Everyone had to use a calculator. It has already become an ordinary object that does not cause surprise. But what is the history of its development? Who invented the calculator first? What did the medieval device look and function like?

Ancient computing tools

With the beginning of trade and exchange, people began to feel the need to count. For this purpose, they used fingers and toes, grains, and stones. Around 500 BC. e. the first scores appeared. Abaci looked like a flat board on which small objects were laid out in grooves. This type of calculus became widespread in Greece and Rome.

The Chinese used 5 as the basis for counting, not 10. Suan-pan is a rectangular frame for calculations on which threads are stretched vertically. The structure was conventionally divided into 2 parts - the lower “Earth” and the upper “Sky”. The bottom balls represented ones, and the top ones represented tens.

The Slavs followed in the footsteps of their eastern neighbors, only changing the device a little. The plank counting device appeared in the 15th century. The difference from the Chinese suan-pan is that the ropes were located horizontally, and the number system was decimal.

The first mechanical device

A German mathematician and astronomer, in 1623, was able to realize his dream and became the author of a device based on a clock mechanism. Counting clocks could perform simple mathematical operations. But since the device was complex and large, it was not widely used. Johannes Keppler became the first user of the mechanism, although he believed that calculations were easier to perform mentally. From this moment the history of the calculator begins, and changes in the design and functions of the device will gradually lead it to its modern form.

The French physicist and philosopher Pascal, 20 years later, proposed a device that could count using gears. To add or subtract, you had to turn the wheel the required number of times.

In 1673, the device improved by the German mathematician Gottfried Leibniz became the first calculator - a name later cemented in history. With its help, it became possible to perform multiplication and division. However, the cost of the mechanism was high, so it was impossible to make the device available for use.

Mass production

It has been known for a long time who invented the calculator - Leibniz’s mechanism was even acquired by Peter I. His ideas were used by Wagner and Levin. After the death of the inventor, Burckhardt built a similar device, and Müller and Knutzen carried out further improvements.

The device was used for commercial purposes by the Frenchman Charles Xavier Thomas de Colmar. The entrepreneur organized serial production in 1820; his machine was almost no different from the first calculator. There was debate about which of these two scientists invented it, the Frenchman was even accused of appropriating someone else’s achievement, but the design of the calculating machine in Colmar was still different.

In Tsarist Russia, the first adding machine was the result of the work of the scientist Chernyshov. He created the device in the 50s of the 19th century, but the name was patented in 1873 by Frank Baldwin. The operating principle of a mechanical adding machine is based on cylinders and gears.

At the turn of the 19th-20th centuries, mass production of calculators began in Russia. In the Soviet Union, a device called “Felix” became widespread in the 30s of the last century and was used until the end of the 70s.

Electronic calculators

The first electronic calculator was invented by the Cassio brothers. In 1957, an era of rapid development began in the computer industry. The Casio 14-A device weighed as much as 140 kg, had an electric relay and 10 buttons. The numbers were displayed and the result was displayed. By 1965, the weight had decreased to 17 kg.

The domestic electronic calculator is the merit of scientists at Leningrad University, who developed it in 1961. The EKVM-1 model entered industrial production already in 1964. Three years later, the device was improved, it could work with trigonometric functions. The engineering calculator was first invented by Hewlett Packard in 1972.

The next stage of development is microcircuits. Who invented this generation of calculators in the USSR? 27 engineers were involved in the development. They spent about 15 years until the engineering calculator “Electronics V3-18” went on sale in 1975. Square roots, powers, logarithms and a transistor microprocessor won popular recognition, but the cost of the device was 200 rubles and not everyone could afford it.

A breakthrough in Soviet technology was the VZ-34 microcalculator. At a cost of 85 rubles, it became the first domestic home computer. Software made it possible to install not only engineering, but also gaming programs.

The MK-90 became a masterpiece of the last century. The device had no analogues at that time: a graphic display, non-volatile RAM and programming in BASIC.

22/09/98)

This article is dedicated to the indispensable assistants in our lives - microcalculators.

The history of the emergence of Soviet microcalculators, their features and interesting capabilities of individual models is described.

