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A Fujitsu FACOM 201 parametron computer in the Science Museum of the Tokyo University of Science Fujitsu FACOM 201 Parametron Computer - Ridai Museum of Modern Science, Tokyo - DSC07668.JPG
A Fujitsu FACOM 201 parametron computer in the Science Museum of the Tokyo University of Science

Parametron is a logic circuit element invented by Eiichi Goto in 1954. [1] The parametron is essentially a resonant circuit with a nonlinear reactive element which oscillates at half the driving frequency. [2] The oscillation can be made to represent a binary digit by the choice between two stationary phases π radians (180 degrees) apart. [3]

Digital electronics Electronic circuits that utilize digital signals

Digital electronics or digital (electronic) circuits are electronics that operate on digital signals. In contrast, analog circuits manipulate analog signals whose performance is more subject to manufacturing tolerance, signal attenuation and noise. Digital techniques are helpful because it is a lot easier to get an electronic device to switch into one of a number of known states than to accurately reproduce a continuous range of values.

Eiichi Goto was a Japanese computer scientist, the builder of one of the first general-purpose computers in Japan.

Parametrons were used in early Japanese computers from 1954 through the early 1960s. A prototype parametron-based computer, the PC-1, was built at the University of Tokyo in 1958. Parametrons were used in early Japanese computers due to being reliable and inexpensive but were ultimately surpassed by transistors due to differences in speed. [4]

Japan Constitutional monarchy in East Asia

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south.

A computer is a machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of operations, called programs. These programs enable computers to perform an extremely wide range of tasks. A "complete" computer including the hardware, the operating system, and peripheral equipment required and used for "full" operation can be referred to as a computer system. This term may as well be used for a group of computers that are connected and work together, in particular a computer network or computer cluster.

The Parametron Computer 1 (PC-1) was a binary, single-address computer developed at Professor Hidetosi Takahasi's Laboratory at the Department of Physics, University of Tokyo, and was one of the first general purpose computers that used parametron components and dual frequency magnetic-core memory. Construction started in September 1957 and was completed on March 26, 1958. The PC-1 was used at Takahasi's Laboratory for research related both to hardware and software and the researchers in the Faculty of Science also used it for scientific computing. The PC-1 was retired in May 1964.

See also

Quantum flux parametron

Invented by Eiichi Goto at the University of Tokyo, the Quantum Flux Parametron (QFP) is an improvement over his earlier parametron based digital logic technology. Unlike its predecessor, QFP uses superconducting Josephson junctions on integrated circuits to improve speed and energy efficiency enormously. In some applications, the complexity of the cryogenic cooling system required is negligible compared to the potential speed gains. While his design makes use of quantum principles, it is not a quantum computer technology, gaining speed only through higher clock speeds. Apart from the speed advantage over traditional CMOS integrated circuit design is that parametrons can be operated with zero energy loss, making reversible computing possible. Low energy use and heat generation is critical in supercomputer design, where thermal load per unit volume has become one of the main limiting factors.

The MUSASINO-1 was one of the earliest electronic digital computers built in Japan. Construction started at the Electrical Communication Laboratories of NTT at Musashino, Tokyo in 1952 and was completed in July 1957. The computer was used until July 1962. Saburo Muroga, a University of Illinois visiting scholar and member of the ILLIAC I team, returned to Japan and oversaw the construction of MUSASINO-1.

The magnetic amplifier is an electromagnetic device for amplifying electrical signals. The magnetic amplifier was invented early in the 20th century, and was used as an alternative to vacuum tube amplifiers where robustness and high current capacity were required. World War II Germany perfected this type of amplifier, and it was used in the V-2 rocket. The magnetic amplifier was most prominent in power control and low-frequency signal applications from 1947 to about 1957, when the transistor began to supplant it. The magnetic amplifier has now been largely superseded by the transistor-based amplifier, except in a few safety critical, high-reliability or extremely demanding applications. Combinations of transistor and mag-amp techniques are still used.

Related Research Articles

In electronics, a logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more binary inputs and produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device.

Relay electrical switch

A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.

Magnetic-core memory predominant form of random-access computer memory for 20 years between about 1955 and 1975

Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core.


The cryotron is a switch that operates using superconductivity. The cryotron works on the principle that magnetic fields destroy superconductivity. This simple device consists of two superconducting wires with different critical temperature (Tc). The cryotron was invented by Dudley Allen Buck of the Massachusetts Institute of Technology Lincoln Laboratory.

