that year.

Implementations:

1969 CDC 3300, 3600 (Norway - University of Oslo, NDRE)

1971 UNIVAC 1100 (NCC)

1972 IBM 360/370 (NCC)

1972 CII 10070, IRIS 80 (France)

1973/74 CDC 6000 (France, Netherlands), CDC Cyber 70 (NDRE)

1975 DEC 10 (Sweden) etc.

Periodicals:

Proceedings of annual ASU conferences (first 1973 Oslo, last 1997 Slovakia, next 1998 Kiel Germany

http://www.cis.um.edu.mt/~jskl/asu/index.html

The Simula language (used to be called Simula 67) is the first true object oriented language. Being more than 30 years old, it still has most (and all important) mechanisms and principles of OOP. Some things like classes, inheritance, virtual methods, etc. have been defined in Simula long time before they were rediscovered by the OOP boom in last years. To learn more about Simula, visit the page of ASU (Association of Simula Users) with many references.

http://www.cis.um.edu.mt/~jskl/talk.html#History%2067

 

Simula never became a widely spread commonly used language. There are various reasons to explain this fact. Even though the reasons all depend on each other, the following is an attempt to group them from various ponts of view.

Generally:

Born in a small European country

Frozen in 1968

Expensive

Does not have a modern IDE

Too complicated

Not enough publications

Language features:

Limited file access facilities (typed files)

Missing data types (records, sets)

No advanced parallelism and real time support

No GUI support

Long executable files for short programs

OOP features:

No multiple inheritance

No interfaces

Simulation:

No automatic collection of statistics

No report generator

No useful specialized facilities (resources)

 

 

 

 

 

 

 

REFERENCES http://www.cis.um.edu.mt/~jskl/talk.html#History%2067

Books/Papers

Birtwistle, G.M., O.-J. Dahl, B. Myhrhaug and K. Nygaard: SIMULA Begin, AUERBACH Publishers Inc, 1973.

Pooley, R.J.: An Introduction to Programming in SIMULA, Oxford, Blackwell Scientific Publications, 1987.

Kirkerud, B.: Object-Oriented Programming with SIMULA, Addison-Wesley, 1989.

Holmevik, J.R.(1994). " Compiling SIMULA: a historical study of technological genesis." IEEE Annals of the History of Computing, 16 (4), p. 25-37, 1994. The article was also presented at the 18th ASU Conference in 1992, and published in the SIMULA Newsletter Vol.20(1), October 1992.
Thanks to Mr. Holmevik's kind permission you can download a local copy of his paper Compiling SIMULA.

Other Holmevik paper on history of technology: The legacy of the Wizard War

Periodicals

Proceedings of annual ASU conferences. (First 1973 Oslo, last 1997 Stara Lesna - Slovakia, next 1998 Salzau - Germany).

ASU Newsletter

Web locations

DIRO Simula home is a Simula oriented page held at the Département d'informatique et recherche opérationnelle (Université de Montréal). It contains many very interesting ideas and further references.

ASU (Association of Simula Users) is housed at the ISIMA, Université Blaise Pascal, France. It contains (among others) information on ASU conferences and comprehensive bibliography.

http://www.iro.umontreal.ca/~simula

At the Université de Montréal, we recently ( 1994-1998 ) used Simula as the basic language to teach programming. This Web site was created at that time to help counteract the lack of information, software and support for the language. Since then, our department got overwhelmed by the Java Tidal Wave and Simula is only used peripherally. It is small consolation to us Simula fans that all students who were exposed to the language feel Simula would have been a much better base than C++ from which to develop "Java". [ Update - jan 2000; Now back to the original text ]

We had been using Simula in simulation courses since 1970 when we found it bundled on our CDC computer. Simula was also used for the main case study in our advanced OS course. This case study, which involves writing an operating system for a simulated computer, has been with us for over 20 years.

At the time, we thought Simula too exotic to use for basic programming; however, the recent OO craze (early 90's) made us re-evaluate OO languages (including Simula) for teaching. To our surprise, Simula turned out to be head and shoulders better than the competition in terms of simplicity, power, security and stability. To be fair, we should say that we did find it weak in 3 areas: availability of teaching material (books & cheap implementations), interactive graphics and popularity.

http://www.iro.umontreal.ca/~simula/SimBiblio.html

Simula Bibliography

 

 

Reference:

Birtwistle, G.M. (Graham M.) 1973. SIMULA begin. Philadelphia, Auerbach.

