The People's Best Friend: The Calculators' Brief History

The calculator has a long and fascinating history. From the timeless Abacus to the modern smartphone app this device has been people's most trusted friend.
Christopher McFadden

Forget dogs, people's best friend has always been, and will always be, the calculator.

This powerful yet diminutive device has undergone a few significant facelifts over the millennia but their basic functions would be familiar in concept to our ancestors.

From the simple Abacus, more advanced mechanical forms would be developed until they underwent several quantum leaps in power with the advent of the first electronics and then the microchip.

Their final and most significant advancement came with their casting off their physical shackles to become almost exclusively virtual on an incalculable number of computers and smart devices.

The calculator's physical complexity reached its zenith in the 1990s but the rise of the internet, home computers and ultimately smartphones, has already, mostly, made them obsolescent.

Whilst some, like me, do prefer to use a physical, dedicated calculator for calculations, many others never give them a second thought.

The People's Best Friend: The Calculators' Brief History
The HP-15C is one of the greatest calculators of all time.Source: eBay

But we at IE are determined to make sure you never look at that old school calculator the same way ever again. By picking it up once more you are quite literally holding thousands of years of human history in your hand - as you are about to find out.

Where it all began - The venerable Abacus

The history of the calculator, or what we know of it, began with the hand-operated Abacus in Ancient Sumeria and Egypt in around 2000-2500 BC.

These are very simple devices compared to modern calculators consisting of sets of ten beads on a series of rods held in place on a quadrilateral frame usually made of wood.

The Abacus was the first purpose-built device for counting yet discovered with the exception of the counting board.

Prior to this is likely humans used their fingers or piles of stones, seeds or beads (or anything really). 

The principle is very simple - at least for addition. The topmost rod represents the number of small units.

By moving them from one side to the other the user can quickly keep track of any unit numbers between one and ten. 

Once ten is reached a single bead on the next rod can be slid across to represent a unit of ten. The topmost beads can then be returned to the opposing side and small units can be counted again.

Each lower rod represents ever larger powers-of-ten with the third representing hundreds, the next thousands and so on. 

Chinese Abacus (Suanpan) vary in design and are used in a slightly different manner western versions, but the principle is the same.

It is believed that the Abacus was introduced to the Chinese by Roman merchants in around 190 AD.

The People's Best Friend: The Calculators' Brief History
Example of a Chinese Abacus. Source: Pixabay

The Abacus would remain as the de facto counting device for over four and half millennia.

It is still the counting device of choice throughout many parts of Asia (some devices even combining the two). 

That was, at last in Europe, until 1617.

John Napier and his fancy bones

In 1617 a Scottish Mathematician, John Napier, published his seminal book Rabdology (calculating with rods). This book described the workings of a device that would come to be known as Napier's Bones.

The bones (rods) were very thin with each being inscribed with multiplication tables. Users could make quick calculations by adjusting each rods' vertical alignment in order to read off the multiplication total in the horizontal.

They were primarily developed as a calculation method to find the products and quotients of numbers. The beauty of them was their simplicity.

After only a matter of a few hours of practice, anybody could quickly make fairly complex multiplication and division calculations. An expert could even use them to extract square roots for pretty large numbers, not bad for the 17th Century!

They enabled a user to break down multiplication into much simple addition operations or division to simple subtractions.  

As impressive as this simple invention was it was not technically speaking a calculator as the user still needed to make mental calculations in order to use them.

They did, however, offer a shortcut methodology to help speed multiplication and divisional problems.

The slide rule was the next big advancement

Europe saw the next stage in the development of Mechanical calculators during the 17th Century.

With the help of Napier and his algorithms,  Edmund Gunter, William Oughtred and others, were able to make the next significant development in calculators - the slide rule.

The slide rule was an advancement to the abacus as it consisted of a sliding stick that could perform rapid multiplications by using logarithmic scales.

The People's Best Friend: The Calculators' Brief History

On the surface, slide rules look like pretty complex devices but that betrays the pure utility of them.

They are, in effect, a sliding stick (or disk as above) that make use of logarithmic scales to quickly solve multiplication and division problems. 

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They would undergo a series of advancements that would enable them to be used to perform advanced trigonometry, logarithms, exponentials, and square roots. 

As late as the 1980s the use of slide rules was part of many countries school curricula and was considered a fundamental requirement for millions of school children to learn. 

This is quite interesting as other mechanical and electronic calculators were in existence at this time.

However, often, these were not the most portable devices when compared to the slide rules of the time that could easily fit into a breast pocket or button-down shirt. 

Slide rules were of fundamental importance to the NASA space program with them being heavily relied upon during the Apollo program.

A Pickett model N600-ES was even taken along with the crew on the Apollo-13 moon mission in 1970. 

