Milestone-Proposal:Parametron, 1954
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Docket #:2025-07
This proposal has been submitted for review.
To the proposer’s knowledge, is this achievement subject to litigation? No
Is the achievement you are proposing more than 25 years old? Yes
Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes
Did the achievement provide a meaningful benefit for humanity? Yes
Was it of at least regional importance? Yes
Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes
Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes
Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes
Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes
Year or range of years in which the achievement occurred:
1954
Title of the proposed milestone:
Parametron, 1954
Plaque citation summarizing the achievement and its significance; if personal name(s) are included, such name(s) must follow the achievement itself in the citation wording: Text absolutely limited by plaque dimensions to 70 words; 60 is preferable for aesthetic reasons.
The parametron, a logic element using ferrite cores and parametric oscillation, was invented in 1954 by Eiichi Goto at the University of Tokyo. As Japan’s first university-built stored-program computer, the PC-1 used 4,200 parametrons and became the nation's fastest computer in 1958. The parametron’s low cost and electrical stability shaped Japan’s early computer development and scientific research, and nurtured the country's first generation of computer engineers.
200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.
Parametron, invented in 1954 by Eiichi Goto, a graduate student at the University of Tokyo, is a logic element leveraging ferrite cores and parametric excitation for reliable, low-cost logical operations. By encoding binary states (0/1) through the phase of oscillation in a resonant circuit, it provided a stable alternative to the expensive vacuum tubes and unreliable transistors of 1950s computing. This innovation enabled 'majority rule logic,' supporting diverse computational functions with remarkable efficiency.
Separately, Goto’s work on Parametron and his innovations such as the concurrent processing of two instructions, contributed to the PC-1, Japan’s first stored-program computer at a university, completed in 1958. Built with approximately 4,200 parametrons, the PC-1 was the nation’s fastest computer of that time, featuring an arithmetic unit with high-speed carry propagation, a pioneering AC-driven magnetic core memory with non-destructive reading and error correction for access, alongside interrupt-driven multitasking and concurrent execution of two instructions for enhanced speed. This breakthrough democratized electronic computing for natural science researchers across Japanese universities, who depended on it as a free resource.
Though overtaken by transistor advancements in the 1960s, the parametron’s influence persisted. It jumpstarted Japan’s computing infrastructure and fueled early scientific research, securing its place in technological history. This invention highlights how creative design can overcome practical limitations, leaving a lasting legacy in computing evolution.
IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.
IEEE Computer Society
In what IEEE section(s) does it reside?
IEEE Tokyo Section
IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:
IEEE Organizational Unit(s) paying for milestone plaque(s):
Unit: IEEE Tokyo Section
Senior Officer Name: Toshiro Hiramoto
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: IEEE Tokyo Section
Senior Officer Name: Toshiro Hiramoto
IEEE section(s) monitoring the plaque(s):
IEEE Section: IEEE Tokyo Section
IEEE Section Chair name: Toshiro Hiramoto
Milestone proposer(s):
Proposer name: Chiaki Ishikawa
Proposer email: Proposer's email masked to public
Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.
Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):
Science Gallery, 1st floor (ground floor) of Building 1, Faculty of Science, The University of Tokyo. Address; 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 Japan.
GPS coordinates; 35.7137465,139.7608399
Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.
Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. Building 1 of Faculty of Science, the University of Tokyo is where parametron was invented. There is now a space to display many discoveries made by the researchers there and this Milestone will be displayed there.
Are the original buildings extant?
No. The building was rebuilt about a few dozen years ago.
Details of the plaque mounting:
It is placed on the wall of so-called "Science Gallery" where many displays related to science are placed. See: https://www.s.u-tokyo.ac.jp/en/gallery/
How is the site protected/secured, and in what ways is it accessible to the public?
Visitors can come to the Science Gallery without security check.
Who is the present owner of the site(s)?
Shin-ichi Ohkoshi Dean of School of Science, the University of Tokyo
What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include detailed support at the end of this section preceded by "Justification for Inclusion of Name(s)". (see section 6 of Milestone Guidelines)
Justification of name-in-citation
Eiichi Goto: Pioneer of Parametron Technology and Early Computers
Eiichi Goto (1931–2005), a Japanese scientist, invented the parametron in 1954 as a graduate student and spearheaded the development of the PC-1, the first fully programmable stored-program computer at a Japanese university to utilize this technology, completed in 1958. His innovations catalyzed advancements in Japan’s post-war computer industry, enhancing scientific research and industrial capabilities during a critical period of technological recovery.
Invention of the Parametron
In 1954, Eiichi Goto invented the parametron, a logic device leveraging nonlinear parametric oscillation with two ferrite cores [1–3, P1–P2]. Unlike the vacuum tube and early transistor circuits prevalent at the time, the parametron offered remarkable stability, requiring minimal maintenance compared to vacuum tubes with short life-time and costing significantly less than both vacuum tubes and nascent transistors. Its simplicity and reliability made it an ideal foundation for computer design. Early applications showcased its superior fault tolerance over competing technologies, such as vacuum tubes with relatively short-life-time, slow electromechanical relays, and unstable point-contact transistors. Driven by a desire to construct an electronic computer within the constrained budget of Takahasi’s laboratory at the University of Tokyo, Goto and his mentor, Takahasi, exhaustively explored affordable solutions; the parametron emerged as a breakthrough, laying a critical foundation for Japan’s post-war computing advancements.
Development of the PC-1 Parametron Computer
In 1957, Eiichi Goto led the development of the PC-1, a pioneering fully programmable stored-program computer powered by 4,200 parametrons [4–9, 11]. PC-1 began its operation on March 26, 1958.
Representing a significant advancement in post-war Japanese computing, the PC-1 outperformed emerging transistor-based systems in stability and featured a meticulously crafted instruction set, created by study of machines like the EDSAC ([12] The Preparation of Programs for an Electronic Digital Computer, M. V. Wilkes et al., 1951) by Goto, Takahasi and the rest of the team. The parametron’s inherent stability and multi-input capability enabled reliable, straightforward logic circuit design, exemplified by the 1959 implementation of an interrupt function—among the earliest of its kind—facilitating multitasking between the main program and I/O handling. Unlike the complex, maintenance-intensive vacuum tube computers of the era (vacuum tubes had relatively short lifetime compared with other circuit element), the PC-1 achieved high reliability with fewer components, low power consumption, and exceptional fault tolerance, ensuring sustained operation in a university laboratory environment.
Photo 1 Eiichi Goto and the PC-1 Parametron Computer (Source: Information Processing Society of Japan)
Photo 2 Eiichi Goto adjusting the memory section of Parametron
computer PC-1 (Source: Information Processing Society of Japan)
PC-1 was used by many scientific researchers after it became
operational in March 1958. It had profound impact on the Japanese
computer industry and scientific community. Details of the PC-1,
especially the software side, are thoroughly described in Eiichi
Wada's lecture materials from the Parametron Memorial Lecture held in
2008, commemorating 50 years since PC-1's implementation [11].
Libraries and calculation done on PC-1 are summarized in Appendix II.
Influence of Parametron Technology and Goto's Achievements
The parametron’s affordability, minimal maintenance, and operational stability swiftly captured Japanese industry attention following Goto’s initial presentation at a Japanese conference. Commercial entities soon adopted the technology, developing and marketing computers and calculators based on it (see Appendix I for examples). Some models sold more than 700 units back then.
At a time when vacuum tubes with the inherent short life cycle
demanded frequent upkeep and early transistors proved costly and
unreliable, the parametron filled a critical niche, earning Goto the
prestigious IRE Browder J. Thompson Memorial Prize in 1961 [A1] for
his seminal paper, “The Parametron, a Digital Computing Element Which
Utilizes Parametric Oscillation” [Proc. IRE, Aug. 1959]. This award
underscored the technology’s profound impression on both industry and
academia, cementing Goto’s reputation as a visionary innovator.
In Japan, he was awarded the prestigious Asahi Prize in 1959. This
was for his contribution to PC-1. [A2] The Asahi Prize (朝日賞, Asahi
Shō), established in 1929, is an prize presented by the Japanese
newspaper Asahi Shimbun and Asahi Shimbun Foundation to honor
individuals and groups that have made outstanding accomplishments in
the fields of arts and academics and have greatly contributed to the
development and progress of Japanese culture and society at
large. (from Wikipedia).
Conclusion
The parametron profoundly shaped Japan’s post-war computer industry, with its influence extending internationally through U.S. patents. As its sole inventor, Eiichi Goto elucidated its principles in his landmark IRE paper and led the Takahasi Laboratory team at the University of Tokyo in creating the PC-1. Given his pivotal role in this enduring technological achievement, Goto’s name merits inclusion in the IEEE Milestone citation, honoring his lasting legacy in computing history.
Historical Significance
Background
The parametron is a logic element that utilizes the parametric excitation phenomenon, leveraging the hysteresis characteristic of ferrite cores. It was invented in 1954 by Eiichi Goto, who was then a graduate student at the University of Tokyo's Graduate School of Science. In the 1950s, when computers were in their infancy, constructing a flip-flop in Japan cost around 1,000 yen for a vacuum tube and several thousand yen for a transistor. At the time, point-contact transistors were unreliable and unstable. The earliest junction-type transistors coexisted with point-contact transistors and were slow, so despite the instability, point-contact types were used for computers. At the Takahasi Laboratory of the University of Tokyo, where Goto studied, there was a keen interest in computational machines. Various devices, such as a computer using a rotary switch from a telephone exchange and a decimal computer using decatron tubes, were examined and manually simulated. (An earlier study of information storage devices [1], and [2] are examined in Appendix IV to give an overview of the kind of theoretical and experimental study that were done before the invention of Parametron.)
Eiichi Goto's knowledge of physics and applied
mathematics was invaluable during this time. Consideration was given
to using ferrite cores [3], which cost only 5 yen each, leading to the
concept of utilizing the parametric excitation phenomenon.
Consequently, the element was named the parametron.
Inexpensive ferrite core
Back then (pre 1954), a vacuum tube cost 1,000 Japanese yen, and a transistor 8,000 yen. A ferrite core was mere 5 yen. (See the following interview.) Goto mentioned the following in a magazine interview (in Japanese). The following English translation by the submitter is an excerpt from the interview in Japanese.: https://ascii.jp/elem/000/001/221/1221954/2/
——Why did you create parametron? At the time, there were no computers in Japan.*1 So we decided to make one at the Takahasi Laboratory at the University of Tokyo. But the university's research budget was not enough. At the time, vacuum tubes cost 1,000 yen each, and transistors cost 8,000 yen each. Also, vacuum tubes wear out quickly. Transistors were still unstable. In comparison, ferrite cores, which had long been familiar in, say radio circuit construction, cost just 5 yen each. So I thought, why not use ferrite cores as the material? Ferrite cores are a stable material, and since they are made of pottery, they don't break if you make them right the first time. The name “parametron” was given because it uses the principle of parametric excitation.
*1 The first Japanese vacuum tube stored program computer was built in 1956 (FUJIC). https://museum.ipsj.or.jp/en/computer/dawn/0010.html More on FUJIC in Appendix V for speed comparison.
The first Japanese transistor stored program computer was built also in 1956 (ETL Mark III): https://museum.ipsj.or.jp/en/computer/dawn/0011.html
UNIVAC 120 was the first commercial electronic computer installed in Japan in 1955.: https://museum.ipsj.or.jp/heritage/UNIVAC120.html
So, as Goto mentioned "There were no electronic computers in Japan" before 1954. Note: The submitter thinks Goto's recollection of 1,000 yen is a ballpark figure. But the two order of magnitude difference (factor of 200) is enough to show the cost merit of using ferrite cores.
A typical single parametric logic element used three cores (one larger
core was added to merge the signals from input wires from multiple sources) , one
capacitor and a resistor. Three such units were combined to create a
circuit element to pass logic signal to the next parametron unit.
