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Pierre:</div>
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Good to hear from you.</div>
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After my retirement I donated my books and papers to a number of libraries and archives -- most of which are closed right now. I will have to rely on my memory, which was never that good anyway. So with that caveat...</div>
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A crucial step toward real-time digital computation was initiated by Perry O. Crawford, and described in his Masters' Thesis at MIT. There is a Wikipedia entry on Crawford, which appears to look right, although I can't check. I met Crawford and discussed this
topic briefly when I was writing my dissertation, but unfortunately I was not far enough along in my work to understand the point that he was trying to make regarding his role in Whirlwind. </div>
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The best analysis of Crawford's role was done by Bernard O. Williams, in his PhD dissertation at the University of Kansas, "Computing with Electricity 1935-1945" (Univ. Kansas 1984). It is a shame that the dissertation was never published, but it is available
electronically from University Microfilms [sic], #85137830. </div>
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Best,</div>
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<span style="margin:0px;font-size:12pt;font-family:Calibri, Arial, Helvetica, sans-serif;color:black">Paul Ceruzzi</span></div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Members <members-bounces@lists.sigcis.org> on behalf of Paul N. Edwards <pedwards@stanford.edu><br>
<b>Sent:</b> Saturday, April 24, 2021 3:01 PM<br>
<b>To:</b> Guy Fedorkow <guy.fedorkow@gmail.com><br>
<b>Cc:</b> members <members@sigcis.org><br>
<b>Subject:</b> Re: [SIGCIS-Members] whirlwind, radar and real-time tracking</font>
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<p class="x_MsoNormal" style="line-height:12.0pt; background:#FFEB9C"><b><span style="font-size:9.0pt; font-family:"Calibri",sans-serif; color:#9C6500">External Email - Exercise Caution</span></b></p>
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<div class="" style="word-wrap:break-word; line-break:after-white-space">Guy, seconding Pierre’s good response and adding that in 1951, analog computers were still far faster than digital for most complex calculations, because they are inherently parallel processors.
Digital machines were also prone to *very* frequent failure. Most sensors were analog, too, providing no numerical readouts. Few control engineers would have even considered a digital computer for any real-time application until the second half of that decade,
and even then they were not the natural choice for most applications.
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<div class="">The early chapters of my book The Closed World: Computers and the Politics of Discourse in Cold War America (Cambridge, MA: MIT Press, 1996) cover SAGE and the surrounding computing landscape of the 1940s-1950s. </div>
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<div class="">Other resources on SAGE:</div>
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<div class="" style="margin:0px"><font face="Helvetica" color="#000000" class="" style="font-stretch:normal; line-height:normal">Everett, Robert R., Charles A. Zraket, and Herbert D. Benington. “Sage: A Data-Processing System for Air Defense.” Proceedings of
the Eastern Joint Computer Conference (1957): 339–45.</font></div>
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<div class="" style="margin:0px"><font face="Helvetica" color="#000000" class="" style="font-stretch:normal; line-height:normal">Redmond, Kent C. and Thomas M. Smith. Project Whirlwind: The History of a Pioneer Computer. Boston: Digital Press, 1980.</font></div>
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<div class="" style="margin:0px"><font face="Helvetica" color="#000000" class="" style="font-stretch:normal; line-height:normal">Valley, George E., Jr. “How the Sage Development Began.” Annals of the History of Computing 7, no. 3 (1985): 196–226.</font></div>
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<div class="" style="margin:0px"><font face="Helvetica" color="#000000" class="" style="font-stretch:normal; line-height:normal">Redmond, Kent C. and Thomas M. Smith. From Whirlwind to Mitre: The R&d Story of the Sage Air Defense Computer. Cambridge: MIT Press,
2000.</font></div>
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<div class="">Best,</div>
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<div class="">Paul Edwards</div>
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<blockquote type="cite" class="">
<div class="">On Apr 23, 2021, at 16:41, Guy Fedorkow <<a href="mailto:guy.fedorkow@gmail.com" class="">guy.fedorkow@gmail.com</a>> wrote:</div>
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<div class="">Greetings Colleagues,<br class="">
I've been working on restoring a 1951 Whirlwind program, written at MIT, used to demonstrate real-time tracking of aircraft with radar for the purposes of guiding an interception (the Cold War was in full flight in the 1950's). This work ultimately led to
the massive SAGE air defense network in the US.<br class="">
You can see some rather informal preliminary notes on the work at<br class="">