Sebesta, Robert (1996). Concepts of Programming Languages. Addison-Wesley Publishing, CA.

 

 

NOTES

http://java.sun.com/people/jag/SimulaHistory.html

[1]

This chapter is revised from an article published in the Annals of the History of Computing. Vol. 16(4), 1994; pp. 25-37. I gratefully acknowledge the many helpful comments and suggestions on earlier drafts offered by among others William Aspray, Martin Campbell-Kelly, Paul Ceruzzi, Michael S. Mahoney, Arthur L. Norberg, Nils Roll-Hansen, Knut H. Soerensen, and the referees of the Annals of the History of Computing.

[2]

See for instance: Hughes (1983) and Hughes (1989).

[3]

See Hughes (1986) and Latour (1987).

[4]

'A Status Report on SIMULA - A Language for the Description of Discrete Event Networks'. 13 July, 1963. NCC

[5]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 441.

[6]

Nygaard (1963, p. 520).

[7]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit.

[8]

ALGOL 60 represents a milestone in the history of programming languages, and during the 60s and 70s this language was the prime source of most theoretical work related to compiler design and development.

[9]

Interview with Ole Johan Dahl, 7 November, 1991.

[10]

NTNF's Annual Report 1958/59, p.82.

[11]

'Den fremtidige virksomhet ved Norsk Regnesentral', 3 May 1961. NCC.

[12]

The preceding account is primarily based on interviews with Kristen Nygaard 28 November, 1992, Karl Holberg 5 March, 1992, and Finn Lied 6 March, 1992.

[13]

NCC's Financial Accounts 1959, 1960.

[14]

'Den fremtidige virksomhet ved Norsk Regnesentral', 3 May, 1961. NCC.

[15]

Interview with Kristen Nygaard, 28 November, 1991.

[16]

'Forslag om anskaffelse av en elektronisk regnemaskin type UNIVAC-1107 til Norsk Regnesentral', innstilling fra raadets arbeidsutvalg. Fall 1962. NTNF. Please note that all US $figures in this chapter are based on US-Norwegian exchange rates listed in Historical Statistics 1978, p. 513.

[17]

Note from NTNF's director Robert Major. 19 July, 1962. NTNF.

[18]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 442.

[19]

This project was based on a new and promising algorithm for linear programming, denoted parametric decent, developed by Sverre Spurkland at NCC. Even though the project was based on a very powerful concept, and later on was to receive substantial financial support from Univac, it was never completed.

[20]

Letter from Robert W. Bemer to the author. 15 July, 1994.

[21]

Telephone interview with Robert W. Bemer, 14 April, 1992.

[22]

Nygaard (1963).

[23]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 455.

[24]

Ibid., p. 454.

[25]

Donald MacKenzie: 'The Influence of the Los Alamos and Livermore National Laboratories on the Development of Supercomputing' Annals of the History of Computing, Vol.13(2), 1991.

[26]

Interview with Kristen Nygaard, 28 November, 1991

[27]

Sperry Rand Univac's offer to NCC regarding UNIVAC 1107, 26 June, 1962, and 'Agreement made 1st. day of June by and between Sperry Rand Corporation (Univac) and the Royal Norwegian Council for scientific and industrial research'. 1 June, 1963. NTNF.

[28]

Telephone interview with Robert Bemer, 14 April, 1992, and letter >from Robert Bemer to the author, 29 July, 1992.

[29]

Letter from A. A. Cohen, Staff Scientist of the Data Processing Division to Kristen Nygaard. 23 October, 1964. NCC.

[30]

Raadet for elektronisk databehanding i staten. My translation.

[31]

Memo from Finn Lied to Karl Holberg. 11 May 1962. NDRE

[32]

His conclusion was largely drawn from a survey of computing needs in the Oslo area. In this survey Nygaard contacted a number of institutions that had previously benefited from his OR services and asked how they would make use of an eventual mainframe computer in the Oslo area. These were Aftenposten, Det Norske Veritas, Direktoratet for Statens Skoger, H. EEG Henriksen A/S, Kontroautomasjon A/S, Norsk Produktivitetsinstitutt, Oslo Kommune/ kommunikasjons-raadmannen, Oslo Kommune/ Likningskontoret, M. Petterson & Soenn A/S, Sentralinstituttet for Industriell Forskning, and Vegdirektoraet. Source: 'Forslag om anskaffelse av en stor elektronisk regnemaskin til Norsk Regnesentral'. September 1962. NTNF.