Such a combination would NOT reach the price of a single vacuum tube
alone. And the vacuum tube circuit also requires capacitors and
resisters to boot. The difference of 1,000 Yen and 5 yen of main component is
large.
Vacuum tubes and transistors were expensive, and ferrite cores were
dirt cheap is the perception of Goto and others.
Structure and Principle of Parametrons
Two donut-shaped ferrite cores were each wound with a wire of the same number of turns. Two cores were required to cancel the original oscillation of the excitation (the wire turns for two cores were configured in opposite directions.)
Figure 1 Parametron (Source: Information Processing Society of Japan)
When the resonant frequency of the circuit, composed of ferrite cores
and parallel-connected capacitors, is frequency (f/2, f/2), then we apply
external oscillation of frequency (f, f) to the ferrite core.
These ferrite cores were connected in series. A single capacitor was connected
to form a resonant circuit. An excitation wire passed through the
core's hole, and when alternating current (precisely, a combination of
direct current that changed the inductance of the core and alternating current) flowed through it, the
magnetism of the ferrite core caused the resonant circuit to oscillate
due to parametric excitation.
Separate wires may be used for direct current and alternating current.
Oscillation at half the frequency of the original external vibration
is amplified and observed.
In Goto's parametron, information can be stored by correlating the logic
states 0 and 1 with the difference of the phase of induced oscillation.
(So parametron has the inherent capability to keep a bit of information.)
Parametric oscillation can be found in many systems. For example, to
move a swing, we use parametric oscillation. The length of the rope
or chain used to suspend the seat of a swing, or more precisely the
distance between the center of the mass of the body plus the seat
material and the horizontal bar from which the swing is suspended is a parameter of the
oscillation. By moving our position up and down, we can change this
distance of the center of the mass, thus changing the parameter of oscillation.
By moving our body up and down once during a swing one way
(this means we move our bodies TWICE up and down during the full one swing back
and forth), we can excite the natural frequency of swing.
The frequency of excitation (our body movement) is twice the frequency
of swing.
[Remarks] A matchstick is included in the photo for size comparison.
Photo 3 Parametron in PC-1 Computer (Source: Information Processing Society of Japan)
As described, in addition to the property of stabilizing into two
clearly distinct states, the parametron exhibits an amplification
effect where differences in the initial state during excitation
determine the phase outcome. This is used for logical operation using
majority logic.
The outputs from parametrons to another
parametron where a new oscillation was to be started
can decide the 0/1 state (the phase shift against the external
exciting frequency) by majority logic, i.e., analog addition of the signals.
With parametron that uses the phase of the oscillation to distinguish
0/1 value as digital signal, logical operations called "majority rule logic" can be performed.
Goto and others developed the full theory of this majority rule logic
based on parametron to design logic circuits.
(More about the theory of majority logic in the Obstacle to overcome section.)
While parametron was developed through theoretical and
experimental efforts, it was very fortunate that the very
first ferrite cores used in the first experiment for parametron was a copper-zinc type,
developed by Yogoro Kato and Takeshi Takei, which later turned out to be
verified to be best suited for parametrons among comparable ferrite
cores available at the time.
Although manganese-zinc and nickel-zinc ferrite have superior properties for other applications, copper-zinc ferrite proved best for parametrons [5] [Note 8].
To facilitate large-scale use in computing machines, smaller cores
were preferable for reduced power consumption, leading Tokyo Denki
Kagaku (today's TDK Corporation) to manufacture cores with a diameter of 4 mm. Later, the PC-2 used a "glasses-shaped core" specifically designed for parametrons.
Diagram: Parametron called as shaped like glasses marked with red rectangle.
4 φ core was the standard parametron initially.
2 φ core was used for memory.
Quoted from p.88 of Jiro Futami and Ryuji Shiozawa, "Parametron",
Hitachi Review, Feb 1960, vol 34. p.88, Figure 1 and Figure 2.
Parametron circuit
Parametrons are digital logic circuits that use nonlinear
elements. They were applied to the realization of logic and counting circuits.
They are characterized by high fault tolerance and low energy consumption in comparison to vacuum tubes.
Basic Structure and Operation of Parametrons
Parametrons are typically designed as two-terminal elements and are primarily constructed using capacitors and transformers. These elements transition between different "energy states," with the internal state changing in response to an external driving signal (input signal). Specifically, the amplitude and phase of the input signals, using by majority rule in the form of analog addition, determines the parametron to hold two stable states (0 and 1) distinguished by the phase difference to external excitation frequency signal and perform logical operations by transitioning between them.
The parametron circuit has the following characteristics:
(a) Nonlinear operation:
Parametrons respond non-linearly to external input signals. This property enables their use in logic circuits.
(b) Stability:
Parametrons are quite resistant to external noise and unstable signals, offering high fault tolerance.
(c) Low power consumption:
Parametrons consume very little power during operation, which made them particularly attractive in electronic circuits of the early days of computing. (This is RELATIVE to the power-hungry vacuum tube of that day. It consumed much more power than today's power-efficient devices, especially when one tries to run parametron at high speed. More about this in the Obstacle to overcome section.)
Counting Circuit Using Parametrons
As a prototype of later computer, a simple counting circuit was developed using parametrons. [3] When parametrons were used to create counting circuits, the design focused on the following key features:
(a) Counting circuits:
Parametron-based counting circuits combine multiple parametron elements to implement counting.
(b) Digital logic circuits:
Parametrons can serve as basic logic gates (e.g., AND, OR, NOT), which can be combined to create more complex computational circuits, such as adders and multipliers. But do note that parametron operates on the majority rule logic, not on the simple Boolean algebra.
The success of the counting machine that used counting circuit based on parametron encouraged the people at Takahasi laboratory and thus the construction of fully programmable stored-program computer PC-1 began.
The Birth of Parametron Computer: PC-1
The PC-1 (Parametron Computer No.1) is a fully programmable stored-program computer for scientific computing, assembled in the Takahasi Laboratory, Faculty of Science, at the University of Tokyo. Using a total of 4,200 parametrons, production began in September 1957, and the first computation was performed on March 26, 1958.
Note: A stored program computer had been created at NTT's Musasino Laboratory using parametrons in March 1957. It was called MUSASINO-1, and had only 32 words memory initially. 32 words were not enough for meaningful software development. The memory was expanded to 256 words one year later about the time PC-1 began full operation. MUSASINO-1 was a handmade prototype and experienced many hardware failures. Thus, it caused significant maintenance burden. It was used only inside NTT's research unlike PC-1 which was used widely by researchers in and outside the University of Tokyo as explained later. In this manner, MUSASINO-1 could not have much impact outside NTT whereas PC-1 had a big impact on Japanese computer scene. (More information and links on this MUSASINO-1 and billing machine in Appendix I.)
[Remarks] Dr. Eiichi Goto (Left) and Prof. Hidetosi Takahasi (right) in front of Parametron computer PC-1
Photo 4 PC-1 Parametron Computer (Source: Information Processing Society of Japan)
[Remarks] A vacuum tube is included in the photo for size comparison.
Photo 5 Adder using parametron (Source: Information Processing Society
of Japan)
Subsequently, multiplication and division circuits were added, and
finer adjustments were made to each part. Materials such as
parametrons, exciters, and input/output devices were borrowed from the
following companies.:
- Toyo Soda Industries,
- the International Telegraph and Telephone Company (today's KDDI),
- the Parametron Research Institute,
- Japan Electronics Instruments, etc.
Additionally, measuring instruments were borrowed from the Telecommunications Research Laboratory of the Nippon Telegraph and Telephone Public Corporation, and some were purchased with the Asahi Science Grant.
It took a total of about 300 person-days to assemble the computer,
with the parametron circuit wired by a worker experienced in wiring
relays at Fuji Tsushinki (today's FUJITSU). The assembly and
adjustment of the magnetic core memory device were performed by staff
from Tokyo Denki Kagaku (Today's TDK Corporation).
The parametrons used in the PC-1 were of the early type, produced at
different times and with irregular characteristics. Despite the
challenge of assembling all circuits by hand in a university
laboratory, there were no significant failures in 1958, except for
issues with the exciter and the input/output device that used vacuum
tubes.
Notably, the AC magnetic core memory device was surprisingly stable
and reliable in comparison to similar devices. One reason for this
stability was that, despite using 41 vacuum tubes in total, the main
memory system adopted a circuit that applied error-correcting code to
its operation, ensuring functionality even if one vacuum tube failed.
The performance figures of the PC-1 is detailed in the attached table.
It used a binary representation internally. (Note that there were
transistor-based computers that still used decimal digits
representation internally at the time.) PC-1 was a fully programmable
stored-program computer with fixed-point arithmetic only.
Wide Usage for Scientific Research and Training
In 1958, PC-1 was the fastest computer in Japan and the only electronic computer available to researchers at the University of Tokyo. Thus it was used frequently by the researchers there and from other universities.
In 1958, the PC-1 was operated for 9-12 hours a day, with 5 hours dedicated to various numerical calculations for the Faculty of Science at the University of Tokyo. The remaining time was used for program research in the Takahasi Laboratory. From October 1958, about 10 hours per week were devoted to practical training for students.
Considering that PC-1 was maintained by graduate students at Takahasi
laboratory, being able to run for close to half a day each day was a
remarkable achievement showing the stability of parametron-based digital circuit.
In addition to using parametrons, the PC-1 had the following features [5]:
Table 1 PC-1 and planned PC-2 Features
The characteristics of PC-2 (eventually built in 1960) in the table were according to the first design plan drafted in 1958. [5]
High-Speed Memory Device: AC magnetic core memory
For PC-1, an alternating current (AC) magnetic core memory device was used, a method invented in the Takahasi laboratory. Alternating current means the use of AC signal to read the data stored in core as the direction of magnetization. It used non-destructive read method as opposed to the direct-current destructive read method common to the core memory device used elsewhere in the world at the time.
The use of AC current for reading made the output quite friendly to the input to parametron device because the read signal from the core memory device was an oscillation wave unlike the DC current reading method.
By finding excellent magnetic
material suitable for this method through the help of TDK and using a
address selection circuit that applied an
error-correcting code at runtime, the device achieved exceptional stability and
reliability. The storage device was relatively small and reported at
the symposium on electronic computer storage in the fall of 1957 and
the Annual Meeting of the Four Electrical Societies of Japan in May 1958.
Arithmetic Circuit
The arithmetic circuit employed a fast carry propagation circuit that handled carry separately. It was basically a carry lookahead circuit in today's parlance, but back then there were some variations, and serious research was going on. Goto et al came up with their own implementation. The carry lookahead logic of PC-1 took advantage of the majority rule logic of parametron. A parametron element in it accepted five inputs. To make sure the majority worked as expected by tuning the input signal levels, careful selection of the selection of ferrite cores of the parametrons that generated the output fed to the five input parametron was necessary. (Thanks to the comment from a reviewer.)
Additionally, a control system was adopted that simultaneously managed
ongoing calculations and those to be performed next. This was
basically a pipelining at a very shallow depth of two. This improved
the calculation speed of the parametron computer by 2 to 3 times
compared to systems not using these methods, without significantly
increasing the number of parametrons required. In 1958, the pipelining
and other concurrent operation methods were being studied in many
countries and could be applied to electronic computers using any type
of logic element, not just parametrons.
Interrupt
Later in 1959, an interrupt circuit was installed so that the event from
the attached tape reader "interrupted" the on-going execution of an instruction.
When this happens, further interrupt was prohibited by a flip-flop,
and then the next instruction address is saved into address 510, and a pre-installed
interrupt handler whose address is in address 511 is invoked
(actually basically control jumps to the address stored in 511).
In this manner, the pending input from tape reader could be handled,
e.g., put into a ring buffer that is accessed both by the main program
and the interrupt handler.
This is basically the operation called later multi-tasking.