THE FIRST COMPUTERS

The first mechanical device in Russia to automate calculations was the abacus.

This “people's calculator” lasted in the workplaces of cashiers in stores until the mid-nineties. It is interesting to note that in the 1986 textbook "Trading Calculations" an entire chapter is devoted to abacus calculation methods.

Along with abacus, in scientific circles, since pre-revolutionary times, slide rules have been successfully used, which from the 17th century served “faithfully and truly” practically unchanged until the advent of calculators.
This adding machine could perform four arithmetic operations - addition, subtraction, multiplication and division. In later models, for example, "Felix-M", you can see sliders to indicate the position of the comma and a lever to shift the carriage. To perform calculations, it was necessary to turn the handle - once for addition or subtraction, and several times for multiplication and division.

Of course, you can turn the knob once, and it’s even interesting, but what if you work as an accountant, and you need to produce hundreds per day? simple operations? And the noise from the spinning counter gears is quite noticeable, especially if several people are working in the room with adding machines at the same time.
However, over time, turning the handle began to get boring, and the human mind invented electric calculating machines that performed arithmetic operations automatically or semi-automatically. On the right is an image of the VMM-2 multi-key computer, which was popular in the 50s (Commodity Dictionary, Volume VIII, 1960). This model had nine digits and worked up to the 17th order. It had dimensions of 440x330x240 mm and a weight of 23 kilograms.

Still, science took its toll. In the post-war years, electronics began to develop rapidly and the first computers appeared - electronic computers (computers). By the beginning of the 60s, a huge gap had formed in many respects between computers and the most powerful keyboard-based computers, despite the appearance of Soviet relay computers “Vilnius” and “Vyatka” (1961).
But by that time, one of the world's first desktop keyboard computers, which used small-sized semiconductor elements and ferrite cores, had already been designed at Leningrad University. A working prototype of this computer, an electronic keyboard computer, was also made.
In general, it is believed that the first mass-produced electronic calculator appeared in England in 1963. His circuit was made on printed circuit boards and contained several thousand transistors alone. The size of such a calculator was like that of a typewriter, and it only performed arithmetic operations with multi-digit numbers. On the left is the "Electronics" calculator - a typical representative of calculators of this generation.

The distribution of desktop computers began in 1964, when serial production of the Vega computer was mastered in our country and production of desktop computers began in a number of other countries. In 1967, EDVM-11 (electronic ten-key computer) appeared - the first computer in our country that automatically calculated trigonometric functions.

Further development computer technology is inextricably linked with the achievements of microelectronics. At the end of the 50s, technology was developed for the production of integrated circuits containing groups of interconnected electronic elements, and already in 1961 the first model of a computer based on integrated circuits appeared, which was 48 times less in mass and 150 times less in volume than semiconductor computers that performed the same functions. In 1965, the first computers based on integrated circuits appeared. Around the same time, the first portable computers on LSIs (just introduced into production) with autonomous power supply from built-in batteries appeared. In 1971, the dimensions of the computers became “pocket”; in 1972, electronic computers of the scientific and technical type appeared with subroutines for calculating elementary functions, additional memory registers and with the representation of numbers both in natural form and in floating point form in the widest range numbers.
The development of EKVM production in our country went in parallel with its development in other most industrialized countries of the world. In 1970, the first samples of IC-based computers appeared; in 1971, production of machines of the Iskra series began using these elements. In 1972, the first domestic microcomputers based on LSIs began to be produced.

FIRST SOVIET POCKET CALCULATOR

The first Soviet desktop calculators, which appeared in 1971, quickly gained popularity. LSI-based computers worked quietly, consumed little energy, and calculated quickly and accurately. The cost of microcircuits was rapidly decreasing, and one could think about creating a pocket-sized MK, the price of which would be affordable for the general consumer.
In August 1973, the electronics industry of our country set the task of creating an electronic pocket computer on a microprocessor LSI and with a liquid crystal display in one year. A group of 27 people worked on this difficult task.
After five months of work, the first samples of the MK were ready, and nine months later, three months before the deadline, an electronic pocket computer called “Electronics B3-04” was handed over to the state commission. Already at the beginning of 1974, the electronic gnome went on sale. It was a great labor victory that showed the capabilities of our electronics industry.