[33]

'Forslag om anskaffelse av en elektronisk regnemaskin type UNIVAC-1107 til Norsk Regnesentral', innstilling fra raadets arbeidsutvalg. Fall 1962. NTNF.

[34]

Lied referred to a meeting with Secretary of State Gudmumd Harlem where Harlem had expressed that if the acquisition of two computers was proposed at this stage this could lead to significant delays for both. Source: Minutes from the working committee's meeting 21 August 1962. NTNF

[35]

Minutes from the working committee's meeting 21 August 1962. NTNF

[36]

Note from NCC's director Leif K. Olaussen: 'Oversikt over forholdet mellom Norsk Regnesentral og Univac angaaende levering av den elektroniske regnemaskinen UNIVAC 1107 og tilhoerende programmeringssystemer', 15 January, 1965, and interview with Robert Major, 29 November, 1991.

[37]

Letter from NTNF's director Robert Major to NCC's director Bjoern OErjansen, 21 July, 1962. NTNF.

[38]

Note from Kristen Nygaard to the board of NCC, 22 January, 1964. NTNF.

[39]

Resolution from the board of NCC: 'Organisasjonsplan for Norsk Regnesentral', 11 December, 1962, and interview with Karl Holberg, 5 March, 1992. NTNF.

[40]

Resolution from the board of NCC: 'Organisasjonsplan for Norsk Regnesentral', 11 December, 1962, and interviews with: Bjoern OErjansen

[25]

November, Sverre Spurkland 27 November, Robert Major 29 November, 1991, and Karl Holberg 5 March, 1992. NTNF.

[41]

The title for this subsection is taken from Dahl, Ole-Johan and Nygaard, Kristen. 'SIMULA: A Language for Programming and Description of Discrete Event Systems. Introduction and User's Manual'. May 1965. NCC.

[42]

It should be added, that even though Dahl and Nygaard at this stage asserted that SIMULA should be ALGOL-based, they did not rule out a later version based on FORTRAN, using the same basic concepts.

[43]

Dahl O.-J. and Nygaard K: 'Preliminary presentation of the SIMULA Language (as of May 18th, 1963) and some examples of network descriptions'. NCC: May 1963.

[44]

Nygaard K. and Dahl O.-J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., pp. 447-448, and interview with Ole-Johan Dahl 7 November, 1991.

[45]

Dahl O.-J: 'The SIMULA Storage Allocation Scheme'. NCC Document no. 162, November 1963, and an interview with Ole-Johan Dahl, 7 November, 1991.

[46]

Interviews with Ole-Johan Dahl, 7 November, 1991 and 4 March, 1992, and Kristen Nygaard, 28 November, 1991

[47]

Quasi-parallel process execution implied that a main program could switch control from one process to another during a program run according to special sequencing statements. In SIMULA this sequencing was determined by the Hold statement, in addition to local reference variables in each inactive process, identifying where the control should resume operation the next time the process was activated. (Source: Dahl O.-J: 'The SIMULA Data Structures', NCC Document, February/ March 1964).

[48]

Letter from Ole-Johan Dahl to the author, 10 April, 1992.

[49]

Dahl and Nygaard (1965, p. 2).

[50]

Nygaard, Kristen. 'Report on the Use of SIMULA up to December 1965.' December 1965. NCC.

[51]

Ibid.

[52]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., pp. 459-461.

[53]

Interview with Ole-Johan Dahl, 4 March, 1992.

[54]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p 459-461.

[55]

International Federation for Information Processing's Technical Committee 2 was a committee especially dedicated to programming languages.

[56]

Buxton (1968, pp.337-338)

[57]

I use that term even if didn't exist in the 1950s and early `60s. Back then these people were mathematicians and the field they were working in was commonly referred to as applied mathematics.