PC-1 was one of the earliest computers to realize multi-tasking using interrupt.
Plan for PC-2
In 1958, Goto and others began planning to build a more powerful machine based on the experience and results of the PC-1. The machine was named PC-2. Although the computation and storage methods of the PC-2 were not substantially different from those of the PC-1, the plan was to increase memory capacity as shown in Table 1, provide a high-speed I/O device, and add a floating-point computing unit and an address translation mechanism.
This time, however, the construction was solely assigned to an external company.
PC-2 was completed in 1960: Funded by the Ministry of Education, it was jointly developed with Fujitsu. It was later commercialized as FACOM 202. (More information on this PC-2 and FACOM 202 in Appendix I.)
PC-2 was delivered to Takahasi laboratory PC-2 continued the PC-1's tradition of wide usage by scientific researchers from all over Japan. A commercial version of PC-2, FACOM 202, was delivered to the Institute of Solid State Physics of the University of Tokyo, and TOYOTA. At the Institute, it was used to calculate band energy of solid and contributed to the world class research. (There is a short description of how FACOM 202 was used at the Institute of Solid State Physics in the newsletter of the Institute, p. 17, No. 5, Vol 4, December 1964, in Japanese, available online at https://www.issp.u-tokyo.ac.jp/maincontents/docs/tayori/tayori04-5.pdf)
PC-1 as a research vehicle of parametron performed very well. It was
finally disassembled when its power unit was rented to an exhibit done
by physic students during an annual open house event at the University
of Tokyo in May 1964.
Historical Impact of Parametron Computer
The ability to build computers with a greatly reduced number of vacuum tubes and transistors led to the creation of many parametron-type computers in Japan at that time. Compared to relay-based systems, parametrons were faster and had no mechanical contacts that were the source of many failures, offering great advantages.
Despite the relatively short period of time while parametron enjoyed success, these computers were sold in the market. A detailed list of these commercial computers is in Appendix I. There were many. Certain model was a best seller of the time, selling more than 800 units in total.
Back in 1959 when the seminal paper of Goto [9] was published ("The Parametron, a Digital Computing Element Which Utilizes Parametric Oscillation", Proceedings of the IRE, Volume: 47, Issue: 8, pp. 1304 - 1316, August 1959), Goto mentioned the following. (Quote from the paper).
In 1954 the author discovered that a phenomenon called parametric oscillation, which had been known for many years, can be utilized to perform logical operations and memory functions, and gave the name "Parametron" to the new digital component made on this principle [1], [21]–[23].(Proposer's note: the reference numbers are original paper's.).
A digital computing circuit made of parametrons may consist only of capacitors, ferrite-core coils and resistors, while diodes and rectifiers may be dispensed with. The parametron, therefore, is considered to be extremely sturdy, stable, durable, and inexpensive. Owing to these advantages, intensive studies have started in several laboratories in Japan to apply parametrons to various digital systems. AT PRESENT, NEARLY HALF OF THE JAPANESE ELECTRONIC COMPUTERS IN OPERATION USE PARAMETRONS FOR LOGICAL ELEMENTS. Further applications have been made to such devices as telegraphic equipment, telephone switching systems and numerical control of machine tools. (The EMPHASIS is by the proposer.)
However, the rapid performance improvements of junction transistors, which became mainstream shortly afterward, outpaced parametrons in operating frequency. Transistors had broader applications, such as in radios and analog circuits also, while parametrons were dedicated to the use as logic elements. Thus the investment on R&D of transistors far outweighed that of parametron. By the mid-1960s, parametrons were almost entirely replaced by transistors and fell into disuse.
Nurturing the new generation of computer engineers and users
Parametron's impact was also human resources and science computing. Many future computer scientists/engineers were born among the early users of PC-1, the stored-program parametron computer at the University of Tokyo. Many of them were graduate students. Also, many researchers created scientific computation library routines.
Only very sketchy information in the early days of PC-1 computing remain today. But there is a record of a seminar on programming organized by the Japanese Society of Physics in 1959. That used PC-1 as the target computer to write programs.
The timetable of the seminar in 1959. Quoted from "TOYOTA and parametron electronic computer FACOM 202", Yoshihiro Ishibashi, available online at: https://www.toyotariken.jp/_/media/page/about/research-report/pdf/Toyota-Report_No.77_62.pdf
The seminar was held from Aug 31 to Sept 7 in 1959. Below the titles and speakers of the lectures are quoted. (from IIJLAB 2008, パラメトロン計算機 PC-1 1958-2008 パラメトロン計算機記念会, "Parametron computer PC-1 1958-2008" by Parametron computer anniversary committee in Japanese, https://www.iijlab.net/~ew/pc1/pc150th.pdf)
This shows the impact PC-1 had on Japanese academia, in this case to physical sciences.
The title of each lecture and the name of the lecturer is given below.
Introduction to Electronic Computing by Hidetosi Takahasi
Arithmetic Instructions for the Parametric Computer PC-1 by Eiichi Goto
Experience in using electronic calculators by Takehiko Shimanouchi
Applications to Geometric Optics, etc. by Bunji Okazaki
Application to Crystal Analysis by Yoshio Takeuchi
Numerical Analysis for Computers I (Linear Computation) by Shigeichi Moriguchi
Numerical Analysis for Computers II (Numerical Integration and Differential Equations) by Ayao Amemiya and Masataka Ariyama
How to make programs (flow charts and their examples) Yoshihiro Ishibashi
Application to Meteorology by Kikuro Miyakoda
Application to Fluid Mechanics by Isao Imai
How to program (how to use subroutines) by Takashi Soma
How to make programs (how to make tapes using R0 R1) by Keisuke Nakagawa
Electronic Computing in Universities I by Yonezo Morino
Electronic Computing in Universities II by Mitsuro Omori and Shigetoshi Katsura
Monte Carlo Method by Yoichi Fujimoto and Eiichi Goto
Applications to Quantum Mechanics by Masao Kotani
Applications in OR and Control Engineering by Koh Hosaka
How to find errors in programs by Eiiti Wada
Future computers and programming by Hidetosi Takahasi
Panel Discussion "Current Status and Future of Computers"
Chair: Takahiko Yamamouchi
Panelists Takashi Isobe (The Univ. of Tokyo), Koh Hosaka
(Technical Research Institute of the Japanese National Railways),
Hidetosi Takahasi (The Univ. of Tokyo), Shigeichi Moriguchi (The
Univ. of Tokyo), Masao Kotani (The Univ. of Tokyo), Hiroshi Wada
(Electro-technical Laboratory, ETL), Zen'ichi Kiyasu (NTT),
Takeshi Kayano (NTT)
Many names in the list of lectures would hold important positions
later in the computer industry in Japan or academia, both in software
and hardware area. PC-1's legacy lived on after parametron fell into
disuse.
The list of available routines and the type of calculations
performed on PC-1 is in Appendix II.
Popular Culture
When many people in the first generation of computer industry and in academia in Japan got their first taste in programming on parametron-based computers, it had left its imprint on education as you can see from the number of parametron computers still displayed at many education institutes and research facilities. (See Appendix I for such examples.).
Parametron also left a legacy or urban-legend memory on the mind of early electronics engineers.
Thus, it has even popped up in very popular comic lately.
"Dr. Stone" is a very popular Japanese comic (and turned into animation) with total circulation more than 18 million copies. (See Wikipedia: https://en.wikipedia.org/wiki/Dr._Stone )
The story is an SF-like one.: A mysterious catastrophe petrified all human beings and after a few thousand years, one of them somehow was revived to life and investigated the situation, and tried to re-create the human civilization with some partners he found.
Along the way, they had to create many instruments that one took for granted in every day life. During the course of urban planning, the characters wished for a calculator and computer. Vacuum tubes are way off their manufacturing skill to say nothing of the semiconductors that required purified semiconductor crystals (in the SF story timeline, semiconductor would be available in 10 years time, but the calculators are wanted NOW).
Then, parametron to the rescue (!). Ferrite cores could be manufactured by heating and pressing metal powder. Thus in the comic, 0.2 million parametron cores were going to be created using such crude method so that they could be used to create computers and calculators.
The above drawing is from the 206th installment of Dr. Stone (August 2021).
You can see the original pages from officially sanctioned sources such
as the following (in Japanese). https://www.mangajikan.com/chapter-104565.html
Note: The above drawing is quoted as fair use for academic purposes of the copyright material.
(See Shueisha publishing's copyright stance.
https://faq.shueisha.co.jp/faq/show/32?category_id=8&site_domain=default )
Although the proposer thinks there is a slight abnormality in the
enlarged core shape in the drawing (upper-left), this is a great way to teach
parametron existed to the youth today, and tell the general audience
that it is still viable as Adiabatic Quantum-Flux-Parametron (AQFP) in
21st century.
What obstacles (technical, political, geographic) needed to be overcome?
Obstacles (Technical, Political, Geographic) Needed to Be Overcome
The parametron, invented by Dr. Eiichi Goto in 1954, is recognized as
a significant milestone in the history of logical device for electronic computing. This pioneering technology faced numerous obstacles on its path to success, spanning technical, political, and geographic challenges.
Technical Obstacles
Material Limitations
During the early 1950s, the materials available for electronic components were limited. The parametron, which relied on the parametric excitation of non-linear inductance to achieve switching, required high-quality inductors and capacitors. The scarcity of high-quality materials and the limitations in manufacturing technology posed significant challenges. Achieving the necessary precision and reliability in component fabrication was a major hurdle.
As Goto mentioned later, he was lucky to use the right ferrous material as far as the ferrite core, the essential part of his parametron device, was concerned. He picked up a ferrite core very suited to parametron his first experiment. Had he not used the particular material, the search for the right material alone may take a couple of years, thus missing the opportunity to fill in the gap between vacuum tube and transistor with very reliable parametron device.
Design Complexity
The initial physical design of parametron was intricate and required a deep understanding of non-linear dynamics and resonance phenomena. This complexity made the design and construction of practical parametron circuits challenging. Researchers had to overcome the difficulties of designing circuits that could maintain stability and reliability under varying operational conditions.
But, once the physical circuit was designed properly with well selected proper material, parametrons performed very reliably.
This was the key reason the stored-program computer built at a university laboratory operated so successfully without any dedicated operator. Serious breakdown of the PC-1 computer did not occur often, The graduate students and the researchers there helped the external science researchers who ran long-running computer programs. Programs could run for a few hours unattended on PC-1, which was a feat in itself in its time.
Another key challenge in parametron design was its reliance on
majority logic, which differed significantly from the binary Boolean
logic prevalent in electric/electronic circuit design at the time and
today. Boolean algebra, designed for binary AND, OR, and NOT
operations, was inadequate for majority logic circuits.
To address this, Goto and Takahasi developed a novel approach to majority logic for Parametron-based designs.
First, they introduced a graphical representation to visualize the majority logic employed in Parametron circuits, making the interaction of majority logic more visible. The interested readers are invited to read the Goto's seminal paper where the notation is explained.[9] It is a very interesting exercise to implement various logical operations using majority rule logic of parametron. A few examples are given (taken from [14]).
Figure - Majority rule circuit representation of Parametron
A circle stands for one parametron element. It can accept multiple input signals. The +/- in the circle indicates an input signal that is constantly set either to 1 (+), or 0 (-). The bar in the connection line stands for negation. In parametron, negation does not need a logic element. Reversing the direction of winding through the ferrite core achieves that.
The upper left is a Boolean AND operation. Since there is a constant 0 input (note the "-" in the circle), only when two other inputs are both 1s, the majority rule produces output 1, thus implementing Boolean AND operation.
The example at the middle in the left is boolean OR operation. Since there is a constant 1 input (note the "+" in the circle), if at least one of x or y is 1, the majority rule produces one as output, thus implementing Boolean OR operation.
The lower right is a full adder. x is a carry from
the addition of lower binary digits. The circuit produces the sum, 's', of x, y, and z,
and produces 'c', carry, that is needed to pass to the next higher bit
calculation.