The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as the transistor and later the integrated circuit. By 1959 discrete transistors were considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Computer main memory slowly moved away from magnetic core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size and power consumption of computers.

In electronics, rapid single flux quantum (RSFQ) is a digital electronic device that uses superconducting devices, namely Josephson junctions, to process digital signals. In RSFQ logic, information is stored in the form of magnetic flux quanta and transferred in the form of Single Flux Quantum (SFQ) voltage pulses. RSFQ is one family of superconducting or SFQ logic. Others include Reciprocal Quantum Logic (RQL), ERSFQ – energy-efficient RSFQ version that does not use bias resistors, etc. Josephson junctions are the active elements for RSFQ electronics, just as transistors are the active elements for semiconductor electronics. RSFQ is a classical digital, not quantum computing, technology.

The Orion was a mid-range mainframe computer introduced by Ferranti in 1959 and installed for the first time in 1961. Ferranti positioned Orion to be their primary offering during the early 1960s, complementing their high-end Atlas and smaller systems like the Sirius and Argus. The Orion was based on a new type of logic circuit known as "Neuron" and included built-in multitasking support, one of the earliest commercial machines to do so.

Transistor computer computer built using discrete transistors

A transistor computer, now often called a second generation computer, is a computer which uses discrete transistors instead of vacuum tubes. The first generation of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky and unreliable. A second generation of computers, through the late 1950s and 1960s featured circuit boards filled with individual transistors and magnetic core memory. These machines remained the mainstream design into the late 1960s, when integrated circuits started appearing and led to the third-generation machines.

Digital protective relay

In utility and industrial electric power transmission and distribution systems, a digital protective relay is a computer-based system with software-based protection algorithms for the detection of electrical faults. Such relays are also termed as microprocessor type protective relays. They are functional replacements for electro-mechanical protective relays and may include many protection functions in one unit, as well as providing metering, communication, and self-test functions.

Ferranti's Sirius was a small business computer released in 1961. Designed to be used in smaller offices without a dedicated programming staff, the Sirius used decimal arithmetic instead of binary, supported Autocode to ease programming, was designed to fit behind a standard office desk, and ran on UK standard mains electricity with no need for cooling. It was also fairly slow, with instruction speeds around 4,000 operations per second, and had limited main memory based on delay lines, but as Ferranti pointed out, its price/performance ratio was difficult to beat.

HITAC is the designation for the majority of Hitachi large and midrange computer models spanning several decades. The HITAC 301, released in May 1958, was Hitachi's first fully transistorized computer model. Earlier Hitachi computers made use of semiconductors known as parametrons.

Switching circuit theory is the mathematical study of the properties of networks of idealized switches. Such networks may be strictly combinational logic, in which their output state is only a function of the present state of their inputs; or may also contain sequential elements, where the present state depends on the present state and past states; in that sense, sequential circuits are said to include "memory" of past states. An important class of sequential circuits are state machines. Switching circuit theory is applicable to the design of telephone systems, computers, and similar systems. Switching circuit theory provided the mathematical foundations and tools for digital system design in almost all areas of modern technology.

Magnetic logic is digital logic made using the non linear properties of wound ferrite cores. Magnetic logic represents 0 and 1 by magnetising cores clockwise or anticlockwise.

The memory cell is the fundamental building block of computer memory. The memory cell is an electronic circuit that stores one bit of binary information and it must be set to store a logic 1 and reset to store a logic 0. Its value is maintained/stored until it is changed by the set/reset process. The value in the memory cell can be accessed by reading it.

Vacuum tube computer computer using vacuum tubes instead of transistors (prevalent in 1950s)

A vacuum tube computer, now termed a first-generation computer, is a computer which uses vacuum tubes for logic circuitry. Although superseded by second generation, transistorized computers, vacuum tube computers continued to be built into the 1960s. These computers were mostly one-of-a-kind designs.


  1. Information Processing Society of Japan - Parametron
  2. "Parametron". The history of computing project 17 March 2010. Retrieved 15 February 2011.
  3. U.S. Patent and Trademark Office - Class 307, Electrical Transmission or Interconnection Systems - Subclass 402, Parametrons
  4. Rojas, Rául; Hashagen, Ulf (2002). The First Computers: History and Architectures. Cambridge, Massachusetts: MIT Press. p. 429. ISBN   0-262-68137-4.