WEIZAC

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The WEIZAC project was initiated by Prof. Chaim L. Pekeris, who worked at the IAS at the time von Neumann's IAS machine was being designed. Chaim Weizmann, Israel's future first president, asked Pekeris to establish the Department of Applied Mathematics at the Weizmann Institute, and Pekeris wanted to have a similar computer available there. Pekeris wanted it as means to solve Laplace’s tidal equations for the Earth's oceans, and also for the benefit of the entire scientific community of Israel, including the Defense Ministry.{{fact|date=December 2022}}

In July 1947, an advisory committee for the Applied Mathematics Department discussed the plan to build the computer. Among the committee's members were Albert Einstein, who did not find the idea reasonable, and John von Neumann, who supported it. In one conversation, von Neumann was asked: "What will that tiny country do with an electric computer?" He responded: "Don’t worry about that problem. If nobody else uses the computer, Pekeris will use it full time!"{{Cite book |last=Corry |first=Leo |url=https://www.google.co.il/books/edition/Chaim_L_Pekeris_and_the_Art_of_Applying/AXG7EAAAQBAJ?hl=iw&gbpv=1&pg=PA7&printsec=frontcover |title=Chaim L. Pekeris and the Art of Applying Mathematics with WEIZAC, 1955–1963 |last2=Leviathan |first2=Raya |date=2023-04-24 |publisher=Springer Nature |isbn=978-3-031-27125-0 |language=en}}

In the end, a decision was made to proceed with the plan. Chaim Weizmann assigned US$50,000 for the project ({{Inflation|US|50000|1947|fmt=eq}}), which was 20% of the Weizmann Institute total budget.{{Cite web |title=weizac |url=https://www.wisdom.weizmann.ac.il/weizac/weizac.html |access-date=2025-05-02 |website=www.wisdom.weizmann.ac.il}}

In 1952, Gerald Estrin, a research engineer from the von Neumann project, was chosen to lead the project. He came to Israel along with his wife, Thelma, who was an electrical engineer and also involved in the project. They brought with them schematics, but no parts. Estrin later commented: "As I look back now, if we had systematically laid out a detailed plan of execution we would probably have aborted the project." After arriving, Estrin's impression was that besides Pekeris, other Israeli scientists thought it is ridiculous to build a computer in Israel.{{fact|date=December 2022}}

To recruit skilled staff for the project, a newspaper advertisement was posted. Most of the applicants had no records of prior education because those were lost in the Holocaust or during immigration, but in Israel's budding technical community everyone knew or knew about everybody else. The WEIZAC project also provided an opportunity for mathematicians and engineers to move to Israel without sacrificing their professional careers.{{cite web |url=http://www.ieeeghn.org/wiki/index.php/Milestones:WEIZAC_Computer,_1955 |title=Milestones: WEIZAC Computer |work=IEEE |accessdate=2010-03-25 }}

WEIZAC was an asynchronous computer operating on 40-bit words. Instructions consisted of twenty bits: an eight-bit instruction code and twelve bits for addressing. Punched paper tape was used for I/O, and later, in 1958, magnetic tape. The memory was initially a magnetic drum containing 1,024 words which was later replaced with a much faster 4,096 word magnetic-core memory module.{{fact|date=December 2022}}

In 1961, the memory was further expanded with two additional 4,096 word modules.{{fact|date=December 2022}}

In late 1955, WEIZAC performed its first calculation.{{Cite book|url=https://books.google.com/books?id=lvc8AQAAIAAJ&q=1955|title=Scientific Activities|last=le-madaʻ|first=Mekhon Ṿaitsman|date=1962|publisher=The Institute|pages=19|language=en}} Subsequently, it was used to study problems like worldwide changes in tide, earthquakes, atomic spectroscopy, X-ray crystallography, random walk methods, numerical analysis, and other problems. The computer found out that there was an amphidromic point in the South Atlantic at which the tide does not change. It also numerically calculated the eigenvalues of a two-electron atom quantum system based on programming by Yigal Accad who put Pekeris' development of the relevant equations into machine code.{{cite journal |title=The 1958 Pekeris-Accad-WEIZAC Ground-Breaking Collaboration that Computed Ground States of Two-Electron Atoms (and its 2010 Redux) |first1=Christoph |last1=Koutschan |first2=Doron |last2=Zeilberger |journal=The Mathematical Intelligencer |volume=33 |issue=2 |pages=52–57 |date=2011 |doi=10.1007/s00283-010-9192-1 |arxiv=1006.0200 |s2cid=1212549 }} These results were later experimentally verified by the Brookhaven National Laboratory, confirming the correctness of Schrödinger's Equations.{{fact|date=December 2022}}

WEIZAC was kept constantly busy, and users (especially from other institutions) became increasingly frustrated with not being able to get computing time, and demanded more computers to become available. WEIZAC's success led to the recognition of the demand for computers and digital technology in Israel, and ultimately, provided the foundation for Israel's computer and technology industries.

Until 1961, WEIZAC was the only computer in the State of Israel. It operated until 29 December 1963 and was replaced by a commercially-built computer, a CDC 1604A. At the same time the institute's staff began constructing the locally designed GOLEM – based on the ILLIAC II architecture, but with several improvements which resulted in significantly-reduced volume and power consumption.{{fact|date=December 2022}}

On 5 December 2006, WEIZAC was recognized by the IEEE as a milestone in the history of electrical engineering and computing, and the team who built it was awarded the "WEIZAC Medal".Bogdanowicz, Anna (5 December 2006) [https://web.archive.org/web/20070715083222/http://www.ieee.org/portal/site/tionline/menuitem.130a3558587d56e8fb2275875bac26c8/index.jsp?&pName=institute_level1_article&TheCat=1008&article=tionline/legacy/inst2006/dec06/history.xml& Middle East's First Computer Named History Milestone]. IEEE. Retrieved 2010-03-25

{{reflist}}

• The WEIZAC Years (1954-1963), Gerald Estrin, IEEE Annals of the History of Computing, vol. 13, no. 4, pp. 317–339, Oct-Dec 1991. {{ISSN|1058-6180}}.

• {{cite book |title=WEIZAC: An Israeli Pioneering Adventure in Electronic Computing (1945–1963)|author=Corry, Leo, Raya Leviathan|publisher=New York: Springer Verlag|year=2019 |url=https://link.springer.com/book/10.1007/978-3-030-25734-7}}
• {{cite book |title=Chaim L. Pekeris and the Art of Applying Mathematics with WEIZAC (1955–1963)|author=Corry, Leo, Raya Leviathan|publisher=New York: Springer Verlag|year=2023}}

{{Commons category|WEIZAC}}

• [https://wis-wander.weizmann.ac.il/content/computer-studies Weizmann Institute Computer Studies] – With a historical overview including the WEIZAC.
• [http://www.ieeeghn.org/wiki/index.php/Milestones:List_of_IEEE_Milestones IEEE History Center: WEIZAC Computer, 1955]
• [http://googleblog.blogspot.co.il/2013/06/remembering-weizac-beginning-of.html Remembering WEIZAC: the beginning of computing in Israel], in Google's official blog
• [https://www.youtube.com/watch?v=I9QVx_fc4OY WEIZAC: Israel's first computer] – Prof. Aviezri Fraenkel recounts WEIZAC's beginning (video)

{{Mainframes}}

Category:IAS architecture computers

Category:Israeli inventions

Category:Science and technology in Israel

Category:Weizmann Institute of Science

Category:1950s computers