Building on this, they systematically analyzed all possible three-input majority logic configurations, optimizing circuits to achieve desired outputs.
Their breakthrough was the classification of majority logic circuits into self-dual equivalence classes, which groups equivalent functions to reduce design complexity ([6], “Some Theorems Useful in Threshold Logic for Enumerating Boolean Functions,” E. Goto, H. Takahasi, IFIP Congress, 1962; see also “Classification of Ternary Logic Functions by Self-Dual Equivalence Classes,” T. Soma, T. Soma, 41st IEEE International Symposium on Multiple-Valued Logic, 2011. The latter is an extension of parametron to use three valued logic, using three different phases instead of two).
This classification provided critical insights for designing logic
circuits using Parametrons and other threshold logic devices. It
remains relevant today, enabling efficient designs for quantum flux
parametron (QFP) and its adiabatic version, AQFP, which have gained
significant attention, as discussed in the “Features” section.
Thermal Management
The operation of the parametron at fast speed involved significant energy dissipation, leading to heating issues. Effective thermal management was crucial to ensure the longevity and reliability of the Parametron circuits. Designing cooling mechanisms and optimizing the thermal performance of components were critical technical challenges.
In the case of the PC-1 computer mentioned in this submission, it did not push the speed limit much. Thus, this computer at the University of Tokyo, employing approximately 4200 parametrons did not suffer from catastrophic heat failure.
According to a memoir by Keisuke Nakagawa (in "パラメトロン計算機 PC-1 1958-2008 パラメトロン計算機記念会,", Parametron computer PC-1 1958-2008" by Parametron computer anniversary committee in Japanese, https://www.iijlab.net/~ew/pc1/pc150th.pdf), who was a graduate student at Takahasi laboratory where PC-1 was placed, "PC-1 came to be used by researchers of the Faculty of Science for their research. The computer time was made available even during night hours. PC-1, despite the meager 512 words storage (one word was 18 bits), allowed scientists to do variety of computations in many fields. PC-1 operated in a room without a special air conditioner for it. People opened windows during summer, but closed the windows with steam central heating running during winter. But PC-1 kept running demonstrating parametron's stability to the world. However, if PC-1 showed flaky behavior, available graduate students followed the predefined recover steps so that PC-1 ran again." (in submitter's translated summary from the original Japanese).
Mr. Nakagawa was a graduate student back then.
Integration with Existing Technology
The Parametron was a novel technology that needed to be integrated with existing computing systems and peripherals. Ensuring compatibility with the infrastructure of the time, including input/output devices and memory systems, required innovative solutions. Researchers had to bridge the gap between the new Parametron technology and the established electronic computing landscape.
These are the issues any new logic device technology faces, so not a particular obstacle specific to parametrons.
PC-1 computer that was built with parametron was connected to a paper tape
reader, and teletype writer device and so the interfaces with simple
I/O devices were available.
Miniaturization
Early electronic components were bulky, and miniaturizing the parametron circuits was a daunting task. Reducing the size of the parametron while maintaining its functionality and performance required advancements in component design and fabrication techniques. This miniaturization was essential for making the parametron commercially viable and practical for real-world applications.
Unfortunately, obviously, in the long run, there was no chance for ferrite core parametron to compete with the transistor in the miniaturization race.
However, later in the 1990s, miniaturized superconducting device was used
to create a parametron like
behavior, and is still a hot topic. (https://en.wikipedia.org/wiki/Quantum_flux_parametron,
Adiabatic Quantum-Flux-Parametron: A Tutorial Review
https://www.jstage.jst.go.jp/article/transele/E105.C/6/E105.C_2021SEP0003/_pdf/-char/en
Political Obstacles
Cold War Era: The development of the Parametron occurred during the
Cold War, a period marked by intense geopolitical tensions between the
Eastern and Western blocs. This political climate influenced research
priorities and funding allocation. Gaining support and resources for
parametron research in Japan, which was rebuilding its economy and
technology sector after World War II, was a significant challenge.
Funding and Resources
Securing funding for innovative research was a constant struggle in post-war Japan. Government and institutional support were limited, and researchers often had to rely on private industry partnerships and international collaborations. Convincing stakeholders of the potential benefits and applications of the Parametron required substantial effort and persuasion.
In [7] ("Some Important Computers of Japanese Design", IEEE Annals of the History of Computing, Vol.2, No.4, pp. 330-337. Oct.-Dec. 1980), Professor Hidetosi Takahasi remarked in its abstract to describe the era.: "we were on the verge of starvation in the ruin of our defeated country", and "We were starved for knowledge as well as for food". Such was the atmosphere of post-war Japan when parametron was invented.
Goto himself and the laboratory of Professor Takahasi back then was lucky to obtain a few big corporate backing after initial report of Goto on the principle and experimental result of parametron device caught the eyes and ears of the people of a big research laboratory, Musasino Laboratory of NTT, a large telephone operator Kokusai Denden (KDD), and others. This backing helped parametron take off.
Still the budget was small in comparison, say to MIT's: Goto mentioned the following in a magazine interview (in Japanese). The following English translation by the submitter is an excerpt from the interview in Japanese.: https://ascii.jp/elem/000/001/221/1221954/3/
——How was the reaction to the PC-1 parametron computer? “It wasn't that big a deal. *1 Overseas, there were already things like ENIAC and EDSAC ten years earlier. Also, the processing speed of the parametron was slower than that of transistor computers. The clock speed of transistor computers was 1 megahertz, whereas the parametron computer was at most 10 to 30 kilohertz. Much later, I became friends with McCarthy from MIT, and he told me, “The parametron is an interesting idea, but why did you make such a slow element?” He could say that out of ignorance, but our budget was only about one thousandth of MIT's *2. But I did feel a sense of achievement in having made computers available at the university at that time. Even though it only had 256 words of memory, lots of people came to use it. There weren't any other computers around at the time. *1: The submitter thinks Goto underrated PC-1 much as its creator because of his modesty and because he was too aware of the speed issue. As he mentioned, PC-1 became immensely popular among the academic researchers, and many commercial entities adopted parametron to create very successful commercial computers. In Goto's mind as its leader to build PC-1, the computer may not have had that much impact, but others and commercial enterprises in Japan of that era had a very different opinion. *2: Obviously, Goto referred to the budget of similar computer project, NOT the entire MIT budget.
Many private companies adopted parametron to build computers and calculators soon. Some models sold very well in the era. (See the list in Appendix I).
Also, after parametron became famous, a non-profit organization OUTSIDE
the University of Tokyo was established to handle the funding and
intellectual property issues, which lead to the next item.
Intellectual Property and Collaboration
Navigating intellectual property rights and fostering collaboration with international researchers were political challenges. The exchange of knowledge and technology between countries was often hindered by political considerations and restrictions. Establishing frameworks for collaboration and ensuring the protection of intellectual property were critical for advancing Parametron research.
Because the significance of parametron was so clear to the early adopters, they began helping Goto patent the inventions. To proceed with international patenting, an outside NPO called Parametron Research Laboratory (tentative English translation) was formed in Mar 8, 1957 (The birth of a computer, 1971 [13]) and the intellectual property matters were handled by this entity after that, freeing Goto, Takahasi and others at the University so that they could focus on technical inventions at hand.
Two US patents for Goto's parametron were granted.: US Patent 2,948,818 [P1] and [P2] US Patent 2.948,819. They were initially turned down with a comment, "it does not operate". ([13] p.82]). A US company, NCR licensed the patents eventually but did not produce anything after about a year and its interest seemed to have disappeared. It was too late, in a sense, since the transistors became more robust, and parametron's advantage was disappearing very fast.
Goto's mentor, Professor Takahasi wrote the following in 1971 [13] (in submitter's English summary). This is a food for thought for today's inventors/researchers.
"Fearing the publication of the technology might invalidate the patent applications, we took the hush hush approach, not publishing the new technical results any longer. But with hindsight, it may have been better to adopt a more open approach to share technology even its current problems, with other parties early. Then the technology might have been used wider (Proposer's comment: outside Japan, too, implicitly) and problems may have gotten solved with more inputs from many parties. I think this approach might have worked better for parametron."
Geographic Obstacles
Research Infrastructure
Japan's research infrastructure was still recovering from the devastation of World War II. Establishing well-equipped laboratories and securing access to advanced research facilities were significant geographic challenges. Researchers had to overcome the limitations of the existing infrastructure and build new capabilities from the ground up.
Although Takahasi lab was hardly a rich laboratory back when parametron was invented, it enjoyed a better than average status because the University of Tokyo was the largest nation-run university of that time.
Access to Global Knowledge
Geographic isolation posed challenges in accessing the latest research and technological advancements from other parts of the world. Japanese researchers had to find ways to stay informed about global developments in electronic computing and incorporate this knowledge into their work. Building networks and establishing communication channels with international researchers were essential for overcoming this obstacle.
The following anecdote may seem outlandish to readers in the 21st century. However, Professor Takahasi (and people in other field such as physics, etc. of that time for that matter) mentioned that he learned of transistor and other technical discoveries in the world, via magazines made available at a library established by an occupying forces stationed in post-war Japan. University libraries were not functional at all back then.
There was a library in Hibiya, Tokyo, established by the general headquarters of the occupying force in post-war Japan and that was the place to go to read the latest American magazines including technology/science ones. CIE Information Center Library was it. So being in Tokyo, the capital of Tokyo was important. (There were similar CIE libraries in other parts of Japan, but Tokyo's Hibiya one seemed to have been largest. https://ja.wikipedia.org/wiki/CIE%E5%9B%B3%E6%9B%B8%E9%A4%A8) Takahasi, Goto and others seemed to have learned of the EDSAC computer which they seemed to have studied extensively before the construction of PC-1 from learning about it through reading at this library in Hibiya. It no longer exists.
Goto himself did not leave much about his study style in writing and the submitter could not learn much about WHERE he obtained knowledge. His research style, though, was to think hard about a topic himself very much and arrive at a solution or two, or even more before seeing other people's previous work.
Market Acceptance
Introducing a novel technology like the parametron to the global market requires overcoming geographic barriers. Domestic market in Japan accepted parametron very quickly and produced computers based on it. Some of them (NEAC-1201 and NEAC-1210) sold more than 700-800 units, which was a big number for computer sales at the time. (See Appendix I)
Convincing international markets of the parametron's advantages and securing adoption outside Japan involved addressing cultural and logistical challenges. Establishing distribution channels and support networks in different regions were crucial for the parametron's success.
That NCR licensed the Goto's parametron patent was a testament to the advantage of the parametron device at the time. Whether there was a strong support network to help NCR proceed is now a question of historical interest. There was no internet, no e-mail, no international fax.
There is anecdotal evidence that European companies also monitored parametron development. But it is only in one person's memoir of parametron. ("TOYOTA and parametron electronic computer FACOM 202", Yoshihiro Ishibashi, available online at: https://www.toyotariken.jp/_/media/page/about/research-report/pdf/Toyota-Report_No.77_62.pdf) Submitter's translation of the relevant paragraph follows.:
--- Yoshihiro Ishibashi's recollection
The author's specialty is “ferroelectric properties”, and when
talking with foreign researchers who have the same specialty, the
topic sometimes turns to graduate school days. When the parametron
is mentioned in such a situation, of course it is passed over with
“what's that?”, but there was one occasion when I got a
reasonable response. It was from a British researcher of the same
age, and therefore someone who knew about the situation with
computers in the 1960s, who said, “I know about the
parametron. Thomson (France) studied it, but it didn't work, did
it? Did you really make a computer using parametron in Japan?” It
seems that parametrons were not completely ignored in Europe. It
didn't mean much, but it made me feel happy somehow.