<a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.historia-mollimercium.com%2Fwhirlwind%2FWW-Track-while-Scan-Draft-Notes-v1.pdf&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809785399%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=0WQ8hyh5ATsF%2B%2BE%2BvkWue%2F2wLBg%2B%2B%2FoSGOMTmSv7qLc%3D&reserved=0" originalsrc="https://www.historia-mollimercium.com/whirlwind/WW-Track-while-Scan-Draft-Notes-v1.pdf" shash="wX+HkYIKdO1QBNhQZ3/iRCs8KPRcGd/LDvj9j6nfocb5RcBEHIp8K/kFKs9oObF702LlnZCj2hEZww51MZf6HvnvTs99ySqZffFu9zXy9GVj9DFmQY1LEE0ezJPtKFkZQvGmd25m9s6KVgxYKH4qDgjhH5qO1k3f7uwH9HSbrbA=" class="">https://www.historia-mollimercium.com/whirlwind/WW-Track-while-Scan-Draft-Notes-v1.pdf</a><br class="">
The program does work in simulation; you can see a four-minute video of the simulator running an intercept at<br class="">
<a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.historia-mollimercium.com%2Fwhirlwind%2FTrack-while-scan-Apr-23-2021.mp4&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809795402%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=cV93KhAIGLmT%2BUT9y1egrnE5j%2BfKOtvBqcsS6vlRKSI%3D&reserved=0" originalsrc="https://www.historia-mollimercium.com/whirlwind/Track-while-scan-Apr-23-2021.mp4" shash="ob9KPYyatQz0fSrsjCmvrFz3f20Uw+pGVxSkZFHcTiY4+mWf53v/m8zi0k7LYpgojuDSnDOmsUDmhOMT3kpWvg6Y/NCtbFWYSyjKlpUWpA5YgcRt0Jkeky3yNpx7daZpe2Z+NgPi6uhj9tPCSFDclz4PHK0/VYgOC/fVbkm+4HU=" class="">https://www.historia-mollimercium.com/whirlwind/Track-while-scan-Apr-23-2021.mp4</a><br class="">
Spoiler alerts: The original really did display moving dots on a CRT, but the graphics are "spartan" to say the least. And nothing in particular happens when the intercept actually happens.<br class="">
<br class="">
Would anyone know of contemporaneous work involving digital computers for either radar tracking or real-time computing around 1951? I think all the familiar digital computers from those years were used in applications where batch operation was perfectly
acceptable, e.g., computing ballistics tables.<br class="">
Innovations like this rarely occur in a complete vacuum, but I don't see references to any similar digital computing projects.<br class="">
If anyone has pointers, do let me know!<br class="">
Thanks<br class="">
Guy Fedorkow<br class="">
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<br class="">
_______________________________________________<br class="">
This email is relayed from members at sigcis.org, the email discussion list of SHOT SIGCIS. Opinions expressed here are those of the member posting and are not reviewed, edited, or endorsed by SIGCIS. The list archives are at http://lists.sigcis.org/pipermail/members-sigcis.org/
and you can change your subscription options at http://lists.sigcis.org/listinfo.cgi/members-sigcis.org</div>
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<div>________________________</div>
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<div class=""><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fprofiles.stanford.edu%2Fpaul-edwards&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809805390%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=4GA5PNaQpBQmvIqwMV2aVMgqk1%2FB0edLmymZP45ztyc%3D&reserved=0" originalsrc="https://profiles.stanford.edu/paul-edwards" shash="NAkmbXAn+Zarl4+nIEVJYUILZpSiZcnvMbSmCc8HUjw1Xjpw8edFm5niJf/q9T5p1TuGUyb+I6QSZ6ZGjYQhuwFv0sOQUR8s5s6Vuyr8zlr0NbXV+QAoA8YfJOHfKcO+vXMq/xr7Q7SgKLPAPn3FJdozEyPEns74NoMPxKMeHac=" class="">Paul
N. Edwards</a><br class="">
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<div class="">Director, <a href="https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fsts.stanford.edu%2F&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809805390%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=vbVq%2B%2BWaMOvkxI9QlRZ9oqz5EwDKPXwe6IgKdhkuyyc%3D&reserved=0" originalsrc="http://sts.stanford.edu/" shash="OZ8I1SsEgjLtKWp9gzxQ4GuqiFCotk2W+FC67tf1B8v4oi5+qD7Fpyec+PWZ2xoS2FShF914b09wWuFehVEl2HEVRtdHJD1P1iqKLnFWNVWnKvJXbalf5fwSnLiMJTJ/DhhtP8QEGDDluAVHB+MKrk3OzPynnydhEWQKrnIiTT8=" class="">Program
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<div class="">William J. Perry Fellow in International Security and Senior Research Scholar</div>
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<div class="">Stanford University<br class="">
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Professor of <a href="https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.si.umich.edu%2F&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809815385%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=04BwXKhlnISoFTXDVE9fSDloJI6gtXQO9rwBa%2FSycs0%3D&reserved=0" originalsrc="http://www.si.umich.edu/" shash="FPZSNQS0GAOFMzsOGKyHbuB5VWCkwGO2yfdc+aapWrgE3N0e6TcZUQ7tWW9t3mt1lNnXOfN1nuV3wwfbnj5d3bw93bN+XO7wxoym5hP3H691PufnEf/Lce4m34jI0FvLC5BaDTRihxfZ97j4UqRjdGl4txbTATO2hxLflaIGZQo=" class="">Information</a> and <a href="https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.lsa.umich.edu%2Fhistory%2F&data=04%7C01%7Cceruzzip%40si.edu%7Cac59e0d26dcb4e38456908d9075afd7a%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C1%7C637548909809825377%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=eODY1QmI023ZV27MGYjq27DHBr%2F4w6HFT1xRf4Ayt7s%3D&reserved=0" originalsrc="http://www.lsa.umich.edu/history/" shash="lzBO9MUEp7XWykfTGhSkHeDenFcb01YYCe+V+CGhHMBVUK3ZejL9Hezae2NFBdLLMLVwTyBvXdvXiBKJspjx3yuyZ0qDIRT3aBvPkJzpUMlGyJ4dg4JzvuA4IZgfs3t3Z7t0fUSyjeTQsoKi+88QeH/OEo9uBtXS1uDHbnBYttU=" class="">History</a> (Emeritus)</div>
<div class="">University of Michigan</div>
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