DYNAMO (programming language)

<h2 id="beginnings">Beginnings</h2>
In 1958, Forrester unwittingly instigated DYNAMO's development when he asked an MIT staff programmer to compute needed solutions to some equations, for a <a href="/facts/Harvard_Business_Review/leWeeqyj">Harvard Business Review</a> paper he was writing about industrial dynamics.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a><a class="footnote-ref" id="fnref:12" href="#fn:12">12</a>
The programmer, Richard Bennett, chose to implement a system (SIMPLE - "Simulation of Industrial Management Problems with Lots of Equations") that took coded equations as symbolic input and computed solutions. SIMPLE became the proof-of-concept for DYNAMO: rather than have a specialist programmer "hard-code" a special-purpose solver in a general purpose programming language, users could specify a system's equations in a special simulation language and get simulation output from one program execution.

<h2 id="design-goals">Design goals</h2>
DYNAMO was designed to emphasize the following:

<ul><li>ease-of-use for the industrial dynamics modeling community (who were not assumed to be expert programmers);</li>
<li>immediate execution of the compiled model, without producing an intermediate object file; and</li>
<li>providing graphical output, with <a href="/facts/Line_printer/QyWwtNBJ">line printer</a> and <a href="/facts/Pen_plotter/PEQa8H4p">pen plotter</a> graphics.</li></ul>
Among the ways in which DYNAMO was above the standard of the time, it featured <a href="/facts/Dimensional_analysis/t6UskoCD">units checking</a> of numerical types and relatively clear error messages.

<h2 id="implementation">Implementation</h2>
The earliest versions were written in <a href="/facts/Assembly_language/7XuV0cla">assembly language</a> for the <a href="/facts/IBM_704/bKkwXYb3">IBM 704</a>, then for the <a href="/facts/IBM_709/N8RAWUTP">IBM 709</a> and <a href="/facts/IBM_7090/RpY2uI1k">IBM 7090</a>. DYNAMO II was written in AED-0, an extended version of <a href="/facts/Algol_60/QnpxUYQm">Algol 60</a>.<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a><a class="footnote-ref" id="fnref:14" href="#fn:14">14</a>
Dynamo II/F, in 1971, generated portable <a href="/facts/FORTRAN/m1KqjcMU">FORTRAN</a> code<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a>
and both Dynamo II/F and Dynamo III improved the system's portability by being written in FORTRAN.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a><a class="footnote-ref" id="fnref:17" href="#fn:17">17</a>
Originally designed for <a href="/facts/Batch_processing/hKY2rX3N">batch processing</a> on mainframe computers, it was made available on <a href="/facts/Minicomputers/g8hvpQxe">minicomputers</a> in the late 1970s,<a class="footnote-ref" id="fnref:18" href="#fn:18">18</a>
and became available as "micro-Dynamo" on personal computers in the early 1980s.<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a>
The language went through several revisions from DYNAMO II up to DYNAMO IV in 1983,<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a>

<h2 id="impact-and-issues">Impact and issues</h2>
Apart from its (indirectly felt) public impact in environmental issues raised by the controversy over Limits to Growth, DYNAMO was influential in the history of discrete-event simulation even though it was essentially a package for continuous simulation specified through <a href="/facts/Difference_equations/JolXC71M">difference equations</a>.<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a> It has been said by some to have opened opportunities for computer modelling even for users of relatively low mathematical sophistication.<a class="footnote-ref" id="fnref:22" href="#fn:22">22</a> On the other hand, it has also been criticized as weak precisely where mathematical sophistication should be required<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a><a class="footnote-ref" id="fnref:24" href="#fn:24">24</a> and for relying only on <a href="/facts/Euler_integration/7yF5B4z9">Euler integration</a>.<a class="footnote-ref" id="fnref:25" href="#fn:25">25</a>