Note: Yoshihiro Ishibashi was a graduate student in 1958 and
studied under the supervision of Eiichi Goto. He was still a
graduate student when he gave a talk at the programming seminar
hosted by Japan Physics Society using PC-1 in 1959.
These technical, political, and geographic obstacles were significant, but the dedication and ingenuity of Dr. Eiichi Goto and his team led to the successful development and implementation of the parametron. Their achievements laid the groundwork for future advancements in electronic computing in Japan and demonstrated the resilience and innovation of the scientific community in overcoming complex challenges.
What features set this work apart from similar achievements?
Features that set this work apart from similar achievements
Comparison with Other Methods
In the following, we compare the parametron with vacuum tube, relay, and transistor types of the 1950s:
Please note that advantage and disadvantage of parametron such as speed,
power consumption, etc. are discussed in the relationship with other
devices in the following.
For example, the power consumption of PC-1 *WAS* huge in
comparison to today's power efficient computers, but was definitely
smaller RELATIVE to the vacuum tube computers.
(PC-1 computer's power consumption was 3KVA as shown in table-1.)
Pros
(a) The price is significantly lower compared to vacuum tubes (and more so than transistors).
(b) Compared to relays, it can operate at higher speeds.
(c) It is more stable than vacuum tubes with relatively short life cycle and early transistors.
(d) Ferrite cores possess physical strength due to being made of ceramics.
(e) Errors due to radiation are less likely to occur.
Cons
(a) It consumes more power than transistors (less power than vacuum tubes).
(b) While transistor calculators of the same era achieved an operating frequency of 1 megahertz, the parametron operated at about 10-30 [kHz], making it slow.
This was due to the fact that the parametron's internal frequency is half the excitation frequency, and that an observation of a few full cycles of parametron output is necessary to ascertain the phase shift to determine the logical output, i.e., 0/1. Thus the frequency of parametron's logic operation at least 16-20 times as slow as the excitation frequency.
To try to achieve higher speed operation of parametron, it was necessary to feed much very fast external excitation frequency. So this was the inherent limit of parametron speed. And it also compound the power consumption issue, (a) above, since the excitation frequency circuit is basically the power source, and it had to operate at a very high frequnecy.
When Goto later became friends with John McCarthy of Lisp fame at MIT, he was asked, "Parametron is an interesting idea, but why did you make such a slow device?". (The true answer to this question was because the research budget of Goto's at the University of Tokyo was 1/1000 of similar MIT project according to Goto, but he did not say this to McCarthy then because of his national pride.) The speed difference between parametrons and junction transistors is notable; parametrons operated at a much lower frequency, leading to slower performance.
A detailed comparison of speed of various parametron computers and others in the same era is given in Appendix V.
Because ferrite core had hysteresys, when excited at high freqency, it loses the energy as dissipation heat, which leads to the next disadvantage.
(c) Due to the heat generation (caused by loss due to the hysteretic characteristics of the magnetic material), increasing the operating frequency causes the ferrite core to overheat, altering its magnetic characteristics (burning) and hindering operation.
(d) It does not function properly when miniaturized, making it challenging to integrate using microfabrication technology.
(e) Boolean logic used for other devices was not useful. Parametron used majority logic instead of simple Boolean logic of AND/OR/NOT. So the logic design was initially difficult until Goto's team that created PC-1 came up with the better classification of multi-input functions to give a bird view of the logic design that uses majority logic, so to speak. (See the full discussion in "Design Complexity", in the Obstacle section.)
(f) Fan out is not large. (This disadvantage was thanks to the comment from one of the reviewers).
You cannot drive many parametron devices from the output of a single parametron. It was observed that the parametron's oscillation is adversely affected if too many fanout signals are extracted.
So, for the design of PC-1, the fanout was limited to 12. We can always duplicate a logic stage to duplicate the desired output so that this fanout limit is not overcome and the speed is not lost due to the additional logic stage. Yet, this step may introduce an overflow of the fanout limit in the previous logic circuit stage. We have to repeat the process until the fanout condition is met at all the logical stages. Will this step eventually stop or will the fanout limit make the design using parametron infeasible?
Luckily, Goto proved that these steps to eliminate fanout overflow will always stop as long as fanout F is larger than fanin (I = 5 in the case of parametron used for PC-1). (E. Goto: "A Note on Logical Gain", IEEE Transaction on Electronic Computers" EC-13, October 1964) This fanout and fanin relation holds for any type of logic circuit.
So, although this fannout limit of parametron may have expanded the
area of circuit boards to accommodate more parametrons, this was NOT
an inherent design limitation.
Logic Elements Similar to Parametrons
Capacitance Variable Type Parametron
Goto's parametron uses variable inductance (L). Around the same time as Goto's patent application (filed in April 1954), von Neumann proposed the idea of using parametric oscillations that change capacitance (C) or inductance. But his patent described the very meta-level of the IDEA of a parametron using microwave as the oscillation source and whether he tried to implement it and would have succeeded remains very mute. But Von Neuman did notice both the amplifying feature of input signal and memory feature of the parametron-like device as Goto did. (Von Neuman patent: U.S. Patent 2,815,488 "Non-linear capacitance or inductance switching, amplifying, and memory organs " applied in 1954 and published in 1957. Accessible online at the following URL: https://patents.google.com/patent/US2815488A/en)
There was a demonstration of C-type parametron by Hashizume et al in 2018. (https://siogadget.wordpress.com/2008/03/27/%E3%83%91%E3%83%A9%E3%83%A1%E3%83%88%E3%83%AD%E3%83%B3%E8%A8%88%E7%AE%97%E6%A9%9Fpc-1%E8%AA%95%E7%94%9F50%E5%91%A8%E5%B9%B4%E8%A8%98%E5%BF%B5%E3%81%AE%E4%BC%9A%E5%90%88%E3%81%A7%E3%81%AE%E5%B1%95/ in Japanese ).
Thin-Film Magnetic Material Parametron
Following the same principle, parametrons using thin-film magnetic materials were also studied, but they were not commercialized on a large scale.
Magnetic Flux Quantum Parametron
Magnetic flux quantum parametrons have also been studied. Proposed in 1984 by Goto (E. Goto, "Josephson pair elements", Proc. 1st RIKEN Symp. Josephson Electronics, pp. 48-51, 1984., E. Goto and K. F. Loe, DC Flux Parametron, Singapore: World Scientific, 1986.). as a switching element capable of high-speed operation up to 16 GHz using the Josephson effect, these elements have principles similar to those of parametrons. Goto mentioned in an interview, "The fact that the principle is similar to parametron means that the same person can think about it." In addition to high-speed performance, these elements are characterized by power saving compared to other superconducting devices (such as Josephson elements), but large-scale integration has not been achieved. While they use quantum mechanics, they are not considered quantum computation in the conventional sense. [ref: https://en.wikipedia.org/wiki/Quantum_flux_parametron]
Goto invented the QFP in 1984 as a low-power high-speed switch element. but the industry's mainstream investigated different superconducting logic circuit using different mechanisms since then.
Additionally, a reversible computational element using adiabatic quantum parametron (AQFP) approaching the limit based on Landauer's principle has been proposed.
However, lately, the energy-saving feature of QFP has revived its popularity, and AQFP is now a hot topic. The history of QFP and recent trends are explained in detail in [REF: Adiabatic Quantum-Flux-Parametron: A Tutorial Review, https://www.jstage.jst.go.jp/article/transele/E105.C/6/E105.C_2021SEP0003/_article ]
Appendix III discusses briefly the parametron-like devices including QFP that were born after the original parametron was invented by Goto.
Why was the achievement successful and impactful?
The invention of the parametron in 1954 was successful and impactful
due to several key factors.
Firstly, the parametron, developed by Goto, was a revolutionary
advancement in electronic computing technology. Unlike traditional
vacuum tube-based computers, the parametron utilized parametric
oscillation, which significantly reduced power consumption and
reliability was improved by leaps and bound. This technological advantage
addressed the major limitations of early computers, making them more
practical for widespread use.
Additionally, the parametron's design was versatile and adaptable,
allowing for various applications in different fields. It found use in
scientific research, industrial automation, and other field. The
flexibility and efficiency of the parametron paved the way for further
advancements in computing technology and set the stage for future
innovations.
Lastly, the parametron's success was not just limited to its
technical merits. It also had a lasting impact on the development of
computer science education in Japan. Many universities and research
institutions adopted the computers that used parametron for teaching
and research purposes, fostering a new generation of computer
scientists and engineers. (Some universities display the original
parametron computers thus used as memento of the birth of computer
education at their institution. See Appendix I.)
This educational impact contributed to the
rapid growth of Japan's technological workforce and the country's
continued leadership in the field.
The parametron's impact extended beyond just technological
innovation. It played a pivotal role in establishing Japan as a player
in the field of computing during the post-war period. At a time when
Japan was rebuilding its industrial and technological capabilities,
the success of the parametron demonstrated the country's ability to
innovate and compete on the global stage. This accomplishment
instilled a sense of national pride and confidence in Japanese
scientists and engineers. This left an impact on the future computer industry.
In summary, the success and impact of the parametron invented in 1954 can be
attributed to its technological innovation, national significance,
versatile applications, and its role in advancing computer science
education in Japan.
Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.
Bibliography
References
Note: In many articles from the 1950s, Hz (Herz) for the unit of frequency is NOT used. Instead C or c (cycle) is used. This may require caution when one reads the old document.
[1] Hidetosi Takahasi, Eiichi Goto, Hiroshi Yamada: "On Mechanical and Electronic Calculation Methods", Technical Committee on Electronic Computers of the Institute of Electrical Communications, 1954. (In Japanese). <pr> Original Japanese title: 機械電子式計算方式について, 高橋秀俊、後藤英 一、山田博, 1954年1月29日
[Remarks] This Reference [1] is a pair with the next Reference [2]. Reference [1] is the main text, and Reference [2] is the explanatory diagram.
The explanation of this reference [1] and the following reference [2] are given in the Appendix IV.
Media:Takahashi_19540129_1.pdf
[2] Hidetosi Takahasi, Eiichi Goto, and Hiroshi Yamada: "On Mechanical and Electronic Calculation Methods (Explanatory Diagram)", The Technical Committee on Electronic Computer Research of the Society of Electrical Communicators, 1954. (In Japanese). <pr> Original Japanese title:機械電子式計算機 説明図
[Remarks] This Reference [2] is a pair with the above Reference [1]. Reference [1] is the main text, and Reference [2] is the explanatory diagram.
Media:Takahashi_19540129_2.pdf
[3] Hidetosi Takahasi, Eiichi Goto: "Counting Circuits of
Parametrons", Technical Committee on Electronic Computers of the
Institute of Telecommunications, September 1955. (In Japanese).
Original Japanese title: パラメトロンの計数回路, 高橋秀俊, 後藤英一,
電子計算機研究専門委員会資料, 1955年9月26日
The following is an English summary of the content. Abstract: Parametrons are typically designed as two-terminal elements and are primarily constructed using capacitors and transformers. These elements transition between different "energy states", with the internal state changing in response to an external driving signal (input signal). Specifically, the amplitude and phase of the input signal allow the parametron to hold two stable states (0 and 1) and perform logical operations by transitioning between them.
Counting Circuits Using Parametrons: When parametrons were used to create counting circuits, the design focused on the following key features:
(a) Counting circuits: Parametron-based counting circuits combine multiple parametron elements to implement counting.
(b) Digital logic circuits: Parametrons can serve as basic logic gates (e.g., AND, OR, NOT), which can be combined to create more complex computational circuits, such as adders and multipliers.
(c) Advantages of parametrons: Compared to conventional circuits that use vacuum tubes and transistors, parametron circuits offer enhanced stability.
[4] Hidetosi Takahasi, Eiichi Goto, Yukio Murakami, Hiroshi Yamada: "Parametron Computer PD-1516", Technical Committee on Electronic Computers of the Institute of Electrical Communications, April 1957. (In Japanese).