Blaise Pascal and the rise of the true mechanical calculator

In 1642 one Blaise Pascal created a device that could perform arithmetic operations with just two numbers.

His machine comprised of geared wheels that could add and subtract two numbers directly and also multiply and divide them by repetition.

The inspiration for Pascal's calculator, arithmetic machine or Pascaline, was his frustration with the laborious nature of arithmetical calculations his father had to perform as the supervisor of taxes in Rouen.

The key part of his machine was its carry mechanism that adds 1 to 9 on one dial.

When the dial is turned to reach 0 the next dial is able to carry the 1, so on so forth. His innovation made each digit independent of the state of the others, which enabled multiple carries to rapidly cascade from one digit to another regardless of the machine's capacity.

Between 1642 and 1645 he would create no less than 50 prototypes, finally presenting his final piece to the public and dedicating it to the then chancellor of France, Pierre Seguier.

He would continue to improve his design over the next few decades and was eventually presented with a Royal privilege (the equivalent of a patent) to allow him exclusive rights to design and build mechanical calculators in France.

Today nine examples of his original machines exist with most displayed around museums in around Europe.

The People's Best Friend: The Calculators' Brief History
Pascaline's carry mechanism. Source: Wikimedia Commons

Imitation is the sincerest form of flattery

All other mechanical calculators following the Pascaline were either directly inspired by it or shared the same influences that Pascal used for his device. 

Key examples included the 1673 Leibniz Wheels, devised by Gottfried Leibniz. Leibniz attempted to improve on the Pascaline by adding automatic multiplication features to Pascal's design.

Gottfried's design consisted of a cylinder with a set of teeth of incremental lengths.

These were coupled with a counting wheel and whilst not a compete calculator in and of itself, it would become an integral component of future mechanical calculators. 

He did attempt to build his own complete calculation machine, called the "Stepped Reckoner", a few decades later but it was never mass-produced. 

Leibniz's work was not in vain, however. In 1820, Thomas de Colmar built his famous Arithmometer.

This incorporated Leibniz's wheels (step drum), or his own re-invention of it, and would go on to become the first mechanical calculator strong and reliable enough to be used day to day in places like offices. 

The People's Best Friend: The Calculators' Brief History
Source: Ezrdr/Wikimedia Commons

It would become an instant commercial success and was manufactured between 1851 and 1915. It was also copied and built by many other companies around Europe.

The calculator was capable of adding and subtracting two numbers directly and could perform long multiplications and divisions by using a movable accumulator.

The Arithmometer would mark a watershed in calculator history forcing, in its own way, the beginning of the end for the large-scale reliance on human calculators.

It would also effectively launch the mechanical calculator industry around the world. 

Some were still built and used as late as the 1970s

The rise and fall of the Mechanical Calculator age

Mechanical calculator innovation moved across the Atlantic to the USA after the success of the Arithmometer with the development of various hand-cranked adding machines.

These included the highly successful Grant Mechanical Calculating Machine built in 1877 and the famous P100 Burroughs Adding Machine devised by William Seward Burroughs in 1886.

The P100 became very successful indeed for Burroughs and his company and would be the first of a line of office calculating machines.

This would make the Burroughs family very wealthy indeed and allowed his grandson, William S. Burroughs, to enjoy a carefree lifestyle enabling him to pen several novels including the drug-culture inspired novel "The Naked Lunch". 

A little later, in 1887, Dorr. E. Felt, got a U.S. patent for his Comptometer. This machine took calculators into the push-button age and would inspire many imitations of it throughout the next century. 

The inclusion of push-buttons would dramatically improve the efficiency of calculators for addition and subtraction. This is because push button presses can add values to the accumulator as soon as they are depressed. 

This means numbers can be entered simultaneously which can make devices like the Comptometer faster to use than electronic calculators that require numbers to be inputted individually in serial.

The People's Best Friend: The Calculators' Brief History
Source: Ezrdr/Wikimedia Commons

In the late 1940's Mechanical calculators became portable. The Curta Calculator was compact, could fit in one hand, and could, rather clumsily fit into a pocket. 

In fact, it was the very first, last and only mechanical handheld pocket calculator ever developed.

It was the brainchild of Curt Herzstark (an Austrian inventor) and is effectively a descendant of Gottfried Leibniz's Stepped Reckoner and Charles Thomas' Arithmometer. 

During World War II, Herzstark completed his designs for the Curta, but as his father was Jewish, he was sent to Buchenwald Concentration Camp.

However, his mechanical know-how saved his life as the Nazi’s treated him as an “Intelligence-slave”.

It worked by accumulating values on cogs which are then themselves added or complemented by a stepped drum mechanism.