This microcalculator was the first to use a liquid crystal indicator, with the numbers depicted as white characters on a black background (see figure).
The calculator was turned on by pressing the shutter, after which the lid opened and the calculator began to work.
The microcalculator had a very interesting operating algorithm. In order to calculate (20-8+7) it was necessary to press the keys | C | 20 | += | 8 | -= | 7 | += |.
Result: 5. If the result needs to be multiplied, say, by three, then the calculations can be continued by pressing the keys: | X | 3 | += |.

Key | K | used to calculate with a constant.

This calculator used transparent boards with volumetric mounting. The figure shows part of the microcalculator board.
The microcalculator contains four microcircuits - a 23-bit shift register K145AP1, an indicator control device K145PP1, an operational register K145IP2 and a microprocessor K145IP1. The voltage conversion block uses a level conversion chip.

It is interesting to note that this calculator was powered by one AA battery (A316 "Kvant", "Uran").

THE FIRST SOVIET MICRO CALCULATORS

In the early 70s, the language that is familiar today for working with microcalculators was just emerging. The first models of microcalculators could generally have their own operating language, and you had to learn how to count on a calculator. Let's take, for example, the first calculator of the Leningrad plant "Svetlana" of the "C" series. This is a S3-07 calculator. By the way, it is worth noting that the calculators from the Svetlana plant generally stand apart. A small digression. All microcalculators in those days received the general designation “B3” (the number three at the end, and not the letter “Z”, as many believed). Tabletop Digital Watch received the letters B2, electronic wrist ones - B5 (for example, B5-207), desktop electronic ones with a vacuum indicator - B6, large wall-mounted ones - B7, and so on. Letter "B" - "

So, let’s take, for example, the C3-07 calculator. A very amazing calculator, especially its keyboard and display. As you can see from the picture, not only the keys are combined on the calculator | += | and | -= |, but also multiply/divide | X -:- |.
Try to figure out for yourself how to multiply and divide on this calculator. Hint: the calculator does not accept two presses on one key, only one is possible.

The answer is no less surprising: to perform, say, multiplication of 2 by 3, you need to press the keys | 2 | X-:- | 3 | += |, and to divide 2 by 3, you need to press the keys: | 2 | X-:- | 3 | -= |. Addition and subtraction occurs similarly to the B3-04 calculator, that is, obtaining the difference 2 - 3 will be calculated as follows: | 2 | += | 3 | -= |. In some models of this calculator you can also find an amazing eight-segment indicator.

Speaking about the language of working with microcalculators of the first releases, we should also mention the B3-02, B3-05 and B3-05M calculators. These are milestones of the old Iskra type calculators. In these calculators, during calculations, all indicator digits are constantly lit. Mostly, of course, zeros.

It is very inconvenient to find the first (and even the last) significant digit on such calculators. By the way, in the C3-07 model, which was mentioned earlier, there was already an attempt to solve this problem, although in a somewhat unusual way - on this calculator the zero has half the height. So, these three calculators had a very inconvenient, but quite understandable feature for early calculators: the required accuracy of calculations is set when entering the first number. That is, if it is necessary, say, to calculate the quotient of dividing 23 by 32 accurate to three decimal places, then the number 23 must be entered with three decimal places: | 23,000 | -:- | 32 | = | (0.718). Until the operator presses the reset button, all subsequent calculations will be performed with three decimal places, and the decimal point will not move anywhere at all. This, by the way, is called “fixed point,” and later calculators, in which the point already moves across the display, were then called “floating point.” Now, there have been changes in terminology, as a result of which "floating point" is now called a display of a number with a mantissa on the left and an order on the right. A year after the development of the first pocket microcalculator B3-04, new, more advanced models of pocket microcalculators appeared. These are models B3-09M, B3-14 and B3-14M. These calculators were made on one K145IK2 processor chip and one phase generator chip. The B3-09M calculator is shown on the left; the B3-14M is made in the same case; on the right is the B3-14.
These models already had a “standard” language for working on calculators, including calculations with a constant.
These calculators could already operate either from a power supply or from four (B3-09M, B3-14M) or three (B3-14) AA elements.
Although these calculators are made on the same chip, they have different functionality. And in general, “removing” various functions was inherent in many models of Soviet microcalculators. For example, the B3-09M microcalculator did not have a sign for calculating the square root, and the B3-14M did not know how to calculate percentages. The special feature of these was that the comma occupied a separate digit. This is very convenient for quickly reading information, but the last sign digit disappears. For these same calculators, before starting work, you must press the “C” key to clear the registers.