[58]

F. G. Duncan and A. van Wijngaarden. 'Cleaning up ALGOL 60'. ALGOL Bulletin, AB16.3.3, May 1964.

[59]

For further reference, see: C. H. Lindsey. 'A History of Algol 68.' ACM/SIGPLAN Notices, Vol. 28(3), March 1993; pp. 97-132.

[60]

Buxton (1968, p. 345).

[61]

Dahl O.-J., and Nygaard K: 'Class and subclass declarations'. NCC Document, March 1967.

[62]

After having designed the systems descriptions language DELTA (1973-1975), in the second half of the 1970s, Kristen Nygaard together with research scientists from the University of AArhus and the University of AAlborg Denmark, embarked upon yet another language development project called BETA. The basic idea behind this project was the very same that was turned down by the Common Base Conference ten years earlier. Very roughly, one can say that the BETA project was an attempt to generalize and refine the related notion of classes, records, types and procedures into one basic construct upon which a new programming language could eventually be designed and implemented. The effort proved successful, and the BETA team came up with a new construct called Super Pattern. Based on this highly general concept, a DELTA compiler was later developed at the University of AArhus. Source: Birger Moeller-Pedersen: 'How did SIMULA make us Think of BETA'. Talk presented at: 'SIMULA 1967-1992', Special Workshop at TOOLS'92, Dortmund Germany, 31 March, 1992, and interview with Kristen Nygaard: November 28, 1991.

[63]

Myhrhaug Bjoern: 'Proposal for string handling and input/output definition in SIMULA 67 Common Base. Preliminary presentation' January 1968. NCC publication No. 212.

[64]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 471

[65]

Letter from Ron Kerr to the author, 17 March 1993.

[66]

Interview Drude Berntsen, 6 November, 1991.

[67]

NTNF's annual review 1969, p. 69

[68]

The running of the UNIVAC 1107 was, in the second half of the 1960s, one of NCC's most important sources of income, and a cornerstone in the Centre's research activities. When the Research Council's decision was known this naturally gave rise to speculations concerning NCC's future, and rightfully so since there were strong reasons to believe that central forces within the Research Council wanted to shut down the entire Centre, and transfer it's operations to other NTNF institutes. In a reaction to this, NCC employees organized themselves and launched a counterattack on NTNF. The conflict reached its climax in January/ February 1970, after which NCC was reorganized and the situation returned to normal. Source: Interview with Sverre Spurkland,

[27]

November, 1991.

[69]

The account of the development of UNIVAC SIMULA is based on an interview with Sigurd Kubosch, 5 March, 1992, correspondence with Ron Kerr 1993 and SIMULA Newsletter: Vol. 1, No. 1, May 1973

[70]

Interview with Drude Berntsen, 6 November 1991, and 'Draft outline for a SIMULA 67 agreement between UNIVAC and the Norwegian Computing Centre', September 1969.

[71]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 470.

[72]

Interview with Jacob Palme, 19 August, 1992, and Jacob Palme: 'Are Simulation Languages Convenient for Military Simulations?'. Research Institute for National Defence, Operations Research Centre Sweden, April 1968.

[73]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 475.

[74]

Karel Babcicky: 'The Stone Age SIMULA'. Talk presented at: 'SIMULA 1967-1992', Special Workshop at TOOLS'92, Dortmund Germany, 31 March, 1992

[75]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., p. 475.

[76]

Karel Babcicky: 'The Stone Age SIMULA'. Talk presented at; 'SIMULA 1967-1992', Special Workshop at TOOLS'92, Dortmund Germany, 31 March. 1992.

[77]

'Agreement on implementation of the SIMULA 67 language between Control Data A/S Norway and the Norwegian Computing Centre'. Oslo 23 May, 1967. NCC

[78]

SHAPE is an abbreviation for: Supreme Headquarters Allied Powers Europe.

[79]

Nygaard K. and Dahl O.J: 'The Development of the SIMULA Languages', Wexelblatt (ed.), Op.cit., pp. 473 - 474.

[80]

Drude Berntsen: 'Welcoming Speech', in Proceedings of the I. SIMULA Users' Conference. Oslo, September 24 - 25, 1973.

[81]

The following account, describing the development of the Swedish DEC-10 SIMULA compiler, is based upon an interview with Jacob Palme, 19 August 1992.