Original Japanese title: パラメトロン計算機, 高橋秀俊・後藤英一・村上
幸雄・山田博
電子計算機研究専門委員会資料, 1957年4月
[Remarks] This was more like a calculator due to the initial limitation of small number of memory words. It is not a fully programmable stored-program computer of today.
Abstract: The PD-1516 is a parametron computer that was jointly developed by the University of Tokyo and Japan Electronics Instruments in October 1956. It had six words of internal storage initially. A parametron is a type of logic element that uses a ferrite core and is known for its low cost and stable operation. The PD-1516 was a calculator equipped with 16 registers, each capable of holding 15 decimal digits. The programming of this calculator was carried out using a symbolic programming language form. It contributed to the early days of computing industry in Japan.
[5] Hidetosi Takahasi, Eiichi Goto, Eiiti Wada, Takashi Soma,
Yoshihiro Ishibashi, Keisuke Nakagawa: "On the PC-1 Parametron
Computer, (1.Structure of PC-1 and 2.Program of PC-1)", Technical
Committee on Electronic Computers of the Institute of Electrical
Communications, September 25, 1958. (In Japanese).
Original Japanese title: パラメトロン計算機, 高橋秀俊・後藤英一・村上
幸雄・山田博、電子計算機研究専門委員会資料, 1957年4月
Abstract: (Translated summarized from the original Japanese by the submitter.)
The PC-1 (Parametron Computer No. 1) is a universal scientific computer that uses parametron technology, developed by the Takahashi Laboratory at the Faculty of Science, University of Tokyo. Production began in 1957 and was completed in 1958. The computer contained 4,200 parametrons, while its input/output and storage devices were sourced from various companies. Notably, the reliability of the AC magnetic core storage device is exceptional, featuring an error-correction circuit that operates normally even if a single vacuum tube fails.
The PC-1 operates internally using the binary system and supports fixed-point arithmetic. It was the fastest computer in Japan at the time (Proposer's comment: when this article published in September 1958 was written), operating 9 to 12 hours a day, with 5 hours dedicated to numerical calculations for various scientific departments, and the remaining time used for program development within the laboratory.
One of the key features of the PC-1 is its use of an AC magnetic core storage unit, ensuring stable operation. The calculation speed is enhanced by carry-lookahead circuit in the arithmetic circuit. Notably, innovations in numerical representation methods and parallel computing control have improved calculation speed by up to 2 to 3 times.
Plans for the PC-2 are already underway. Building on the experience gained with the PC-1, the PC-2 will feature enhanced memory capacity, high-speed I/O equipment, and floating-point computing capabilities. The design of the PC-1 includes a streamlined configuration of arithmetic circuits for addition, multiplication, and division, with particular attention to the addition circuit, high-speed multiplication processing, and division correction processing. The structure of the PC-1 was specifically devised to optimize efficiency and performance, and a similar approach will be applied to the design of the PC-2.
Media:PC-1_19580925.pdf
The proposer believes that the above copy is a scanned and OCR'ed copy
of the original.
[6] Eiichi Goto: "Parametron Computer PC-1", Information Processing,
Vol. 16, No.1, pp. 39-43, 1975. (In Japanese).
Original Japanese title: パラメトロン計算機 PC-1 - 日本における計算機
の歴史 -, 後藤英一、情報処理, vol. 16 No. 1,
[Remarks]
Reference [6] covers the same technical content as Reference [5]
concerning the PC-1. However, this reference [6] emphasizes the PC-1's
role as a milestone in the history of computing in Japan. This
distinction arises because reference [5], written by Takahashi in 1958
during PC-1's development, contrasts with the reference [6], written
by Goto more than 15 years later, after the PC-1 had been established
as a device of historical significance.
For example,
reference [6] provides a detailed account of the development history
of the PC-1, the various challenges encountered during its creation,
and its operational methods.
[7] Hidetosi Takahasi: "Some Important Computers of Japanese Design", IEEE Annals of the History of Computing, Vol.2, No.4, pp. 330-337. Oct.-Dec. 1980, doi: 10.1109/MAHC.1980.10043.
[Remarks] Note the phrase "we were on the verge of starvation in the ruin of our defeated country", and "We were starved for knowledge as well as for food". Such was the atmosphere of post-war Japan when parametron was invented.
Abstract: Rapid growth of the computer industry is one of the most striking events in the "miraculous" industrial explosion of postwar Japan. At the time the ENIAC was completed at the Moore School of Electrical Engineering, we were on the verge of starvation in the ruin of our defeated country. When we learned of the astonishing power of the "giant brain," it seemed indeed to be something belonging to another world. We were starved for knowledge as well as for food, and some of us who were optimistic enough were inspired by this fascinating new technology. We decided to make our own computers, and the study of "mechanical brains" got under way in Japan.
[8] Chigusa Kito; "PC-1 Parametron Computer, 50th anniversary", Events and Sightings, IEEE Annals of the History of Computing, Vol. 30, No.3, pp. 74-77, July-September 2008.
https://muse.jhu.edu/article/247703
Media:Event and Sightings_2008.pdf
[9] E. Goto: "The Parametron, a Digital Computing Element Which Utilizes Parametric Oscillation", Proceedings of the IRE, Volume: 47, Issue: 8, pp. 1304 - 1316, August 1959, DOI: 10.1109/JRPROC.1959.287195
[Remarks] This paper won the prestigious IRE Memorial Prize Award in Memory of Browder J. Thompson in 1961.
Abstract: The following is a brief description of the basic principles and applications of the parametron, which is a digital computer element invented by the author in 1954. A parametron element is essentially a resonant circuit with a nonlinear reactive element which oscillates at one-half the driving frequency. The oscillation is used to represent a binary digit by the choice between two stationary phases π radians apart. The basic principle of logical circuits using the parametron is explained, and research on and applications of parametrons in Japan are described.
[10] E. Goto; K. Murata; K. Nakazawa; K. Nakagawa; T. Moto-Oka; Y. Matsuoka; "Esaki Diode High-Speed Logical Circuits",
IRE Transactions on Electronic Computers, Volume: EC-9, Issue: 1, pp. 25 - 29, March 1960
DOI: 10.1109/TEC.1960.5221600
Abstract: Logical circuits using Esaki diodes, and which are based on a principle similar to parametron (subharmonic oscillator element) circuits, are described. Two diodes are used in series to form a basic element called a twin, and a binary digit is represented by the polarity of the potential induced at the middle point of the twin, which is controlled by the majority of input signals applied to the middle point. Unilateral transmission of information in circuits consisting of cascaded twins is achieved by dividing the twins into three groups and by energizing each group one after another in a cyclic manner. Experimental results with the clock frequency as high as 30 mc are reported. Also, a delay-line dynamic memory and a nondestructive memory in matrix form are discussed.
Submitter's note: "30 mc" means "30 MHz" in today's parlance, that is, "c" stands for "cycle" Media: Goto_EsakiDiode.pdf
[11] Eiiti Wada: "The Initial Input Routine of the Parametron Computer PC-1", pp. 435-452 in Raúl Rojas, Ulf Hashagen ed: "The First Computers: History and Architectures", MIT Press, 2002.
Abstract: Forty years ago, the PC-1, parametron computer 1, was born at Professor Hidetosi Takahasi's Laboratory. The logical elements of the PC-1 were parametrons, which supported majority logic. The memory system operated in a two frequency read/write scheme. The word selection mechanism applied error correcting code to decrease the number of elements. Most of the hardware technologies were created by Eiichi Goto.
We studied the EDSAC computer precisely, however we developed our own architecture and programming system based upon our own philosophy. The machine instruction set was chosen to ease programming. The normal teletype on the market was employed, leaving the burden of code conversion tasks to software, which seemed to us to have had almost infinite abilities.
However, the real memory capacity was indeed very small, which forced us to invent a clever way to implement things. In this paper, after introducing the functions of the initial input routine R0, examples of (i) code conversion table parasitic on the program body and (ii) the magic number method to control the number of multiplications, both used in the initial input routine, are described. The PC-1 is one of the first computers which implemented interruption. That is, the peripheral devices would interrupt the running program by saving the address of the next instruction to be executed and jumping to a fixed location in the memory. As a simple experiment of multiple programming, cooperation of the binary to decimal conversion program and the printer control program by means of the circular buffer was performed.
At the end of this paper, the program lists of the selected routines are appended.
[12] M. V. Wilkes, D. J. Wheeler and S. Gill: The Preparation of Programs for an Electronic Digital Computer. Addison-Wesley Press, Inc. 1951.
[13] Hidetosi Takahasi, "電子計算機の誕生" (Birth of an Electronic Computer in Japanese), Chuo-Koron Sha, 1971.
[14] Committee for the 50th Anniversary of PC-1, "パラメトロン計算機 PC-1 1958-2008" (Parametron Computer PC-1 1958-2008 in Japanese), https://www.iijlab.net/~ew/pc1/pc150th.pdf),
Patents
[P1] EIICHI GOTO: "RESONATOR CIRCUITS", US Patent 2,948,818, Filing: May 16, 1955. Patented: Aug. 9, 1960.
[P2] EIICHI GOTO: "DEVICE COMPRISING PARAMETRICALLY EXCITED RESONATORS", US Patent 2.948,819, Filing: Feb. 27, 1956. Patented: Aug. 9, 1960.
Awards
[A1] IRE Memorial Prize Award in Memory of Browder J. Thompson, in 1961.
Citation: For his paper entitled “The Parametron, a Digital Computing Element which Utilizes Parametric Oscillation,” which appeared in August 1959 issue of Proceedings of the IRE. (reference [9] of this proposal document.)
The IEEE Browder J. Thompson Memorial Prize Paper Award was established in 1945 and is presented for the most outstanding paper in any IEEE publication issued between 1 January and 31 December of the preceding year by an author or joint authors under thirty years of age at the time the original manuscript was submitted. The award has been replaced by Leon K. Kirchmayer Prize Paper Award since 1997. (https://ethw.org/IEEE_Browder_J._Thompson_Memorial_Prize_Paper_Award)
[A2] Winner of the Asahi Prize (1959)
This was given for his contribution to PC-1 computer.
The Asahi Prize (朝日賞, Asahi Shō), established in 1929, is an
award presented by the Japanese newspaper Asahi Shimbun and Asahi
Shimbun Foundation to honor individuals and groups that have made
outstanding accomplishments in the fields of arts and academics
and have greatly contributed to the development and progress of
Japanese culture and society at large. (from Wikipedia,
https://en.wikipedia.org/wiki/Asahi_Prize)
Appendix I: Detailed list of commercial Parametron computers
Many commercial parties and research institutes set out to develop computers based on parametron in Japan after Goto's invention was announced. Here is the list of such computers and the current status of exhibition display, if available.
Japan Electronics Instruments
PD-1516 (1956): This was more like a calculator because it had
initially only 6 words of memory. Development division was later moved to Fujitsu.
https://museum.ipsj.or.jp/en/computer/dawn/0051.html
The University of Tokyo (Takahasi Laboratory)
PC-1/4 (1957): A preliminary experimental model of the PC-1, about the size of a notebook. It can perform arithmetic on binary numbers each with 9 bits. The input device has only 7 toggle switches. PC-1 was going to use a binary number of 36-bit. This machine used 9-bit number, thus 1/4.
PC-1 (1958): A full 36-bit stored-program machine with a 2 m wide and 1.5 m high chassis. (Japan Electronics Instruments, Fujitsu [6]). A female employee responsible for relay wiring produced 4,300 parametrons. The excitation frequency is 2 MHz, and the operating frequency is 15 kilohertz. The storage device has 256 bytes. The instruction set includes simple addition, subtraction, multiplication, and division. It features a "high-speed digit raising circuit" for fast addition, multiplication, and division, based on Goto's own idea, and "proactive control" for performing multiple instructions simultaneously. The input and output use 6-hole perforated tape. The first program is an "erased blank" (literal translation: blank erasure) that skips only the parts where no data is written ("00" in hexadecimal). It is reported that many people from outside came to use it. It has been dismantled and no longer exists.
