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The MADDIDA (Magnetic Drum
Digital Differential Analyzer
A digital differential analyzer (DDA), also sometimes called a digital integrating computer, is a digital implementation of a differential analyzer. The integrators in a DDA are implemented as accumulators, with the numeric result converted back ...
) was a special-purpose
digital computer
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These pro ...
used for solving systems of
ordinary differential equations
In mathematics, an ordinary differential equation (ODE) is a differential equation whose unknown(s) consists of one (or more) function(s) of one variable and involves the derivatives of those functions. The term ''ordinary'' is used in contrast w ...
. It was the first computer to represent
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s using voltage levels and whose entire logic was specified in
Boolean algebra
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values ''true'' and ''false'', usually denoted 1 and 0, whereas in e ...
.
Invented by
Floyd Steele, MADDIDA was developed at
Northrop Aircraft Corporation
Northrop Grumman Corporation is an American Multinational corporation, multinational Aerospace manufacturer, aerospace and Arms industry, defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one ...
between 1946 and 1949 to be used as a guidance system for the
Snark missile. No guidance system, however, resulted from the work on the MADDIDA, and rather it was used for aeronautical research. In 1952, the MADDIDA became the world's top-selling commercial digital computer (albeit a special-purpose machine), six units having been sold. (The general-purpose
UNIVAC I
The UNIVAC I (Universal Automatic Computer I) was the first general-purpose electronic digital computer design for business application produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the invento ...
delivered its seventh unit in 1954.)
Development
Development on the project began in March 1946 at
Northrop Corporation
Northrop Corporation was an American aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman. The company is known for its development of the flying wing design, most successfully the B-2 Spiri ...
with the goal of producing a subsonic cruise missile designated "MX-775", which came to be called the Snark. Northrop's parameters for this project were to create a guidance system that would allow a missile to hit a target at a distance of up to with a precision that would be better than the German "vengeance" weapons
V1 and
V2. However, the MADDIDA was never used in weaponry, and Northrop ultimately used a different analog computer as the guidance system for the Snark missile.
Part of the project parameters involved developing the first
digital data analyzer (DIDA).
Physicist
Floyd Steele, who had reportedly in 1946 already demonstrated a working DIDA before the press in 1946 in his Los Angeles home, was hired as conceptual leader of the design group. Steele developed the concept for the DIDA, which would entail implementing an
analog computer
An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In c ...
using only digital elements. When the decision was made to use magnetic
drum memory
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory.
For many early computers, drum memory formed the main working memory ...
(MAD) for the DIDA, the name was lengthened to MADDIDA (pronounced "Mad Ida").
In his design for MADDIDA, Steele was influenced by the analog computer invented in 1927 by
Vannevar Bush
Vannevar Bush ( ; March 11, 1890 – June 28, 1974) was an American engineer, inventor and science administrator, who during World War II headed the U.S. Office of Scientific Research and Development (OSRD), through which almost all wartime ...
, which had digital components. Another influence was
Lord Kelvin
William Thomson, 1st Baron Kelvin, (26 June 182417 December 1907) was a British mathematician, Mathematical physics, mathematical physicist and engineer born in Belfast. Professor of Natural Philosophy (Glasgow), Professor of Natural Philoso ...
's
tide-predicting machine
A tide-predicting machine was a special-purpose mechanical analog computer of the late 19th and early 20th centuries, constructed and set up to predict the ebb and flow of sea tides and the irregular variations in their heights – which chan ...
, an analog computer completed in 1873.
Steele hired Donald Eckdahl, Hrant (Harold) Sarkinssian, and Richard Sprague to work on the MADDIDA's
germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors s ...
diode logic
Diode logic (DL), or diode-resistor logic (DRL), is the construction of Boolean logic gates from diodes. Diode logic was used extensively in the construction of early computers, where semiconductor diodes could replace bulky and costly active v ...
circuits and also to do magnetic recording. Together, this group developed the MADDIDA prototype between 1946 and 1949.
Design
The MADDIDA had 44
integrator
An integrator in measurement and control applications is an element whose output signal is the time integral of its input signal. It accumulates the input quantity over a defined time to produce a representative output.
Integration is an importan ...
s implemented using a
magnetic drum
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory.
For many early computers, drum memory formed the main working memory ...
with six storage tracks. The interconnections of the integrators were specified by writing an appropriate pattern of bits onto one of the tracks.
In contrast to the prior
ENIAC
ENIAC (; Electronic Numerical Integrator and Computer) was the first programmable, electronic, general-purpose digital computer, completed in 1945. There were other computers that had these features, but the ENIAC had all of them in one packa ...
and
UNIVAC I
The UNIVAC I (Universal Automatic Computer I) was the first general-purpose electronic digital computer design for business application produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the invento ...
computers, which used electrical pulses to represent
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s, the MADDIDA was the first computer to represent
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s using voltage levels. It was also the first computer whose entire logic was specified in
Boolean algebra
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values ''true'' and ''false'', usually denoted 1 and 0, whereas in e ...
. These features were an advancement from earlier
digital computers
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These programs ...
that still had analog circuitry components.
The original MADDIDA prototype is now part of the collection at the
Computer History Museum
The Computer History Museum (CHM) is a museum of computer history, located in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the information age, and explores the computing revolution and its impact on ...
in Mountain View, California.
Distribution
Ultimately, the MADDIDA was never used in weaponry. Northrop ended up using a different analog computing system to guide the Snark missile, a system that was so dubious that many missiles were lost. A missile launched in 1956 went so far off course that it landed in north-eastern Brazil and was not found until 1983. Many of those connected with the program commented in jest "That the Caribbean was full of 'Snark infested waters'".
