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Dr. Eiichi Goto









Japan, 1954

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(righthand side Dr. Goto)


The PC-1 (Parametron Computer 1) is  developed at the Professor Hidetosi Takahasi's Laboratory of the Department of Physics, University of Tokyo, in March 1958.

The Parametron is invented by Dr. Eiichi Goto while being a post graduate school student in 1954.

The Parametron is cheap and reliable, and in use widely in Japan. But it becomes defeated by the transistor based computers because of the much higher speed.

The PC-1 is a binary, single-address computer using a   Parametron with magnetic core memory.

Its architecture is based on the EDSAC computer, but its instruction set or instruction format is very different and more advanced.

The PC-1 is famous for its initial order - also known as bootstrap (ed.) -  which installs via a program on a paper tape written in symbols into the memory. (3)

It took charge of decimal to binary conversion, code conversion, the process of relative and absolute address, and so on in only 68 words. The PC-1 bootstrap is undoubtedly one of the masterpieces of computer programs in the world. It is worth to have a look at it.


Principle of Parametron

The principle of the Parametron is invented by Dr. Eiich Goto(2) in 1954 and is based on the phase of an oscillation where a constant cycle is generated.
By actuating (touching)  this oscillating "wave" on the right moment you could use the pulse generated as a minimum or maximum indication.
The phase thus rotated 0 or 180 degrees and in that way the "oscillation" can be interpreted as a binary 0 or 1. A way for encoding information.

What Goto did was to build a circuitry based on that idea, and by joining a number of such circuits one could build logical modules acting like AND - OR XOR etc.

Because of the much simpler construction the Parametron computer was much more stable than the western machines with valves and transistors. Machines build that way are also much cheaper.
It is only because of the speed of the transistor that the Parametron will loose the battle to the commercial market. Unles one finds a way to switch much more quicly.

However development does continue in universities when we may believe the various web pages.


Start September 1957
Completion March 1958
Close May 1964
Parametron 4.200
Memory magnetic core 512 words(short),256words(long)
Addition/subtraction 0,4ms
Multiplication 2,6ms(short), 4,4ms(long)
Division 16,1ms(short/long)
Clock pulse 10kHz
Input photoelectric paper tape reader
Output tele-typewriter


The principle of the Parametron is invented by Dr. Eiichi Goto(2) (see top picture)

March Oi Electric Co., Ltd. Shows Prototype Aleph Zero Electronic Calculator [Parametron (ferro-electronic) Circu

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Parametron X_aleph_01


A New Approach to Josephson Junction Logic

The direct current flux Parametron using Josephson junction and based on the principle of Parametron seems to be the answer for the search of new technology for the future needs of computer power. The combination of its very high switching speed and highly integrable Josephson junction with the established Parametron computer technology accounts for its high performance. This book presents the new type of Josephson computer technology which is fundamentally different from the conventional approach. In this approach, a logic state is represented by a flux polarity whereas the conventional approach uses a voltage state to represent a logic state.


Go Backhardware index Last Updated on 29 September 2000 For suggestions please mail the editors 

Footnotes & References

1 by K F Loe & E Goto (Tokyo)
2 A New Concept in Computing, by R. L Wigington, Proceedings of the IRE, April 1959, Vol 47, No 4, page 516-523.
3 This is probably one of the first Operating Systems. (ed.)