The entire mechanism fit snuggly inside a small cylinder and was, to all intent and purpose, a very beautiful piece of kit.

It was capable of addition, subtraction, multiplication, and division all in the palm of your hand. The Curta would enjoy phenomenal commercial success being the de facto portable calculator for many decades.

The People's Best Friend: The Calculators' Brief History
Type II Curta. Source:Pixabay

Each one cost around between $125 and $175 dollars and today sell for anywhere between $1000 and $2000 depending on the condition and model. 

Herzstark’s intricate design for the Curta was used all the way to the 1960s in rally cars and cockpits where quick calculations had to be made.

The Curta and push-button mechanical calculators had reached their zenith in the 1960s, but their dominance would soon be challenged.

The rise of the electronic calculator

The story of the electronic calculator has its roots in the late 1930s. As the world geared up for large-scale warfare artillery, warship gun batteries, bomb sights, and other weapons required means of calculating trigonometry quickly and reliably. 


Solutions quickly appeared like the Sperry-Norden bombsight, U.S. Navy Torpedo Data Computer, and the Kerrison Predictor AA fire control system.

These were all hybrid mechanical and electrical systems that used geared wheels and rotating cylinders to produce electronic outputs that fed into weapon systems. 

More sophisticated systems came into creation later in the war with the need to break enemy codes.

This ultimately led to the development of the famous Colossus 'computer' that was dedicated to performing XOR Boolean algorithms rather than calculations per se.

The People's Best Friend: The Calculators' Brief History
Reconstruction Colossus at Bletchley Park Source:MaltaGC/Wikimedia Commons

At the end of the war the first general calculating computer, the ENIAC (Electronic Numerical Integrator And Computer) was completed in 1946.

This was designed as a completely digital artillery firing table calculator and could also be applied to solving many other numerical problems.

This included the basic four arithmetical functions. It was 1,000 times faster than any existing electro-mechanical computer of the time and could as many as ten-digit decimal numbers in its memory.

It was, however, enormous weighing an incredible 27 tonnes and required a lot of space.

But progress in all electronic calculators hit a choke point as they were limited by the size of vacuum tubes - they would need to be miniaturized.

Miniaturization opens the door for electronic calculators

With the miniaturization of vacuum tubes, the development of electronic calculators could continue apace.

A New Inspiration To Arithmetic Accounting (ANITA) became the world's first all-electronic desktop calculator in 1961. 

ANITA was developed by the British company Control Systems Limited and used a push-button keypad for operation.

No other moving parts were required with all the clever stuff handled electronically using vacuum tubes and cold cathode "Dekatron" counting tubes. 

For a time it was the only desktop electronic calculator available with tens of thousands sold up to 1964.

The development of transistors would suddenly open up the competition. 

ANITA's dominance of the market was severely challenged by three early transistor-based electronic calculators the American Friden 130 series, the Italian IME 84, and the Sharp Compet CS10A from Japan.

Although none were significantly better then ANITA, or cheaper for that matter, their all-transistor design would open up the competition.

Companies like Canon, Mathatronics, Smith-Corona-Marchant, Sony, Toshiba would soon capitalize on this new opportunity.

Of these some notable calculators were born including Toshiba's "Toscal" BC-1411 calculator.

The BC-1411 was leagues ahead of its time and integrated an early form of RAM on separate circuit boards.

The People's Best Friend: The Calculators' Brief History
Source: Old Calculator Museum

1965 saw the introduction of the impressive Olivetti Programma 101 . This would win many industrial awards and could read and write magnetic cards, display results and had an inbuilt printer to boot.  

Around the same time, Bulgaria's Central Institute for Calculation Technologies released the ELKA 22. It weighed around 8kg and was the first ever calculator that came with a square root function.

Despite these impressive early electronic calculators, all were heavy and bulky, not to mention costly.

This was all set to change when Texas Instruments released their landmark "Cal Tech" prototype. 

It was compact enough to be handheld, could perform all the basic arithmetical functions and could even print results on paper tape. The calculator was about to go mainstream.

The microchip changed everything

The next big leap forward in calculator development came with the development of the microchip. This was no easy task and required engineerings to overcome three huge problems. 

1. The needed to replace boards of transistors with integrated microchips,

2. They needed to be energy-light so they could run on batteries rather than the mains and;

3. To be utilitarian they needed to develop slimmer, simpler control mechanisms. 

As advanced as the Texas Instruments "Cal-Tech" was it still relied on transistors and also needed to be plugged into the mains. 

Japanese and U.S. semiconductor companies began to team up to develop semiconductors. Companies like Texas Instruments teamed up with Canon, General Instrument worked with Sanyo and many other companies formed similar alliances.

After a few years of development, the Sharp QT-8D "Micro Compet" was released.