PC-2 (1960): Funded by the Ministry of Education, it was jointly developed with Fujitsu. It is an enhanced version of the PC-1 for scientific calculations, using 13,000 parametrons. The excitation frequency is 6 MHz, and the operating frequency is 60 KHz. The word length is 48 bits. It includes functions such as floating-point arithmetic, data search, and multiplication unit that uses multiplication of 4 bits by 4bits entity. It was the fastest parametron computer and outperformed the transistor-based ETL Mark IV A (although junction transistors were still at a speed disadvantage at the time) [7]. It took 9 seconds for a 1000-digit calculation of the natural logarithm. It was commercialized as FACOM 202. FACOM 202 had four times as many memory words as PC-2, and performed two to three times as fast as PC-2 when fixed point addition and multiplication were performed.
https://museum.ipsj.or.jp/en/computer/dawn/0035.html
There is a short description of how FACOM 202 was used at the Institute of Solid State Physics in the newsletter of the Institue, p. 17, No. 5, Vol 4, December 1964, in Japanese, available online at https://www.issp.u-tokyo.ac.jp/maincontents/docs/tayori/tayori04-5.pdf. Notable feature of FACOM 202 was the use of Algol language compiler which made it easier for researchers to use it than the machine language assembler.
Nippon Telegraph and Telephone Corporation (Telecommunications Research Institute)
MUSASINO-1 (1957): Initially had only 32 words using magnetic core memory (later expanded to 256 words). The instruction set was based on ILLIAC 1.
Despite the meager 32 words initially, MUSASINO-1 did show that
parametron can be used to build a complex circuit such as CPU and it
also acted as a test bed for parametron's durability. Later, in 1960,
NTT produced a commercial version called MUSASINO-1B that required
much less maintenance, which was later sold as FACOM 201 by today's
FUJITSU. NTT produced a billing machine using parametron later, too.
https://museum.ipsj.or.jp/en/computer/dawn/0013.html
MUSASINO-1B (1960): Jointly developed with Fujitsu. Commercialized as the FACOM 201.
CAMA (1963): For call billing only, not programmable.
https://museum.ipsj.or.jp/en/computer/dawn/0032.html
Hitachi
HIPAC MK-1 (December 1957): The company's first computer.
https://museum.ipsj.or.jp/en/computer/dawn/0015.html
A model is displayed at the Central Research Laboratory of Hitachi
Corporation as of Feb 2025.
HIPAC 101 (1960): Commercialized.
https://museum.ipsj.or.jp/en/computer/dawn/0019.html
HIPAC 103 (August 1961): Commercialized. For scientific and technical calculations.
https://museum.ipsj.or.jp/en/computer/dawn/0041.html
NEC
NEAC-1101 (1958): The company's first computer.
https://museum.ipsj.or.jp/en/computer/dawn/0017.html
NEAC-1102 (1958): Jointly developed with Tohoku University and
delivered to the Electrocommunications Research Institute, Tohoku
University. Also known as SENAC.
It was delivered to Tohoku University in March 1958, but was not made
available for full scale operation until November 1958.
https://museum.ipsj.or.jp/en/computer/dawn/0020.html
NEAC-1103 (1960): Delivered to the National Defense Agency Technical Research Laboratory.
NEAC-1201 (1961): Commercialized as an office computer. Its successors
were NEAC-1202 and NEAC-1210.
NEAC-1201 was quite a success as a small computer at that
time. It may be better called tabulator because it had only 120 words
although it WAS a stored program computer.
More than 800 units were sold which was beyond the
initial expectation of 200-300 units sold in total according to "History
of First and Second Generation Japanese Computers and the Preservation
of (Early) Examples" by Akihiko Yamada, in "技術の系統化調査報告 第１
集" （"Systematic Study of Technology Report", Volume One in Japanese)
by National Museum, March 2001.
The successor 1210 sold well, too.
https://museum.ipsj.or.jp/computer/dawn/0040.html (in Japanese)
NEAC-1210 (1964): It sold well. 700+ units sold by August 1966.
https://museum.ipsj.or.jp/computer/dawn/0060.html (in Japanese)
Oki Electric
OPC-1 (1959):
https://museum.ipsj.or.jp/en/computer/dawn/0023.html
INS-1 (circa 1962): Installed at Japan Nuclear Research Institute
(which was established in July 1955).
The sketchy description of manufacturing and installation of this
computer is only found in the following Japanese page.
https://www.hpcwire.jp/archives/40591 (in Japanese)
Fujitsu
FACOM 200 (September 1958): A prototype that of computers that followed.
https://museum.ipsj.or.jp/en/computer/dawn/0062.html
FACOM 212 (Shipped in April 1959): Commercialized as an office computer. One word was 12 decimal digits. 32 words of magnetic core memory. One word could hold 4 instructions. So, in total, 128 instructions could be used.
FACOM 201 (1960): Commercialization of MUSASINO-1B.
A machine is on permanent display in 2018 at Tokyo University of Science.
A photo is in the following URL.
https://www.jaima.or.jp/resource/jp/heritage/pdf/2016_No66_67.pdf
Quote of the paragraph in the URL.
The parametron, invented in Japan as an original, unique logic element, was used in a number of Japanese computers as a cheap and robust logic unit in the transition period from the vacuum-tube era to the transistor era. It is of tremendous value as technological heritage. Approximately 6,000 parametron units are used in this computer.
This computer was utilized in Tokyo University of Science for the purposes not only of scientific computations but also of technology developments such as “effects of the shape of a small rocket on the propulsion by solid fuel combustion” and “theoretical computations of the strength of car-body structures”. Furthermore, it was employed for the education of computer technology and contributed to training engineers.
Display of a large computer: FACOM 201
https://www.tus.ac.jp/info/setubi/naruhodo/main/calculators.html
(in Japanese)
Tokyo University of Science even organized an event on "Parametron
computers and relay computers." in 2018.
https://www.tus.ac.jp/info/setubi/museum/event_data/2018parametron/2018parametron.html
(In Japanese)
[Remarks] The above event reflected the impact parametron had on the Japanese
computer industry and education in the late 1950 and the 1960s.
FACOM 202 (1960): Commercialization of the PC-2. For scientific and technical calculations. At the time of completion, it became the fastest computer in Japan.
Mitsubishi Electric
MELCOM 3409 (1960): Mitsubishi immediately switched to using transistor after this machine, and not much material is available online.
Koden Electronics Co., Ltd.
KODIC-401 (1960): Experimental prototype.
KODIC-402 (1961): General-purpose computer. Commercialized with an operating
frequency of 2 MHz, decimal 16-digit fixed-point stored programming,
and a magnetic drum storage device with 4000 words. A total of three
systems were delivered for in-house use, including one to the Faculty
of Engineering at Japan University and another to the Department of Industrial
Engineering, Faculty of Engineering, Osaka Electro-Communication
University (OTSUDAC-1, delivered in March 1963, currently on display
and preserved).
OTSUDAC-1 was on display at the university in 2014. (https://www.hpcwire.jp/archives/41516)
The following is a press release (in Japanese) regarding the chair of Koden Electronics, Mr. Itoh,
visiting the display on July 14, 2014.
https://www.osakac.ac.jp/news/2014/327
[Remarks] The following excerpt showed the impact of parametron-based computer on education at universities in Japan circa 1960.
An excerpt from the release (translated by the proposer):
... This electronic computer was produced by Koden Co., Ltd. around 1963, and is said to be very valuable as an early computer using a parametron element at a time when computers were not yet widespread. The University was the first university to introduce this computer for education and research, and has preserved it on the second floor of Building M at the Neyagawa Campus since 1976 to commemorate the achievements of that time. ...
Appendix II: subroutines and the type of calculations done on PC-1
These are taken from references [6] and [14].
Takahasi/Goto Lab:
Interrupt handling multitasking
Fast Fourier Transform (very similar to the FFT known later)
Elliptic function table based on summation rule
Exact calculation of integer arithmetic of arbitrary length using modular arithmetic
Numerical simulation of Goto pair
Created by others:
Eigenvalue solver for symmetric and asymmetric matrices
(Solving 10x10 matrix problem in 512 words PC-1!)
Partial differential equation solver
Nuclear (Magnetic) Moments of atoms
Calculation in two coulomb center potential field
Dispersion Relations in Nucleon scattering
Crystal structure analysis
Electron beam diffraction analysis of gas
Molecular vibration analysis for spectroscopy
Among the researchers who did the molecular vibration analysis
was Mitsuo Tasumi (1937 – 2021).
He received the prestigious Optics Society of America's Ellis
R. Lippincott Award in 1999“for outstanding contributions to
vibrational spectroscopy in studying the structures and
dynamics of synthetic polymers, proteins, photosynthetic
systems, and a number of related small molecules.”
https://www.optica.org/History/Biographies/bios/Mitsuo_Tasumi
His thesis calculations were done on PC-1 and PC-2.
He left his memoir regarding the 50th anniversary of PC-1 in
2008, and stated that PC-1 has determined his career.
http://sapiarc.web.fc2.com/Essay/2008/2008-03.pdf (in Japanese)
There were many more, but Goto stated in [6] (written in 1975) that many researchers who did the calculation on PC-1 were scattered around the world and he could not obtain much information already in 1975. He specifically mentioned detailed information on ordinary differential equation solver, and solver for partial differential equation for magnet design were missing from [6].
Appendix III Parametrons in Disguise
Original parametron invented in 1954 used ferrite core. The idea of parametron, i.e., parametric oscillation, recurred later from time to time in different forms in designing digital circuits and certain applications.
Goto Pair
When Tunnel diode (https://en.wikipedia.org/wiki/Tunnel_diodewas) was invented, Goto created a new device consisting of two tunnel diodes called Goto pair. (See the reference [10], E. Goto; K. Murata; K. Nakazawa; K. Nakagawa; T. Moto-Oka; Y. Matsuoka; "Esaki Diode High-Speed Logical Circuits")
This is actually a parametric device of a sort. The logic device achieved 30 MHz operation which was quite an impressive achievement back in 1960.
Quantum flux parametron
Much later, Goto realized a parametric oscillation can be observed in a super-cooled Josephson-junction device, and devised a logic device called quantum flux parametron in 1986, and carried out research on it. (https://en.wikipedia.org/wiki/Quantum_flux_parametron)
This was explained in the "Features that set this apart from other similar achievements" section, and the version of QFP called Adiabatic Quantum Flux Parametron (AQFP), with its energy-saving feature, seems to attract attention again in energy-aware computing industry of today. [REF: Adiabatic Quantum-Flux-Parametron: A Tutorial Review, https://www.jstage.jst.go.jp/article/transele/E105.C/6/E105.C_2021SEP0003/_article ]
These and other contributions by Eiichi Goto to the development of computer technology are chronicled succinctly in a web page of Japan Information Processing Society after he passed away in 2005. Interested readers are referred to the following URL.: https://museum.ipsj.or.jp/en/pioneer/gotou.html
Appendix IV: Earlier research for building computer at Takahasi laboratory
The team at Takahasi laboratory including Eiichi Goto was very interested in building a computer of their own after their study of EDSAC and other computers abroad. This article and others showed their interest in novel, reliable and low cost logic elements which would let them build a computer at the University of Tokyo, and once the parametron was invented and its reliability and ease of maintenance far exceeded both the vacuum tubes and transistors, their interest turned into building a computer using parametrons.
For example, the papers by Hidetosi Takahasi, Eiichi Goto, and Hiroshi Yamada in 1954 [1] (Hidetosi Takahasi, Eiichi Goto, Hiroshi Yamada: "On Mechanical and Electronic Calculation Methods", Technical Committee on Electronic Computers of the Institute of Electrical Communications, 1954.) and [2] (the explanatory diagram that accompanied [1]) BEFORE the invention of parametron described the approach regarding information storage that combined mechanical and electronic methods.