FIRST SOVIET ENGINEERING MICRO CALCULATOR

The next huge step in the history of the development of microcalculators was the appearance of the first Soviet engineering microcalculator. At the end of 1975, the first engineering microcalculator B3-18 was created in the Soviet Union. As the magazine “Science and Life” 10, 1976 wrote about this in the article “Fantastic Electronics”: “... this calculator has crossed the Rubicon of arithmetic, its mathematical education has stepped into trigonometry and algebra. “Electronics B3-18” can instantly raise square and extract the square root, raise it to any power within eight digits in two steps, calculate reciprocals, calculate logarithms and antilogarithms, trigonometric functions...", "...when you see how a machine that has just instantly added huge numbers, spends a few seconds to perform some algebraic or trigonometric operation, you can’t help but think about the big work that goes on inside the small box before the result lights up on its indicator.”
And indeed, a huge amount of work has been done.
It was possible to fit 45,000 transistors, resistors, capacitors and conductors into a single crystal measuring 5 x 5.2 mm, that is, fifty televisions of that time were crammed into one cell of an arithmetic notebook! However, the price of such a calculator was considerable - 220 rubles in 1978. For example, an engineer after graduating from college in those days received 120 rubles a month.
But the purchase was worth it. Now you don’t have to think about how not to knock down the slide rule slider, you don’t have to worry about the error, you can throw logarithm tables on the shelf.

So, a lot of work has been done, a lot of effort has been spent, and the result is a good, but very expensive calculator. To make the calculator accessible to the masses, it was decided to make a cheaper model based on the B3-18A calculator. In order not to reinvent the wheel, our engineers took the easiest path. They took and removed the prefix function key "F" from the calculator.

The calculator turned into a regular one, was named "B3-25A" and became available to the general public. And only calculator developers and repairmen knew the secret of remaking the B3-25A.

FURTHER DEVELOPMENT OF MICRO CALCULATORS

Immediately after the B3-18 calculator, together with engineers from the GDR, the B3-19M microcalculator was released. This calculator used the so-called “reverse Polish notation”.

First, the first number is typed, then the key to enter a number on the stack is pressed, then the second number, and only after that the required operation. The stack in the calculator consists of three registers - X, Y and Z. In the same calculator, entering the order of a number and displaying the number in floating point format (with mantissa and order) were used for the first time. The calculator used a 12-digit indicator with red light-emitting diodes.

Based on the B3-26 calculator, the B3-23 calculators with percentages, B3-23A with square roots, and B3-24G with memory were made. By the way, the B3-23A calculator subsequently became the cheapest Soviet calculator with a price of only 18 rubles. The B3-26 soon became known as the MK-26 and its half-brother MK-57 and MK-57A appeared with similar functions.

The Svetlanovsky plant also pleased with its model C3-27, which, however, did not catch on, and it was soon replaced by the very popular and cheap model C3-33 (MK-33).

Another direction in the development of microcalculators was the engineering B3-35 (MK-35) and B3-36 (MK-36). The B3-35 differed from the B3-36 in its simpler design and cost five rubles less. These microcalculators were able to convert degrees to radians and vice versa, multiply and divide numbers in memory.
It was very interesting that these calculators calculated the factorial - by simple search. It took more than five seconds to calculate the maximum factorial value of 69 on the B3-35 microcalculator.
These calculators were very popular among us, although they had, in my opinion, some drawback: they showed exactly as many significant digits on the indicator as stated in the instructions. Usually there are five or six of them for transcendental functions.

