The WEIZAC Years

1954-1963

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The WEIZAC Years

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The WEIZAC Years WEIZmann Automatic Computer.

The first digital computer in Israel.

WEIZAC was built during the years 1954-1955, and operated until 1963.

It is an early example of successful technology transfer, with the design of von Neumann’s IAS machine moving from the Institute for Advanced Study to the Weizmann Institute.

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The IAS Machine - JOHNNIAC One of the first digital computers.

The IAS machine was built during the years 1946-1952, by von Neumann’s group at the Institute for Advanced Study (IAS), Princeton.

Designers of the IAS machine were required to make their plans available to several other government-funded projects.

This resulted in the construction of fifteen derivative (but incompatible) computers referred to as the "IAS machines".

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The “IAS Machines” ADIVAC (Argonne National Laboratory, 1953).

BESK, SMIL (Stockholm, 1953).

BESM (Moscow, 1953).

CYCLONE (Iowa State University, 1959).

ILLIAC (University of Illinois, 1952).

GEORGE (Argonne National Laboratory, 1957).

JOHNNIAC (Rand Corporation, Santa Monica, California, 1953).

MANIAC (Los Alamos National Laboratory, 1952).

MSUDC, MISTIC (Michigan State University).

ORACLE (Oak Ridge National Laboratory).

ORDVAC (Aberdeen Proving Ground, Maryland, 1951).

SILLIAC (University of Sydney, 1956).

WEIZAC (Weizmann Institute, Israel, 1955).

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Talk Outline Chaim L. Pekeris

Introduction

Physical Realization of WEIZAC

Software – Making the Hardware Usable

Scientific Computing on WEIZAC

Impact of the WEIZAC Years

Conclusions

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Chaim L. Pekeris (1908-1993)

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Born in Lithuania, 1908.

1929: B.Sc. in Mathematics and Meteorology, MIT.

1934: Ph.D. in Applied Mathematics and Geophysics, MIT.

1934-1941: Faculty member at MIT.

1941-1945: Division of War Research at Columbia University.

Chaim L. Pekeris

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1945: Asked by Dr. Chaim Weizmann to establish a department of Applied Mathematics at the Weizmann Institute. Pekeris negotiated to build a digital computer for the new department.

1946-1948: Member of the Institute for Advanced Studies in Princeton, working with von Neumann on computational methods for solving physical problems.

1950-1978: Chair of the Department of Applied Mathematics at the Weizmann Institute.

Died in Rehovot, 1993.

Chaim L. Pekeris

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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IntroductionIn July 1947, an advisory committee was established for the Applied Mathematics Department. Among its members were Albert Einstein and John von Neumann.

“Among the issues we discussed was a plan for building an electric computer at the institute, based on the computer JOHNNIAC which was then being designed by von Neumann’s group.

Einstein was hesitant (…) but von Neumann’s persuasive powers won Einstein over.

Dr. Weizmann assigned $50,000 for the computer project. It was one fifth of the Weizmann Institute’s total budget then.”

(Pekeris in Estrin, 1991)

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IntroductionIn one conversation, von Neumann was asked:

“What will that tiny country do with an electric computer?”

He then responded:

“Don’t worry about that problem. If nobodyelse uses the computer, Pekeris will use itfull time!”

John von Neumann

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IntroductionThe primary reason for building WEIZAC, as suggested by Pekeris, was to solve Laplace’s tidal equations for Earth’s oceans with realistic geographical boundaries.

Pekeris insisted, however, that the entire scientific community of Israel, including the Defense Ministry, should have access to WEIZAC.

In 1952, Gerald Estrin, a member of von Neumann’s group at the IAS, was chosen to lead the WEIZAC project.

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Gerald Estrin (1921- )

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Born in New York, 1921.

1951: Ph.D. in Electrical Engineering, University of Wisconsin, Madison.

1951-1956: Member of von Neumann’s group at the IAS, Princeton. After the completion of the IAS machine, Estrin directed the building of WEIZAC.

1956: Faculty member at UCLA.

1979-1982, 1985-1988: Chair of the Computer Science department at UCLA.

Has served on the board of governors of the Weizmann Institute since 1971.