[82]

SIMULA Newsletter, Vol. 2, No. 3, August 1974.

[83]

DEC System-10 SIMULA Gazette, Vol. 1, No. 2, August 1975.

[84]

Kristen Nygaard: 'Constructing SIMULA - Cooperation and War'. Talk presented at: 'SIMULA 1967-1992', Special Workshop at TOOLS'92, Dortmund Germany, March 31, 1992, and interview with Kristen Nygaard:

[28]

November, 1991.

[85]

Interview with Drude Berntsen: 6 November, 1991.

[86]

Kristen Nygaard: 'Constructing SIMULA - Cooperation and War'. Talk presented at: 'SIMULA 1967-1992', Special Workshop at TOOLS'92, Dortmund Germany, March 31, 1992, and interview with Kristen Nygaard:

[28]

November, 1991.

[87]

Drude Berntsen: 'Welcoming Speech', in Proceedings of the I. SIMULA Users' Conference. Oslo, 24-25 September 1973. Among the largest users known in 1973 we find: The Norwegian Defense Research Establishment, the Swedish Research Institute of National Defence, the Finnish State Computing Center and Broken Hill Proprietary Co., Ltd. in Australia. In addition to these major institutions, a number of European universities were also known to use the language for educational purposes.

[88]

The SIMULA Standards Group was formed after the Common Base Conference in 1967. It consisted of one representative from each of the SIMULA implementation teams, plus two representatives from the Norwegian Computing Centre. An important part of their task was to guard the SIMULA 67 standard against the undesirable flourishing of dialects experienced in so many other languages. In this respect their efforts must be regarded as quite successful since the SIMULA 67 standard remained very much on track throughout the period and indeed up to the very present.

[89]

When talking about the ASU it would be wrong not to mention the 'Simulady' herself, Mrs. Eileen Schreiner. As secretary of the ASU from 1973 to 1989, and treasurer and Newsletter editor to the present (1993), Mrs. Schreiner has been a thread of continuity in the SIMULA community and in many respects SIMULA's staunchest champion.

[90]

SIMULA Newsletter: Vol. 2, No. 3, August 1974, p. 3. As of August 1974 the following countries were represented in ASU; Australia, Austria, Belgium, Britain, Czechoslovakia, Denmark, Finland, France, Germany, Hong Kong, Hungary, Israel, Italy, New Zealand, the Netherlands, Norway, Poland, South Africa, Spain, Switzerland, and the United States. In addition to this one must also take into account the SIMULA activity in the then Soviet Union, which in many ways constituted an ambiance of its own, isolated from the organizational framework of the ASU.

[91]

For interested readers I refer to Langdon Winner. 'Do artifacts have politics' in Donald MacKenzie and Judy Wajcman (eds.) The Social Shaping of Technology. Milton Keynes: Open University Press, 1985.

[92]

The following draws on an interview with Kristen Nygaard 28 November 1991.

[93]

Buxton (1968, pp. 210-211).

[94]

In spite of these good intentions, however, it is interesting to note that SIMULA never became an easy language to learn and use. Most people found it extremely difficult to adapt to the SIMULA way of thinking and Bjarne Stroustrup, author of C++ by far the most popular SIMULA-like language in the 1990s, claims that for people who were not familiar with the key concepts, SIMULA was incomprehensible. In his opinion, this also, to a large extent, explains why the language never became wide-spread in use. Source: Interview with Bjarne Stroustrup, 22 April 1993.

[95]

Interview with Kristen Nygaard, 28 November 1991.

[96]

Ibid.

[97]

In Norwegian: Jern- og metallprosjektet.

[98]

The Computer Professionals for Social Responsibility is an organization of computer professionals concentrating on certain areas of the impact of computer technology on society. The alliance dates back to the fall of 1981 when several researchers in Palo Alto, California decided to do something about their concern regarding the close connection between computing and the nuclear arms race.

[99]

John M. Staudenmaier, S. J.: Technology's Storytellers - Reweaving the Human Fabric. Cambridge, Ma: The Society for the History of Technology and MIT Press, 1985. See also Wiebe E. Bijker, Thomas Hughes and Trevor Pinch (eds.): The Social Construction of Technological Systems - New Directions in the Sociology and History of Technology. Cambridge, Ma: MIT Press, 1987.