<h2 id="notes">Notes</h2>

<h2 id="bibliography">Bibliography</h2>
<ul><li>Introduction to System Dynamics Modeling with Dynamo (1981), George P. Richardson; Alexander L. Pugh III, Pegasus Communications, <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 1-883823-43-9</li>
<li>Modeling the Environment: An Introduction To System Dynamics Modeling Of Environmental Systems (1999), Andrew Ford, Island Press, <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 1-55963-601-7
<ul><li>Appendix D: Dynamo</li></ul></li>
<li>"The Prophet of Unintended Consequences", Lawrence M. Fisher, strategy+business #40 Autumn 2005 <a href="http://www.strategy-business.com/media/file/sb40_05308.pdf">[3]</a></li>
<li>Corporate Planning and Policy Design: A System Dynamics Approach (1981), James M. Lyneis, (MIT Press/Wright-Allen Series in System Dynamics) <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 0-262-12083-6</li>
<li>Modeling for Learning Organizations (2000), John D.W. Morecroft, John D. Sterman; Productivity Press (System Dynamics Series) (Hardcover) <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 1-56327-250-4</li>
<li>Dynamics of growth in a finite world (1974), Dennis L. Meadows, Wright-Allen Press, <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 0-9600294-4-3
<ul><li>Appendix C: How to Read a DYNAMO Flow Diagram;</li>
<li>Appendix D: How to Read Dynamo Equations</li>
<li>Appendix E: How to Read a DYNAMO Graphical Output</li></ul></li>
<li>Computer-Assisted Theory Building: Modeling Dynamic Social Systems (1988), Dr. Robert Hanneman, Sage Publications, Inc., 0803929617</li>
<li>Computer Simulation in Management Science (1998), Michael Pidd, Wiley, <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 0-471-97931-7</li>
<li>Simulation for the social scientist (2005), G. Nigel Gilbert, Klaus G. Troitzsch, Open University Press, <a href="/facts/ISBN_(identifier)/15AdSPa9">ISBN</a> 0-335-21600-5</li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20110309023917/http://hopl.murdoch.edu.au/showlanguage.prx?exp=61&language=DYNAMO">DYNAMO</a> - excerpt from manual contains much more detailed history.</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Meadows, Donella; Randers, Jørgen; Meadows, Dennis (2004). The limits to growth: the 30-year update. Chelsea Green Pub. p. 285. ISBN 1-931498-51-2. <a href="1-931498-51-2" target="_blank">1-931498-51-2</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Taylor, Peter J. (2005). Unruly complexity: ecology, interpretation, engagement. University Of Chicago Press. ISBN 0-226-79036-3. <a href="0-226-79036-3" target="_blank">0-226-79036-3</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Karayanakis, Nicholas Mark (24 June 1993). Computer-assisted simulation of dynamic systems with block diagram languages. CRC Press. ISBN 0-8493-8971-2. <a href="0-8493-8971-2" target="_blank">0-8493-8971-2</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Swanson, Carl V.; Raymond J., Waldmann (September 1970). "A Simulation Model Of Economic Growth Dynamics". Journal of the American Planning Association. 36 (5). Routledge: Taylor & Francis Group: 314–322. doi:10.1080/01944367008977327. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">"Resume and brief autobiography for Phyllis Fox, for Wellesley College Class of 1944 Record Book" (PDF). SIAM history website. January 1974. <a href="http://history.siam.org/sup/Fox_resume_bio.pdf" target="_blank">http://history.siam.org/sup/Fox_resume_bio.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Michael J. Radzicki; Robert A. Taylor. Origin of System Dynamics. U.S. Department of Energy Office of Policy and International Affairs. Archived from the original on 2017-06-20. Retrieved 2011-09-23. {{cite book}}: |work= ignored (help) <a href="https://web.archive.org/web/20170620213227/http://www.systemdynamics.org/DL-IntroSysDyn/origin.htm" target="_blank">https://web.archive.org/web/20170620213227/http://www.systemdynamics.org/DL-IntroSysDyn/origin.htm</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">Haigh, Thomas (interviewer) (2005). "Phyllis Fox" (PDF). The History of Numerical Analysis and Scientific Computing Oral Histories. Society for Industrial and Applied Mathematics. Retrieved 12 May 2010. {{cite web}}: |first= has generic name (help) <a href="http://history.siam.org/oralhistories/fox.htm" target="_blank">http://history.siam.org/oralhistories/fox.htm</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">"D-Memos 0 - 499". System Dynamics Society. Archived from the original on 2017-10-23. Retrieved 2010-05-08. <a href="https://web.archive.org/web/20171023094520/http://www.systemdynamics.org/MITCollectionDmemos0-499.htm" target="_blank">https://web.archive.org/web/20171023094520/http://www.systemdynamics.org/MITCollectionDmemos0-499.htm</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">DYNAMO User's Manual. MIT Press. 