Although primitive by today's standards it used four Rockwell chips (each equivalent to 900 transistors) to power the display, decimal point, digital addition, and register input control. 

The People's Best Friend: The Calculators' Brief History
Source: Mister rf/Wikimedia Commons

This still needed to be plugged in but an alternative model, the QT-8B, used rechargeable cells that allowed it to completely portable. This was a huge innovation at the time. 

It was quickly followed by other handheld calculators the Sharp EL-8, Canon Pocketronic, and Sanyo ICC-0081 Mini Calculator. The microchip electronic calculator had arrived.

Calculators get smaller and smaller

As impressive as the calculators were they were practically obsolete at the time of their market release. Throughout the early 1970's newer and more sophisticated devices were being produced.

Some would reduce the chips needed to one in the Mostek MK6010 ("Calculator-on-a-Chip") by Busicom and later the even smaller LE-120 "Handy" that integrated an LED display and ran on 4 AA batteries

These chips would eventually be used by Intel in the first generation PCs. 

Many more would follow from American companies like Bowmar and the first slimline calculators made by Clive Sinclair in 1972.

These were all pioneers in this new growing industry but were still pretty expensive for most consumers at the time.

The People's Best Friend: The Calculators' Brief History
Source: Vintage Calculators

The LED screens also guzzled the batteries and their functions were still limited to basic arithmetic. This all changed when Sinclair produced the Cambridge that was the first low-cost calculator.

More advanced calculation capabilities were introduced to pocket-calculators with the Hewlett Packard HP-35 'scientific' calculator. This was able to handle trigonometry and algebraic functions. 

Advancements would rapidly increase almost monthly with the Texas SR-10 adding scientific notation and the SR-11 adding a Pi key and the 1974 SR-50 providing log and trig functions. 

This ultimately led to the development of the so-called 'Calculator Wars' that would ultimately see cheaper, better models being produced. A boon for consumers and a headache for manufacturers. 

By the late 1970s, the utility and popularity of the age-old slide rule had run their course.

Calculators also started to become programmable around this time with examples like the 1974 HP-65 that could handle 100 instructions, store and retrieve data from a magnetic card reader.

Heading into the 1980s companies like HP and the new kid on the block, Casio,  was leading the charge for the industry.

By the end of the 1970s, a swathe of cheap, small and low power consumption calculators could be found almost anywhere. Some were so efficient that the first solar-celled versions began to appear. 

The first, the Sharp EL-8026 and Teal Photon would mark the pinnacle in physical calculator evolution (modern ones have, in real terms, changed very little sense). Little changed throughout the 1980s with the notable exception of the development of so-called pocket computers. 

Since these were more like pocket-PCs that just calculators we won't discuss that offshoot anymore here.

But pocket-calculators, like their ancient ancestors the Abacus and slide-rule would soon need to adapt or die. The personal computer age was just over the horizon. 

The People's Best Friend: The Calculators' Brief History

Calculators become graphical and virtual

From the mid-1980s onwards calculator manufacturers were looking for any killer function that could make their products stand out from the competition.

This would ultimately lead to the development of the graphical calculator in 1985, the first being the Casio fx-7000g.

Over the next few years, other companies would improve the graphical calculator like the HP-28 in 1986. Other later models like the TI-85 or TI-86 even began to provide features like calculus. 

2D and 3D math plots began to appear as well as other features like data loggers from input sensors and WiFi/other connectivity capabilities also began to appear.

Having survived the rise of personal computers throughout the 1980s the calculator seemed "too big to fail". But a new threat was on the horizon - mobile devices!!

The first inkling of this new era came with the 1992 Bell South/IBM Simon Personal Communicator. This was a cell phone with PDA functions like email, calendar, and yes, a virtual calculator. 

Also in 1993, Apple released their Newton PDA (also featuring a virtual digital calculator) as well as others like the Palm and Handspring PDAs.

1996 saw the release of the Nokia 9000 Communicator that featured a mobile phone, PDA, internet connection which is widely considered one of the world's first smartphones.

By the mid-2000s the floodgates had opened. Blackberry, Apple iPhone, Android, and Windows Phones appeared all featuring digital calculators as standard with their OS or as free downloadable apps. 

The rest, as they say, is history. It seemed the time of the physical calculator was at an end.

Yet today, as we are all aware, physical calculators are still very popular and widely sold. The range from a couple of bucks up to several hundreds of dollars a piece. 

The People's Best Friend: The Calculators' Brief History
Source: Jen Gallardo/Flickr

Whilst devices like smartphones keep demanding high ticket prices, not to mention the pure utility and practicality of physical calculators, their future seems secure.

At least for now!

Via: calculatorcosmos magazine

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