Based on these calculators, a desktop version of the MK-45 was made.

By the way, many pocket engineering calculators have their desktop brothers. These are calculators MK-41 (S3-15), MKSh-2 (B3-30), MK-45 (B3-35, B3-36).

The MKSh-2 calculator is the only “school” calculator produced by our industry, with the exception of large demonstration ones, which will be discussed below.
This calculator, like the B3-32 calculator (in the figure on the left), was able to calculate the roots of a quadratic equation and find the roots of a system of equations with two unknowns. The design of this calculator is completely identical to the B3-14 calculator.
Despite the ability to work with numbers with large orders of magnitude, this calculator used an eight-digit display, the same as in the B3-14. It turned out that if you display a number with a mantissa and an order, then only five significant digits will fit on the indicator. To solve this problem, the "CN" key was used in the microcalculator. If, for example, the result of the calculation was the number 1.2345678e-12, then it was displayed on the indicator as 1.2345-12.

Clicking | F | CN |, we see 12345678 on the indicator. The comma goes out.

This article is dedicated to the history of the development of Soviet calculators - from abacus to programmable devices. From the beginning of the century to the present day.

The abacus is the first automatic device used in Russia for computing purposes. This device became the “national calculator” and was used until the mid-90s. Interestingly, the "Trading Calculators" manual, published in 1986, devotes an entire chapter to calculation methods using abacuses.

The most popular mechanical calculator in the USSR was called "Iron Felix". An adding machine based on the Odhner system.

The adding machine could do four arithmetic operations - addition, subtraction, multiplication and division. “Advanced” models, for example, the Felisk-M model, had the ability to work with fractions. In order to perform calculations, the necessary numbers were dialed with levers, and the action was performed by turning the knob. One turn is for addition or subtraction, and several for division and multiplication. In the 50s, electrically driven devices appeared, which have survived to this day. Remember the mechanical cash register that is found in every third grocery store today. After the Second World War, Soviet scientists began to work closely on the development of electronic computing devices. In 1961, Leningrad University developed the first Soviet electronic calculator EKVM-1. It was one of the first electronic calculators in the world. Since 1964, mass production of such devices began, and in 1967 a calculator with trigonometric functions appeared. These devices were originally based on vacuum tubes

However, let's return to calculators. In 1971, the first calculator assembled on microcircuits was developed and put into production in the Soviet Union. A series of single-chip ALUs was developed, which was then used for almost 15 years in various models of calculators with LED displays. This is a critical moment in the development of the calculator. From a massive box powered by a lighting network, it had to step into a small, pocket-sized enclosure powered by batteries. A group of 27 engineers worked on its development. This was a huge project that involved the development of a chip consisting of 3400 transistors on a 5x5 mm chip.

After five months of work, the first prototypes of the calculator were ready and handed over to the state commission, the Electronics B3-04 calculator went on sale. The calculator had a transparent LCD screen and, most interestingly, was powered by one 1.5 volt AA battery.

The next significant step in the development of the Soviet electronics industry was the VZ-18 engineering calculator, developed in 1975.

He could take square roots, raise numbers to powers, calculate logarithms, and much more. It contained a microprocessor consisting of more than 45,000 transistors. The device was quite expensive - it cost about 200 rubles, and this is with the average salary of an engineer being 120 rubles. However, he was wildly popular.

The first programmable calculator VZ-21 was developed in 1977.

The device could perform a certain sequence of pre-programmed actions. In management I used “reverse Polish notation” and cost as much as 350 rubles. The program could consist of 60 steps and use conditional jumps and subroutines. There was a modification of this calculator for conducting experiments. This model had an externally mounted memory register that could be connected to an external device.

However, the VZ-34 became a truly popular apparatus.

It appeared in 1980. It had a green display and cost 85 rubles. It was a breakthrough. In fact it was the first home computer. There was a lot of software for it - from engineering to gaming. In the mid-80s, there was a real boom in programs for this model in the USSR. By the way, from the same time it began to be called MK-52 and received a black body. The popularity and reliability of this device was such that it was used at the SOYUZ TM-7 orbital station as an emergency computer.