1963. pp. 2–3. <a href="https://books.google.com/books?id=VXtbAAAAMAAJ" target="_blank">https://books.google.com/books?id=VXtbAAAAMAAJ</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Meadows, Donella; Randers, Jørgen; Meadows, Dennis (2004). The limits to growth: the 30-year update. Chelsea Green Pub. p. 285. ISBN 1-931498-51-2. <a href="1-931498-51-2" target="_blank">1-931498-51-2</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Forrester, J.W. (1961). Industrial Dynamics. Cambridge MA: MIT Press. ISBN 1-883823-36-6. {{cite book}}: ISBN / Date incompatibility (help) <a href="1-883823-36-6" target="_blank">1-883823-36-6</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">""The Beginning of System Dynamics," Jay W. Forrester" (PDF). Archived from the original (PDF) on 2010-04-14. Retrieved 2010-05-08. <a href="https://web.archive.org/web/20100414144101/http://sysdyn.clexchange.org/sdep/papers/D-4165-1.pdf" target="_blank">https://web.archive.org/web/20100414144101/http://sysdyn.clexchange.org/sdep/papers/D-4165-1.pdf</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Ross, D.T.; Ward, J.E. (May 1967), "Investigations in Computer-Aided Design for Numerically Controlled Production", Tech Report, Electronic Systems Laboratory, Electrical Engineering Department, MIT <a href="http://dspace.mit.edu/bitstream/handle/1721.1/755/FR-0351-19563962.pdf.txt?sequence=2" target="_blank">http://dspace.mit.edu/bitstream/handle/1721.1/755/FR-0351-19563962.pdf.txt?sequence=2</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Sammet, J.E. (Aug 1969). Programming Languages: History and Fundamentals. Prentice Hall. p. 651. ISBN 0-13-729988-5. <a href="0-13-729988-5" target="_blank">0-13-729988-5</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">"Proceedings of the Annual Pittsburgh Conference on Modeling and Simulation". University of Pittsburgh. School of Engineering: Instrument Society of America. Pittsburgh Section. 1975: 1270. ISSN 0198-0092. Retrieved 12 May 2010. {{cite journal}}: Cite journal requires |journal= (help) <a href="https://books.google.com/books?id=MwYqAQAAIAAJ&q=dynamo.ii+fortran" target="_blank">https://books.google.com/books?id=MwYqAQAAIAAJ&q=dynamo.ii+fortran</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">"Proceedings of the Annual Pittsburgh Conference on Modeling and Simulation". University of Pittsburgh. School of Engineering: Instrument Society of America. Pittsburgh Section. 1975: 1270. ISSN 0198-0092. Retrieved 12 May 2010. {{cite journal}}: Cite journal requires |journal= (help) <a href="https://books.google.com/books?id=MwYqAQAAIAAJ&q=dynamo.ii+fortran" target="_blank">https://books.google.com/books?id=MwYqAQAAIAAJ&q=dynamo.ii+fortran</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">Computer & Control Abstracts,
 Volume 11,
 Institute of Electrical and Electronics Engineers
 p.1591 <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18">"'Dynamo' Now on Minis". Computerworld. 5 Jun 1978. <a href="https://news.google.com/newspapers?id=9XkbAAAAIBAJ&pg=6221,5184477&dq=pugh-roberts+dynamo&hl=en" target="_blank">https://news.google.com/newspapers?id=9XkbAAAAIBAJ&pg=6221,5184477&dq=pugh-roberts+dynamo&hl=en</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19">Roberts, Nancy (September 1982). Introduction to computer simulation: the system dynamics approach. Addison-Wesley. ISBN 0-201-06414-6. <a href="0-201-06414-6" target="_blank">0-201-06414-6</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">DYNAMO User's Manual, Sixth Edition, ISBN 0-262-66052-0 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">"A History of Discrete Event Simulation Programming Languages", Richard E. Nance, TR 93-21, Dept. of Comp. Sci., Virginia Polytechnic Institute and State University (cross-listed as Systems Research Center report SRC 93-003), June 11, 1993 [1] <a href="http://eprints.cs.vt.edu/archive/00000363/01/TR-93-21.pdf" target="_blank">http://eprints.cs.vt.edu/archive/00000363/01/TR-93-21.pdf</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">The electronic oracle: computer models and social decisions (1985), Donella H. Meadows, Jenny M. Robinson, John Wiley & Sons Inc, ISBN 0-471-90558-5 <a href="/wiki/Donella_Meadows" target="_blank">/wiki/Donella_Meadows</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Taylor, Peter J. (2005). Unruly complexity: ecology, interpretation, engagement. University Of Chicago Press. ISBN 0-226-79036-3. <a href="0-226-79036-3" target="_blank">0-226-79036-3</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">"An interview with
Phyllis A. Fox", SIAM website oral history, p.26 [2]: "Besides the servo-mechanism approach, [Forrester] used extrapolation, which is notoriously problematic, and unstable. You know yourself that you can’t extrapolate forever. It doesn’t work." <a href="http://history.siam.org/pdfs2/Fox_final.pdf" target="_blank">http://history.siam.org/pdfs2/Fox_final.pdf</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">Karayanakis, Nicholas Mark (24 June 1993). Computer-assisted simulation of dynamic systems with block diagram languages. CRC Press. ISBN 0-8493-8971-2. <a href="0-8493-8971-2" target="_blank">0-8493-8971-2</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
</ol>

DYNAMO (programming language) open-in-new

DYNAMO (programming language)