The WEIZAC Years 19541963

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The WEIZAC Years1954-1963
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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 Neumanns 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 Neumanns 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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Chaim L. Pekeris

• 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.

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Chaim L. Pekeris

• 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.

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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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Introduction
In 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 Neumanns group. Einstein
was hesitant () but von Neumanns persuasive
powers won Einstein over. Dr. Weizmann assigned
50,000 for the computer project. It was one
fifth of the Weizmann Institutes total budget
then. (Pekeris in Estrin, 1991)
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Introduction
In one conversation, von Neumann was asked What
will that tiny country do with an electric
computer? He then responded Dont worry about
that problem. If nobodyelse uses the computer,
Pekeris will use itfull time!
John von Neumann
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Introduction
The primary reason for building WEIZAC, as
suggested by Pekeris, was to solve Laplaces
tidal equations for Earths 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 Neumanns
group at the IAS, was chosen to lead the WEIZAC
project.
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Gerald Estrin (1921- )
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Gerald Estrin

• Born in New York, 1921.
• 1951 Ph.D. in Electrical Engineering, University
  of Wisconsin, Madison.
• 1951-1956 Member of von Neumanns 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.

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Gerald Estrin
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)
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Gerald Estrin
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)
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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
The 1959 WEIZAC Manual reports

• 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.

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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 Usable
An 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 Usable
The 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 Rabinowitz
Prof. 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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Software Making the Hardware Usable
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)
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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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Scientific Computing on WEIZAC
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.
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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Atomic Spectroscopy
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.
() 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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Atomic Spectroscopy
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.
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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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Impact of the WEIZAC Years

• WEIZACs 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.

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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 Years
However, 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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Impact of the WEIZAC Years
On December 29, 1963, WEIZAC stopped computing
after having accumulated the following life
record of computing time and on time (in hours)
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The GOLEM Decades
Construction of the first GOLEM started in April,
1962, and was completed in November, 1963.
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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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Conclusions

• 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.

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Conclusions
On 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.