The paper [1] and its diagram [2] describe a "Quantum Voltage Storage Device".
The term "Quantum" is used with the meaning of "discretized" or "discrete", or "digital" in today's parlance. The authors' background in physics shows here. Takahasi was a professor at the department of physics and thus "quantum" was a familiar term to the authors.
Readers in the 21st century (in 2025) may find the description in [1] and [2] very banal. It is common knowledge today. But back in 1954, it was an important overview of information storage via electronic and legacy mechanical element (read mechanical rotating switch of the time).
With previous research like this, the laboratory members began working on building components of computers using parametron once parametron was invented and its reliability was proven.
The following is the translation of the first paragraph by the
proposer.
Please recall this was in 1954 and relay computers were still in
vogue. They actually tried to use a mechanical switch from a
university PBX for the mechanical scanning device that scans the
storage devices and restores the electric charge before the electric
charge is lost and the information is lost. Basically, they described
an electromechanical equivalent of periodic refreshing of dynamic RAM
in today's terminology.
Also, please note that the office automation would be far into the future. The paper was written manually. All the characters were hand drawn and mimemograph was used to print the paper for distribution. (Japan did not have a very efficient and compact typewriter for its characters as in English-speaking countries.)
1. Quantum Voltage Storage Device". Since the electric charge stored in a storage device hardly changes in a short period of time, it is clear that information can be stored for a short period of time. However, if left unattended for an extended period of time, the electric charge leaks out and the information is lost. To prevent this, the charging voltage of the storage device should be quantized to a discrete value, and before the information is lost, the electric voltage of the storage device should be restored to the reference discrete value by an appropriate device. A machine that has the function of restoring the charging voltage of the storage device to the standard discrete value will be called a quantizer. It is not necessary to have one quantizer Q attached to each storage device. This is because a single quantizer can be used to quantize the voltages of many storage devices by sequentially switching between them if a suitable scanning device is available. If the time that a storage device can be left without losing information is T, and the required operating time per storage element of the quantizer and switching device S is t, then one quantizer Q can handle a maximum of N = T/t storage devices. In principle, a switching machine with such a function could be electronic or mechanical. From the above point of view, the Williams Memory Tube can be regarded as an electronic storage device. A normal Flip Flop is a storage device with a distributed capacity, but without S, and each storage device can be considered to have one quantizer Q attached to it. A Whirl Wind Tube can also be thought of as having an infinite number of Qs. However, these are all purely electronic, and there seems to have been no description yet of the second possibility above, i.e., a quantum voltage storage device that uses mechanically driven electric contact switches. Therefore, we would like to examine this new storage system and its application to computers.
And the paper continued to explain the use of mechanical element. You can see the mechanical scanning of the charge device that stores information in the diagram of [2], such as in Figure 1 of the paper.
This topic was discussed as part of the team's vision of building a computer using available devices. This time for storage purposes.
For PC-1, though, the team used so-called two frequency AC-driven core memory system that used non-destructive reading method, which worked well with parametron device.
Appendix V: Speed Comparison
Here is a bit more detailed discussion on the speed than in the main text of the application.
Comparison of speeds of typical Japanese computers around the time
parametron was invented (1954) and PC-1 started operation (1958) is
shown.
The upper part is quoted verbatim from Goto's seminal paper [9] ("The Parametron, a Digital Computing Element Which Utilizes Parametric Oscillation", Proceedings of the IRE, published in 1959). It lists the speed of typical parametron-based computers of that time.
The lower part of the table is created using data taken from a table, Table 2.2 in the report of National Science Museum: "History of First and Second Generation Japanese Computers and the Preservation of (Early) Examples", Akihiko Yamada. (available online at: https://sts.kahaku.go.jp/diversity/document/system/pdf/003.pdf)
Lower part is created to mimic the original Goto's table.
Unfortunately, some numbers in National Science Museum report did not match those of Goto's table for PC-1 (the proposer trusts Goto's number), and did not match the computer built at the Osaka university. Osaka University computer development is described at https://museum.ipsj.or.jp/heritage/handai-shinkukan.html (in Japanese). The addition speed of Osaka computer machine is mentioned as 40 milliseconds there. I take the number at IPSJ site as correct. There seems to be a transcription error somewhere.
To be frank, the detailed data for machines created and operated 60-70 years ago is hard to come by.
So the proposer has to be careful, but the numbers shown for FUJIC in National Science Museum report FUJIC matches the numbers in the article written by FUJIC's inventor. So, the proposer assumes they are correct.
The above was the choice of numbers in the lower part of the table.
The table shows that PC-1 (and subsequently PC-2) did well in terms of performance, but we can also tell that transistor computers with faster operation would take over once they would became stable.
One computer worth mentioning in this application document for "Parametron, 1954" is FUJIC, built almost single-handedly by a developer, Bunji Okazaki, at Fuji Photo Film Co, Ltd. in July 1956 using vacuum tubes. (FUJIC is one of the only vacuum tube computer ever built in Japan and became the FIRST electronic computer in Japan.)
The vacuum computer FUJIC was the only machine built before PC-1 that beat the speed of PC-1 in the arithmetic (addition and multiplication).
(The proposer excludes ETL Mark III from this comparison. It used
point-contact transistors, which were no longer produced due to its
unreliability, and retired as soon as Mark IV was built. The proposer
does not believe it did any meaningful calculation as opposed to PC-1
or FUJIC. It seemed to run mostly benchmarking to calibrate the machine.
There is a very sketchy description of ETL Mark III:
Transistor Computer (ETL Mark III-VI)
https://museum.ipsj.or.jp/guide/pdf/magazine/IPSJ-MGN170212.pdf
Original Japanese title: トランジスタ計算機 ETL Mark III-VI
My intention here is to compare the practically used computers for many
applications, and ETL Mark III does not fit the bill.)
Completed in July 1956, FUJIC operated as the calculating machine for optical ray tracing for lens design at the Fuji Photo Film. Such calculation used to be done by female calculators working in a pair to compare the results for verification at the end of calculation steps.
Like MUSASINO-1, FUJIC was not used outside the company. Its operation was strictly inside although there were times some calculation jobs were contracted from outside parties. But the programming and operation seems to have been done only in Fuji Photo Film's Odawara works.
FUJIC's lifetime was much shorter than PC-1. Fuji Photo Film decided to stop the lens design in 1958 (or 1957? The description differ among documents), and handed over the operation to its subsidiary. However, because the operation of FUJIC was restricted to the original office, it seems that not enough technical expertiseexisted outside to use FUJIC. The reliability issues caused by the use of vacuum tubes made it difficult to use it, and the computer was finally donated to Waseda University in September 1958 after less than 2 and half years of operation. (Documents and records differ on how many years FUJIC operated. Okazaki mentioned that it was used two and half years and so the proposer would adopt that figure.) Okazaki, the inventor, left Fuji Photo Film in 1959, and joined NEC to pursue computer design there.
By the time PC-1 became operational in March 1958, the proposer thinks mothballing plan started for FUJIC for eventual transfer to Waseda University. That is why akahasi wrote, "currently, PC-1 is the fastest computer in Japan..." (proposer's translation) in September 1958 in [5]("On the PC-1 Parametron Computer"). FUJIC was not operational when Takahasi wrote the draft of the article because it was being transferred to Waseda University.
FUJIC was a great invention done by a person, but due to the company's decision to leave lens design, it lost backers behind its operation. It could not leave a lasting impact unlike parametron computer PC-1 used by many researchers inside and outside the University of Tokyo. Many academic papers were written about PC-1 while there is few articles that remain today about FUJIC.
References for this appendix: Memoir by the inventor of FUJIC, Bunji Okazaki:
Japan's first electronic computer FUJIC, Bunji Okazaki, Information
Processing Society of Japan, Vol 15, No. 8, August 1974.
(original title is "わが国初めての電子計算機 FUJIC")
Available online at: https://museum.ipsj.or.jp/guide/pdf/magazine/IPSJ-MGN150808.pdf
The above documents lists the time for addition/subtraction as 0.1
milliseconds, and 1.6 milliseconds (average) for multiplication, which
match the numbers in National Science Museum report.
Bunji Okazaki at Information Processing Society:
https://museum.ipsj.or.jp/en/pioneer/okazaki.html
FUJIC at Information Processing Society page:
This page lists 0.1 msec for addition/subtraction, and 1.6 milliseconds for
multiplication. The fast speed is attributed to parallel arithmetic circuits.
https://museum.ipsj.or.jp/en/computer/dawn/0010.html
History written at the website of Fujifilm Co. Ltd (in Japanese).
日本語タイトル： カメラ・工学機器事業基盤の確立
https://www.fujifilm.co.jp/corporate/aboutus/history/ayumi/dai2-09.html
There is a description about FUJIC.:
カメラのレンズには、明るく、シャープな画像を得るために、屈折率の異 なる何枚かの単体のレンズが組み合わせて用いられる。これらの組み合わ せを決め、最適のレンズを設計するためには、複雑な計算を必要とし、高 級レンズの設計には専門家でもその計算に数か月を要するほどであった。 この計算を迅速かつ正確に行なうために、当社は、電子計算機を活用する ことを計画し、1949年（昭和24年）、その設計に着手した。試行錯誤を繰 り返しながら開発を進め、1953年（昭和28年）、組み立てを開始した。長 さ4m・高さ2mのパネルの中に、計算装置・記憶装置・制御装置が1,700本 の真空管と5,000mの配線でつながれ、使用部品は実に2万個を数えた。 1956年（昭和31年）7月に完成し、“FUJIC”と命名した。
“FUJIC”は、当社のレンズ計算に貢献するとともに、気象庁や各大学からの計算依頼にも応え、国産電子計算機の第1号として注目を浴びた。
しかし、“FUJIC”は真空管式なので、その寿命の点で実用上問題を残し ていた。このため1957年（昭和32年）、レンズ部門を富士写真光機に移設 した際、“FUJIC”を研究用として早稲田大学に寄贈した。現在は、わが 国科学史上の重要な記念として東京上野の科学博物館に展示され、同所で コンピューターのその後の発展を静かに見守っている。
English Translation of the above by the proposer.:
Camera lenses use several individual lenses with different refractive indices to produce bright, sharp images. Determining the optimal combination of these lenses and designing the best lens requires complex calculations, and it used to be that even experts needed several months to complete these calculations for high-end lenses. To perform these calculations quickly and accurately, our company planned to utilize electronic computers and began design work in 1949. After repeated trials and errors, development progressed, and assembly began in 1953. Inside a panel measuring 4 meters in length and 2 meters in height residedthe computing unit, memory unit, and control unit consisting 1,700 vacuum tubes connected by5,000 meters of wiring, with a total of 20,000 parts used. It was completed in July 1956 and named “FUJIC.”
“FUJIC” contributed to our company's lens calculations and also responded to calculation requests from the Meteorological Agency and various universities, gaining attention as the first domestically produced electronic computer.
However, as a vacuum tube-based system, “FUJIC” had practical limitations due to the limited lifespan of tubes. Therefore, in 1957, when the lens department was relocated to a subsidiary which later became Fujinon of today (after a few incarnations), “FUJIC” was donated to Waseda University for research purposes. Today, it is displayed at the Science Museum in Ueno, Tokyo, as an important historical artifact in the history of science in Japan, quietly witnessing the continued evolution of computing technology.
Note: Fuji film's description state that the lens department was relocated to its subsidiary in 1957. It did not mention the donation to Waseda University that occurred in September 1958 clearly.
Reliability issues: In contrast to PC-1's parametron stability, Okazaki mentioned that he had to replace two to three vacuum tubes each day because they got broken. (Japanese interview available online at https://ascii.jp/elem/000/001/214/1214060/2/ )
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