After the MADDIDA design team left Northrop in 1950, another team, which included
Max Palevsky Max Palevsky (July 24, 1924 – May 5, 2010) was an American art collector, venture capitalist, philanthropist, and computer technology pioneer. He was known as a member of the Malibu Mafia – a group of wealthy American Jewish men who donat ...
, was hired to duplicate the machine for commercial distribution. By the end of 1952, six MADDIDAs had been delivered and installed, making it the bestselling commercial digital computer in the world at the time. One of the six was sold to the
Navy Electronics Laboratory
The U.S. Navy Electronics Laboratory (''NEL'') was created in 1945, with consolidation of the naval radio station, radar operators training school, and radio security activity of the Navy Radio and Sound Lab (NRSL) and its wartime partner, the U ...
(see above photo).
Aftermath
While developing the MADDIDA, the design team came to realize that a
digital differential analyzer
A digital differential analyzer (DDA), also sometimes called a digital integrating computer, is a digital implementation of a differential analyzer. The integrators in a DDA are implemented as accumulators, with the numeric result converted back ...
could be run on a general-purpose digital computer through the use of an appropriate
problem-oriented language (POL), such as
Dynamo
file:DynamoElectricMachinesEndViewPartlySection USP284110.png, "Dynamo Electric Machine" (end view, partly section, )
A dynamo is an electrical generator that creates direct current using a commutator (electric), commutator. Dynamos were the f ...
. A year after the first MADDIDA was demonstrated, Steele and the MADDIDA design team left Northrop, along with
Irving S. Reed, in order to develop general-purpose computers. On July 16, 1950, they formed the
Computer Research Corporation (CRC), which in 1953 was sold to
NCR.
Max Palevsky Max Palevsky (July 24, 1924 – May 5, 2010) was an American art collector, venture capitalist, philanthropist, and computer technology pioneer. He was known as a member of the Malibu Mafia – a group of wealthy American Jewish men who donat ...
, who later worked with the MADDIDA duplication team at Northrop, drew influence from the MADDIDA's design in his work in 1952–1956 building the
Bendix G-15
The Bendix G-15 is a computer introduced in 1956 by the Bendix Corporation, Computer Division, Los Angeles, California. It is about and weighs about . The G-15 has a drum memory of 2,160 29-bit words, along with 20 words used for special purpos ...
, an early personal computer, for the
Bendix Corporation
Bendix Corporation is an American manufacturing and engineering company which, during various times in its existence, made automotive brake shoes and systems, vacuum tubes, aircraft brakes, aeronautical hydraulics and electric power systems, av ...
. In March 1957, Palevsky begin work at
Packard Bell
Packard Bell is a Dutch-registered computer manufacturing brand and subsidiary of Acer. Originally an American radio set manufacturer, Packard Bell Corporation, it was founded by Herbert A. Bell and Leon S. Packard in 1933. In 1986, Israeli in ...
, at a new affiliate of the company he started called Packard Bell Computer Corp. Palevsky continued gaining commercial support for digital computing, allowing design advancement to continue. He retired as Director and Chairman of the Executive Committee of
Xerox
Xerox Holdings Corporation (; also known simply as Xerox) is an American corporation that sells print and electronic document, digital document products and services in more than 160 countries. Xerox is headquartered in Norwalk, Connecticut (ha ...
in May 1972. While Xerox would eventually drop personal computing, the Xerox prototypes would influence
Steve Jobs
Steven Paul Jobs (February 24, 1955 – October 5, 2011) was an American entrepreneur, industrial designer, media proprietor, and investor. He was the co-founder, chairman, and CEO of Apple; the chairman and majority shareholder of Pixar; a ...
and
Steve Wozniak
Stephen Gary Wozniak (; born August 11, 1950), also known by his nickname "Woz", is an American electronics engineer, computer programmer, philanthropist, inventor, and technology entrepreneur. In 1976, with business partner Steve Jobs, he c ...
in their 1979 tour of the Xerox facility
[http://zurb.com/article/801/steve-jobs-and-xerox-the-truth-about-inno Steve Jobs and Xerox: The Truth About Innovation.]
See also
*
List of vacuum-tube computers
Vacuum-tube computers, now called first-generation computers, are programmable digital computers using vacuum-tube logic circuitry. They were preceded by systems using electromechanical relays and followed by systems built from discrete transis ...
Notes
References
* Ceruzzi, Paul E. (1989). "Beyond the Limits: Flight Enters the Computer Age" The MIT Press.
* Reilly, Edwin D. (2003).
"Milestones in Computer and Science History"', Greenwood Publishing Group.
* Ulmann, Bernd. (2013). "Analog Computing" De Gruyter Oldenbourg.
* Annals of the History of Computing. Volume 9, Number 3/4. 1988.
Computer History Museum, Artifact Catalog: MADDIDA (Magnetic Drum Digital Differential Analyzer)Computer History Museum, MADDIDA Customer Demonstration* Zaloga, Steven J. "Chapter 5." ''Target America: The Soviet Union and the Strategic Arms Race, 1945–1964''. New York: Presidio Press, 1993. .
External links
* {{Commons category-inline, Magnetic Drum Digital Differential Analyzer
MADDIDA (Magnetic Drum Digital Differential Analyzer) at the Computer History Museum* Milestones in Computer Science and Information Technology
Full Text Free at Google Books
History of computing hardware
Vacuum tube computers