And finally, a masterpiece of the calculator industry - MK-90. Nothing like this was produced in the world at that time. Calculator with graphic display, non-volatile RAM and BASIC interpreter!

It used a processor with the PDP-11 instruction system.

I can tell you from experience - a very useful device. At one time, as a student, I used it not only for calculations, but also as a universal cheat sheet for exams. 32 kilobytes of non-volatile memory made it possible to write almost the entire course of the subject into it in a short form. Unfortunately, the era of the USSR was approaching its collapse, and this device did not receive further development. It's a pity. After all, this and all the other devices that I talked about in the article were the first in the world at one time. Strange as it may seem, the USSR was the leader in the global “calculator industry” until the early 90s. Who knows? Maybe if it weren’t for the collapse of the USSR, the legendary Palm Pilot would have been called MK-xxxx?

Sergey Frolov

While collecting domestic computer equipment, I was always interested to know whether domestic calculators and other calculating machines have foreign analogues.
I had to spend a lot of time learning about these analogues. This turned out to be quite difficult: I had to spend long evenings on the Internet, thoroughly review sites where other collectors show their exhibits, write down the names of models, save images of equipment and compare them with domestic equipment.
In addition to collectors' websites, the well-known online auction Ebay, where all sorts of gizmos are sold, and, of course, calculators and other counting equipment, was very helpful in finding analogues. Navigating Ebay is especially time-consuming because sellers don't bother much. detailed description of the product being sold, often limited general description like "Vintage calculator", etc. But the most difficult thing among all this was not only the search for analogues, but also getting such an analogue into the collection. Pay attention to the photographs presented: there are both photographs of analogues from other sites, the owners of which kindly allowed the use of photographs, and my own photographs for analogues of domestic cars, which I still managed to purchase. Mass copying of computer technology most likely began with our Odhner adding machine. Here's from this model:

This is the first mass adding machine of the Odhner system, released in 1890. Before this, a trial version of a slightly different shape was released in a batch of 50 copies, but it was this model that became truly widespread and a role model throughout the world.
To get an idea of ​​the clones of the Odhner system adding machine, look at the adding machines of very famous brands, presented on the wonderful website Rechenmaschinen-Illustrated: Brunsviga, Facit, Hamann-Manus, Swedish production of adding machines under the brand name "Original-Odhner", Thales and Triumphator.
At first, foreign companies received the rights to produce adding machines from Odner and his descendants, but after the revolution, hardly anyone began to pay licensing fees to the Soviet government. Accordingly, the Soviet Union also began to copy Western analogues.
In general, there is a very big advantage to copying: it saves a lot of time on developing and debugging new technologies, and the money saved can be spent on something more necessary. Below you can look at photographs of domestic calculating machines and their foreign analogues. By and large, the photographs speak for themselves, requiring no comment, but for some cars I will make a few remarks.
For each model of calculators, I also provided links to sites where you can see more photographs of analogues (the topmost link leads to my website with photographs of the domestic version).

Bystrica and Bystrica 2 - Bohn Contex Model 20

Thanks Prof. Dr. C.-M.Hamann

A very original calculator, powered by a palm strike.

Thanks to Freddy Haeghens for submitting the photo.

The closest analogue of the Odner adding machine and, probably, the last of the adding machines sold in the USSR (late 70s). We had two options: mechanical BK-1 (Facit TK) and electromechanical BK-2 (Facit EK).
In addition, BK-3 and BK-4 were also produced, but it has not yet been possible to find out what kind of calculators they are.

Sharp Compet CS-30A - Electronics DD

Thanks to Tony Epton for submitting the photo.

By the way, this calculator has one feature: it does not contain negative numbers. If you subtract three from two, but all nines appear on the indicator - a representation of the number in complementary code.