Gerald Estrin

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“While traveling through England, the Netherlands, France and Italy we felt ourselves being transported further and further in history. Our arrival in Israel took us back to the birth of Western civilization.

(…) When we reached the Weizmann Institute, we found ourselves in an oasis. The grounds of the Weizmann Institute were absolutely beautiful! Flowers, grass and trees abounded.“

(Estrin, 1991)

Gerald Estrin

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“At a cocktail party at the Pekeris home, we met a number of the leading Israeli scientists from the Weizmann Institute, the Technion and the Hebrew University.

(…) Except for Pekeris, they thought it was ridiculous to build an electronic computer in Israel.”

(Estrin, 1991)

Gerald Estrin

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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Physical Realization of WEIZAC“We arrived in Israel with a complete set of drawings and parts lists.

Essentially no materials were available in Israel. As I look back now (…) if we had systematically laid out a detailed plan of execution (…) we would probably have aborted the project.”

(Estrin, 1991)

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Physical Realization of WEIZAC“My first order of business was hiring staff and then launching into a training process. (…) A group would have to be ready to complete, maintain and operate a production system after we left.”

(Estrin, 1991) A newspaper advertisement resulted in a number of

responses.

Almost all of the applicants had no records of prior education because those records had been destroyed in the Holocaust or in the emigration process.

However, within the technical community in Israel, everyone knew or knew about everybody else.

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Physical Realization of WEIZAC

Gerald and Thelma EstrinZvi RieselYesheyahu ZiegelMicha KedemDavid LoeweEphraim FreiAviezri FraenkelGeorge Eisler

Members of the WEIZAC group:

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Physical Realization of WEIZAC

WEIZAC is a digital computer operating on 40 bits words.

Control is asynchronous (a signal is generated calling for the next operation).

An instruction word contains two 20-bits orders; 12 bits are used to select addresses, and 8 bits - for the actual order.

Memory: 4096 words; 40 bit parallel access; access time – 10 ms.

The 1959 WEIZAC Manual reports:

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Physical Realization of WEIZAC Fixed-point arithmetic. A number word consists of a signed digit

and 39 number digits.

Addition: 40 ms.

Multiplication: 800 ms.

Division: 850 ms.

Input-Output: Punched paper tape, magnetic tape.

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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Software – Making the Hardware UsableAn early IAS report, “Planning and Coding of Problems for an Electrical Computing Instrument” (Goldstine & von Neumann, 1948) outlined the need for reusable routines and offered methods to partially automate the programming and coding.

By 1951, an extensive library of subroutines had been developed for the IAS machine.

However, the changes in order code bits and memory address range prevented programs, written in Princeton, from running directly on WEIZAC.

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Software – Making the Hardware UsableThe Weizmann Institute drew upon emigrants from the west to give them their first start in support of programming.

The WEIZAC project provided an opportunity for young mathematicians and engineers to move to Israel without sacrificing their professional careers.

In 1954, Pekeris invited Phillip Rabinowitz to join the Weizmann Institute.

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Phillip Rabinowitz 1948: M.S. in Mathematics, University of Pennsylvania.

1948: Whirlwind Computer Project, Numerical Analysis Group, MIT.

1951: Ph.D. in Mathematics, University of Pennsylvania.

1951-1955: National Bureau of Standards.

1955: Joins the Weizmann Institute.

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Phillip RabinowitzProf. Rabinowitz started writing utility programs for WEIZAC, and developed the technique for calling subroutines.

“(…) Every piece of code I found in WEIZAC was written by Pinny Rabinowitz.”

(Accad in Estrin, 1991)

During 1955-1957, he taught the first programming and numerical analysis courses in Israel.

Prof. Rabinowitz had a major impact on the kernel of programmers and users who later made mature computations in Israel possible.

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“If many subroutines are available to the programmer, his task in programming a particular problem is simplified.

Among the types of subroutines prepared are those for evaluation of trigonometric, hyperbolic, exponential, and logarithmic functions, real and complex matrix multiplication, root extraction, quadrature, polynomial evaluation, floating point binary arithmetic, and others.”

