Calculator Wars

Solid state electronic calculators appeared during the 60's as an alternative to the noisy electro-mechanical adding and calculating machines dominated by companies like Monroe, Friden and Merchant. However, the large number of transistors required to implement even the four basic arithmetic operations made these devices costly, bulky and expensive.

In 1964, for example, Sharp Corporation of Japan introduced the first transistorized calculator, the SHARP CS-10A, which weighed 55 pounds and cost $2500. Another popular system, the WANG 300, a desktop unit introduced in 1965 by Wang Corp. was priced at $1700. The world's first desktop scientific calculator, the HP9100A, introduced by Hewlett-Packard in 1968 was sold for $4900.

Kilby.jpg (11815 Byte)Therefore, it was logical that several companies would start finding ways to use the miniature integrated circuits invented in 1958 by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor as a way to produce lighter and more efficient versions of calculators.  
Some of the players involved in this quest were Texas Instruments, INTEL and Hewlett-Packard.

It was September of 1965 when Jack Kilby, one of the inventors of the Integrated Circuit, proposed to Jerry Merryman and James Van Tassel of Texas Instruments to start a project aimed to develop a miniature calculator that would perform the basic arithmetic operations and would fit in the palm of the hand.

Few years later, in 1968, Bill Hewlett instructed his engineers at Hewlett-Packard to start the design of a calculator able to handle the scientific calculations performed by slide rules and would fit in a pocket.

The idea were also growing in Japan. In June of 1969, Busicom, a Japanese manufacturer of desktop calculators approached the young INTEL, founded in 1968 by Robert Noyce, co-inventor of the Integrated Circuit, looking for a company able to produce a set of chips they have designed to manufacture electronic calculators.

The stage was set, and it was just a matter of few years until these ideas crystallized in an entirely new breed of products, microprocessors and the hand-held calculators.

Caltech_large.jpg (60490 Byte)Of course, Texas Instruments had the lead in this race, and by 1967 the Jack Kilby's team completed the development of its first prototype: the "Cal-Tech." It handled the four arithmetic functions, was packed in a small rectangular box, weighed only 45 oz. and used a thermal printer to display the results.  
The same year Texas Instruments applied for a Patent, and in June 25 of 1974 was granted the Patent 3,819,921 for a "Miniature Electronic Calculator." In December 4, 1975, the Smithsonian Institution accepted Texas Instruments donation of the "Cal-Tech" prototype.

Pocketronic.jpg (58533 Byte)While Busicom was dealing with INTEL, Texas Instruments were negotiating with Canon in Japan the production of a commercial version of their "Cal-Tech"  calculator. This version, called the "Pocketronic", was introduced by Canon in April of 1970 and sold in Japan for $395. In February of 1971, Canon introduced the "Pocketronic" in the USA with a retail price of $345.

hp-35.jpg (68918 Byte)On the other hand, Hewlett-Packard completed the development of its scientific pocket calculator in 1971, and in July of 1972 it surprised the market by launching the HP-35, the first pocket calculator able to perform complex mathematical functions. The reaction of the public to this product was spectacular even though it was priced at $395.  

Personal_60DB.jpg (81557 Byte)The Busicom attempt did not live to its expectations, however it lead INTEL into the invention of the microprocessor. As a byproduct of this project, INTEL launched its first microprocessor, the 4004, in November of 1971. Busicom used this microprocessor in their calculators but soon succumbed to the competition.  
M27.jpg (40281 Byte)In Europe, Denner & Pape, a slide rule manufacturer since 1872, also entered the market of hand held calculators by introducing in 1972, the centennial year of their first ARISTO slide rule, the ARISTO M 27 priced at 460 DM. They used the "
calculator-on-a-chip" sold by Texas Instruments.

But the war for the market of small calculators had started. In 1972, Texas Instruments, up to that point a chip provider, penetrated the market with their own calculator, the TI-2500 called the "Datamath". It was a four function calculator and was sold for $120. Then, in 1973 they launched their first scientific calculator, the SR-50, aimed to compete with the HP-35. It was priced at $170, well under the HP-35 price.

M36.jpg (65176 Byte)M75.jpg (65764 Byte)In Europe, ARISTO followed in 1973 with the ARISTO M 36, a very well designed four function calculator with a memory key, and later, in 1974, with the ARISTO M 75, a scientific calculator. 

TR1.jpg (62581 Byte)
TR1_1.jpg (68325 Byte)Faber-Castell made a last attempt to save the slide rule and combined with the TR1 both an electronic pocket calculator and a traditional slide rule. 

By 1975 Denner & Pape stopped making slide rules. Its main competitors, Faber-Castell and Keuffel & Esser did the same. The slide rule was the first significant casualty.  
By 1975 there were hundreds of companies manufacturing thousands of different models of pocket calculators all around the world. All of them used LED (Light-Emitting Diodes) luminous displays.

The competition became very fierce, prices started to drop dramatically, and many companies started to leave the field which started to be dominated by the chip manufacturers. One of these companies were Bowmar Instruments, a giant manufacturer of calculators like the famous 901B based on Texas Instruments chips, filed for bankruptcy in 1976. Denner & Pape decided to withdraw in 1978.

Another case was MITS, a company located in Albuquerque, specialized in the manufacture of calculator kits sold at $169. Thousands of these kits were sold in the USA between 1972 and 1974 However, by 1974 MITS had to close this operation because the price of fully assembled calculators were much lower than the unassembled kits.

In addition to the strong market supply, two other technical factors contributed to the reduction in prices, they were the introduction of the CMOS low energy consumption chips, and the Liquid Crystal Display devices that replaced the power hungry LED's in the second half of the 70's. These developments, not only made the calculators more efficient and cheaper, but created another shock in the already tumultuous market.

By 1990 the war of the pocket calculators was over and a few companies survived, among them were Texas Instruments and Hewlett-Packard in the USA, and Sharp Electronics and Casio, Inc. in the Japan.


Irene Kim, "Handheld Calculators: Functions at The Fingertips." Mechanical Engineering Magazine. Vol 112, No. 1, pages 56-62, Jan 1990.
G. Harry Stine, "The Untold Story of the Computer Revolution - Bits, Bytes, Bauds, and Brains. Chapter 15 - Computer in Your Pocket." Arbor House, New York.
Denner & Pape, "Graphik in Industrie und Technik." ISBN 0-387-50769-8.
Robert King, "The Evolution of Today's Calculator." The International Calculator Collector. Official Journal of the International Association of Calculator Collectors.
   Issues 15 & 16, Winter-Spring 1997
Harold A. Layer, "Micro History and Prehistory - An Archaeological Beginning," IEEE Annals of the History of Computing, Vol. 11, pages 127-130, 1989.
Bobbi A. Kerlin "From the Abacus to the Apple". Timeline of Significant Events in Information and Communications Technology."


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James Redin, February 28, 2002. No reprints without written permission.