T3-16 - HP 9100B The first desktop calculator with engineering functions and programmability from Hewlett Packard was called the HP 9100A. It appeared in 1968. Our copy was called "Electronics 70", and, judging by the name, appeared in 1970. It was a very complex calculator. For its release, the production of special transistors, analogues of which were used in the HP 9100A, was mastered. I talked to a person who used Elektronika 70 a little. He said that it was a unique calculator, which had all the tracks gilded printed circuit board. Unfortunately, I was unable to get hold of Elektronika 70 and cannot show photographs of it.
But I managed to get "Electronics T3-16", which was made on the basis of the HP 9100B. In fact, the HP 9100B was an improved version of the HP 9100A.
If you go to the site where I took photographs of the T3-16 (http://www.leningrad.su/museum/show_calc.php?n=211), you can see how complex this calculator is: a large number of microcircuits, memory on magnetic cores , a magnetic card reader where user programs were stored, a cathode ray tube where information was displayed, and so on. Of course this one small computer It turned out to be very difficult to manufacture and operate, and it could not be produced in large quantities.

Electronics 24-71 - Sharp QT-8D

Calculators in general were pioneers in electronics. New technologies were mastered for their microcircuits, new types of indicators were produced. For example, in this model, for the first time in the USSR, a vacuum luminescent indicator of the IV-1 type (number sign and overflow) and IV-2 (digits) was used. Pay attention to the silhouette of the signs. It is unique to this micro calculator and has not been used anywhere else. All products with indicators on glowing green numbers started with this calculator model.

Electronics B3-04 - Sharp EL-805

The first domestic pocket microcalculator. Gold glass board. 1974. In six months, we managed to completely copy its analogue, the Sharp EL-805: develop microcircuits from scratch, master liquid crystal technology, and so on. There is only a slight difference in the two models - in the shape of the lid covering the indicator (visible in the photo).
The microcalculator turned out to be very unreliable and practically unrepairable. The machines of the first releases were called “Microcomputers”, and on later ones the term “Microcalculator” was first used.

Electronics B3-18 - Anita 202SR
Electronics B3-18A - Rockwell 61R

Around the same time as with B3-04, the question arose about creating an engineering calculator. Our industry took two paths and almost simultaneously released the first two domestic engineering calculators: Electronics S3-15 and B3-18. There were two ways: we made the first calculator ourselves, involving leading mathematicians to compile algorithms for calculating functions, and the second became a copy of the Anita 202SR calculator.

A year later, a modification of the B3-18 was released called B3-18A (Rockwell 61R)

A copy was made, but problems arose: the calculator chip required precise adjustment of the supply voltage. On each chip they wrote (mostly with a pencil) the operating voltage of the microcircuit with an accuracy of hundredths of a volt!

Electronics B3-23 - EZ2000

Except full copy calculators (including control chips) and copying of the design was used. This can be seen in the example of calculators Electronics B3-23 (EZ2000), B3-02 (Sharp EL-8001), B3-11 (ICC-82D) and MK-85 (Casio fx-700P), but more on the latter below.

As I already wrote, for the first domestic microcalculator Electronics B3-04, the Sharp EL-805 was taken as the prototype as the first liquid crystal calculator. And the Electronics B3-30 microcalculator was also taken from the first liquid crystal calculator, but with a slightly different technology - black symbols on a light background - the same one that is now installed in almost all models. That same model was called Sharp EL-8020.

For a long time, another well-known collector of domestic calculators, Australian Andrew Davie, and I believed that one of the most beautiful calculators in terms of design was the Electronics B3-36. But recently I managed to get my hands on its prototype - a rather rare Rockwell THE 74K calculator.

As you can see, the design is repeated almost completely, and the functions of the calculator are 100 percent identical.

B3-35 - Hanimex ESR Master

The same can be said about Electronics B3-35 calculators (Hanimex ESR Master). This model differs from the B3-36 almost only in design.

B3-38 - Casio fx-48

To date, I have not been able to get my hands on a Casio fx-48 calculator. Shown here is a photo taken from an Ebay auction many years ago. This is the smallest domestic microcalculator. It was taken from a Casio fx-48.