(Pekeris, Progress Report, 1955)

Software – Making the Hardware Usable

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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Most of the scientific computing on WEIZAC was done by Pekeris, who drove use of his computing instrument through 24-hour and 7-day weeks of computation.

Scientific Computing on WEIZAC

Pekeris followed the agenda to resolve “unsolved problems in classical physics”.

He concurrently attacked four problems: atomic spectroscopy, predicting the tides in the world oceans, terrestrial spectroscopy, and theoretical seismograms.

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“E. Schrodinger was able to solve his wave equation only in the case of the one-electron atom hydrogen. In the case of two-electron helium, the mathematical difficulties were so formidable that the precision achieved in the theoretical term-values lagged behind the measured values.

Atomic Spectroscopy

(…) Pekeris developed a new method for the solution of the wave equation in the case of two-electron atoms and obtained, on WEIZAC, term-values of an accuracy exceeding by far the experimental accuracy.”

(Greene in Estrin, 1991)

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In 1962, Pekeris discovered a misidentification of one of the spectral lines of the lithium atom.

Pekeris predicted where the correct line should be sought.

Later that year, Edlen and Toresson (University of Lund, Sweden), discovered the line in “perfect agreement with Pekeris’ theory”.

Atomic Spectroscopy

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Other Scientific Computing on WEIZAC J. Gillis: Numerical solutions of problems in hydrodynamics, and

random walk methods.

G. Schmidt: X-ray crystal structure.

P. Rabinowitz: Numerical analysis.

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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WEIZAC’s existence, its intense application to physical problems, and the people trained in digital hardware, software, and computational methods opened a market of concepts and practices outside the United States and Europe.

The success of WEIZAC led to the recognition of the need for computers and other digital technology in Israel.

Impact of the WEIZAC Years

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Impact of the WEIZAC Years In 1974 there were 391 electronic computers in Israel.

Computing time allocation: 39% accounting

23% research

19% administration

11% economic applications

8% other

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Impact of the WEIZAC YearsHowever, the WEIZAC project did not create this marketplace directly.

In fact, once WEIZAC was executing programs successfully, there was a great deal of hostility expressed towards Pekeris.

Pekeris did not put a welcome mat for others to come and use “his” machine.

After external users were frustrated in their attempts to get computing time, they demanded that such computing instruments should be brought to Israel.

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On December 29, 1963, WEIZAC stopped computing after having accumulated the following life record of computing time and on time (in hours):

Impact of the WEIZAC Years

Year Computing Time On Time1955 112 1121956 2275 30191957 3351 43381958 6860 80961959 7515 86201960 7396 88641961 7367 87001962 7015 87001963 4260 5308Total 46151 55757

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Construction of the first GOLEM started in April, 1962, and was completed in November, 1963.

The GOLEM Decades

WEIZAC GOLEM A GOLEM B

In Operation 1955-1963 1964-1974 1973-1983Memory capacity (words)

4096 32768 131072

Word size (bits) 40 75 64Arithmetic Fixed point Floating point Floating pointMultiplication time (microseconds)

800 8 0.8

Input/Output Paper type Punched cards Punched cardsMagnetic tape Line printer Line printer

Magnetic tapes Magnetic tapesDisk Disks

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Talk Outline Chaim L. Pekeris Introduction Physical Realization of WEIZAC Software – Making the Hardware Usable Scientific Computing on WEIZAC Impact of the WEIZAC Years Conclusions

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The WEIZAC project resulted in putting a then-powerful computational instrument in the hands of applied mathematicians, who were driven to take on very serious problems.

It succeeded in creating technical knowledge necessary for Israel to play a strong role in the information revolution.

Conclusions

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ConclusionsOn February 25, 1993, Pekeris fell on the stairs of his home in Rehovot and died from the trauma of his injuries.

On his burial tombstone, in Rehovot, the following was inscribed in Hebrew:

"Led and headed the state of Israel to the era of computers"

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References G. Estrin, “The WEIZAC Years (1954-1963)”, IEEE Annals of

the History of Computing, vol. 13, no. 4, pp. 317-339, 1991.

G. Freeman, “C.L. Pekeris - A Biographical Memoir”, National Academy of Sciences, Biographical Memoirs, vol. 85, 2004.