MK-51 - Casio fx-2500

Around the same time, one of the most popular microcalculators was made - Electronics MK 51 (Casio fx-2500). What is most interesting is that the same chip is used for Electronics B3-38 and MK-51. The fact is that Casio very widely uses technology when the same processor chip is used to produce calculators and a large one is produced for it. the lineup calculators. If you have an MK-51 calculator, you can check interesting fact, that if you press the F key and the number key, the function that is drawn for the F1 key on the B3-38 calculator will be executed.

MK-71 - Casio fx-950

The same can be said about the Electronics MK-71 (Casio fx-950) calculators. Casio has a similar model with an 8-digit indicator instead of a 10-digit one. It's called Casio fx-900. That model does not have a lever for switching the calculation mode trigonometric functions and the selection of degrees-grads-radians is performed using buttons. And the most interesting thing is that you can go from fx-950 to fx-900 by setting this lever to an intermediate position - between degrees and radians or between radians and degrees. I checked - it works on both the MK-71 and the Casio fx-950.

MK-53 - Monroe M112

There are some problems with this calculator. Monroe, although it produced calculators, I am not sure that this calculator was developed by Monroe. The fact is that many companies that produced calculators either used ready-made calculator chips, or used OEM versions of other companies and put only their logos. Most likely this model was made from some kind of Sharp calculator. It is unlikely that this is a Casio, because on Casio calculators the minus sign is located to the left of the number, and on Sharp calculators it is on a separate familiar place (in this model, on the left side of the display). This calculator is also the only calculator in the USSR with a clock and a stopwatch. MK-87 does not count, because there is a separate calculator and a separate clock.

And now the most interesting thing - personal computers. The most famous calculator with BASIC - Electronics MK-85 also has its own prototype. This is the Casio FX-700P. However, the task is to do full copy FX-700P was not installed. One of the reasons was the lack of Cyrillic on the keyboard. But they still set the task - to make a complete copy as per appearance, and by built-in functions.
In the same way, at one time an exact copy of the Wang 2000 computer (Iskra 226) was made in order to be able to run programs developed for Wang, which were available in large quantities.

MK-85M - Casio fx-700P

Development was difficult; we had to tinker a lot with the indicator to achieve an acceptable level and uniformity of contrast. Still, we managed to make the MK-85, and this machine was a success.
Of course, there were some drawbacks. One of them was terrible performance. As one person who took part in the development of this model told me, the difficulty was that the calculation of functions was carried out by series expansion, while in the fx-700P it was done using the “digit by digit” method. And another factor that affected performance was the storage of numbers: in hexadecimal form in the MK-85 and in decimal form in the FX-700P.
The MK-85 uses a 16-bit microprocessor, the instruction system is compatible with the DEC PDP-11. Casio has a 4-bit processor designed to process one digit of a number. Maybe this also affected the speed of calculations.

MK-87 - Casio PF-3000

This is a very rare calculator. Only about 6,000-8,000 thousand copies were produced. A production line was purchased from Japan touch buttons, pressed by a light touch. The result was a very complex and very expensive notebook calculator with a 16-bit microprocessor. Its cost turned out to be more than a hundred rubles, and the matter did not go beyond the experimental batch.
Its prototype is the first calculator-notebook from Casio - the PF-3000 is slightly different, but in general these are machines with the same functions.

And finally, I want to say about the MK-90/MK-92. Although this calculator and the MK-90 are calculators of our own domestic design, some design details are borrowed from the Casio PB-410, especially external cartridges for storing battery-powered programs. The MK-92 with its color plotter is very similar to the Casio FA-10. It's a pity that we couldn't connect the MK-92 to the TV.

That's all. But don’t think that we were only copying Western analogues. We also produced our own calculators. Take MK-61, MK-52 for example. It would seem a simple design, but the programming capabilities turned out to be at a high level, and these calculators became the most popular.
Don't think that we were the only ones who copied from others. Industrial espionage and the use of each other's advanced technologies are standard practice among competing powers. A very clear example of the use of our technologies is the American F-15 aircraft. It is very similar to our MiG-25. But that's a completely different story.

Thank you for your attention.

Text, photographs - Sergey Frolov

Iron Ghosts of the Past - 2008

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