"Red" Calculators

by Kenton Green


Although the information and pictures presented here is gleaned from various sources and their reminisces (for which I express my deepest gratitude), I am responsible for the errors and inaccuracies. This article contains known discrepancies and incomplete data, for example, some calculators thought to be of primarily Soviet design and construction, but for which not enough information existed to include in this article, are the B3-23, B3-24(G) and C3-27. If you have corrections, please contact me.
Imagine the fearsome problem faced by the State Committee of the USSR in 1973; how to avoid falling hopelessly behind the West's burgeoning integrated circuit industry. A senior State Committee member stood up in front of the assembly and with a grave face displayed a small plastic box not much larger than a pack of cigarettes. This device, he said, is a pocket calculator, and we must be able to mass produce them cheaply for our citizenry, if we hope to stay competitive with Western science and technology. Pocket-sized electronic calculators, he went on to explain, were sweeping the Western world and revolutionizing every calculation, from checkbook balancing to lunar launch trajectories.

Truth be told, these little wonders were already sweeping the Communist world as well; a thriving gray market was busily filling the demands of defense industry scientists and wealthier academic faculty members for smuggled "electronic slide rules" from Western Europe and the USA. Dependency on Western technological proficiency was a very real fear.

It was under these auspices, in August of 1973, that the State Committee gave 27 engineers from the Ministry of Electronics a 12 month deadline: develop a working prototype of a hand-held electronic calculator that can be manufactured in the Soviet Union! These men worked long hours under alot of pressure, and what they presented to the Committee nine months later would come to be known as the "Elektronika B3-04."

It is not currently, and may never be, known just how much independent design went into this (and later) "Soviet" calculators, and how much was "reverse-engineered" or just plain stolen. Due to possible lost-royalty claims, nationalistic propaganda and touchy issues of the international observation of Geneva Convention copyright laws, details of USSR design procedures are scant. What is known, or at least can be observed, is the similarity of various Soviet electronic devices to Western and Asian designs.

The B3-04, for example, bears a striking resemblance to the early Sharp LCD calculator, the EL-805. The fact that this initial offering by the Communist nation, not known for its technological prowess, had an ultra-state-of-the-art LCD display raises obvious questions as to the originality of the design. And since subsequent calculators fell back on more conventional LED and vacuum luminescent (VL) displays until LCDs reappeared 5 years later, suspicions of Soviet reliance on imported techniques are only heightened. This calculator, identical the Sharp EL-805, performed the standard four functions and used "arithmetic" logic, e.g. to compute 4-1, one must press [4],[+/=],[1],[-/=] instead of the later-developed algebraic logic of [4],[-],[1],[=]. Other aspects of the calculator, though, do point to at least some domestic design. The circuit board for this calculator looks different than the Sharp unit, and used the so-called Big Integration Schematic (BIS) (similar to our Large Scale Integration, LSI) which could place 3,400 transistors on a 5x5 mm^2 silicon chip.

This article focuses on the time frame when hand-held calculators were primarily designed and/or made in Russia, spanning the mid-70's to mid-80's. There were however calculators partially or completely designed in other parts of the USSR. These included the Elka, of Bulgarian design, the MiniReks MR series that came from East Germany (but of West German design) in 1973, and the Czechoslovakian Tesla Corporation's OKU line of calculators in 1977. Within Russia, besides the Elektronika calculators made by the Soviet Ministry of Electronics, there were some small computers and calculators of the "Iskra" line manufactured by the Ministry of Instrumentation.

The first Soviet-made hand-held calculator, as mentioned, was the B3-04, and it began production in 1974, shortly after approval by the Committee. The production run for this grand-daddy extended just into the 80's, by which time production volume had risen and price fallen an order of magnitude. This time period also nearly spans the hey-day of the "Soviet calculator"; production was mostly given over to Asia after roughly the mid-80's, as I will mention later.

During this era of "Built in the USSR," quality was very sporadic; bad solder joints, weak IC boards and uneven material processing gave the calculators a reputation for high "infant mortality"; many would quietly die within a month or two of manufacture, and with little hope for warranty repair. The flip side of this, though, was that factors such as thick board traces, low transistor- and circuit-density, and large, heavy-duty, wide-margin industrial/military design parameters led to surprisingly long lifetimes, even in harsh conditions, for those that did survive the initial weeding-out.

The B3-09 and B3-14, also called B3-14M, succeeded the B3-04 in early 1976. They used a vacuum luminescent (VL) display and featured reciprocal (both) and square root (B3-14) or percent (B3-09) functions, and debuted the improved "algebraic" logic with separate [=] key. Non-soviet influences are still at work, as evidenced by the similarity of the B3-14 to Corvus models. At about the same time, a Leningrad company, "Svetlana," presented the C3-33, with LED display, change sign, percent, reciprocal and square root, and new, precedent-setting memory functions. Svetlana, a Russian abbreviation for "incandescent light bulb", claim to have designed the first truly all-Soviet ICs in 1976, a version of which went into their C3-33. In response to the C3-33, the Ministry of Electronics soon after put out the B3-26, with VL display and percent, square root, change sign and memory functions.

The next leap in features occurred with the B3-18A, which had much more sophisticated MOS-LSI production techniques similar to the West's that could squeeze 10,000 components on a single chip. This unit had a built-in rechargeable battery and was produced in late 1976 using a VL, 8 digit display. This calculator was remarkable for the many different model numbers it was sold under, all functionally the same but with differing internals. Versions of it have been found labeled B3-18, B3-25A powered by replaceable button-cell batteries, and B3-37 when it switched to an LED 8-digit display and again changed batteries, to standard alkaline AA. These calculators were quite popular and were designed to assist engineers by offering sin/cos/tan functions (including arc), accompanied by a choice of degrees or radians. Other new features included square root, exponential (in x^y format), reciprocal, Pi, log/10^x and ln/e^x. Continuing the trend of being a "sister" calculator to American units, the Rockwell 61R was almost certainly the inspiration for this series.

At about the same time, due to the emergence of Reverse Polish Notation (RPN) as popularized by Hewlett-Packard, a line of RPN calculators was created in collaboration with East Germany, starting with the B3-19(M). This little LED unit (also with a rechargeable battery) was based on full RPN logic (indicated by an [Up Arrow] to indicate stack entry, rather than [=] key) and had an 8 digit mantissa, 2 digit exponent (8+2) display. Its features were similar to the B3-18, but without a 10^x or Pi. A little later, perhaps in early 1977, the Svetlana company came out with another calculator besides the C3-33, called the C3-15. Continuing to develop their pioneer status, the C3-15 came with (besides the by-now standard scientific functions) three memory registers, a ten digit mantissa, 2 digit (10+2) display, a unique magnitude operator (square root of (x^2+y^2)), exponential in the more intuitive y^x form, and astonishingly the calculator is reported to be programmed to consider standard operator precedence. How this was implemented in an RPN calculator is unknown.

Programmable calculators were next, and the first Soviet version was the B3-21, produced in 1977. It boasted 14 storage registers, a maximum program size of 60 key strokes, and quite a few features: square root, square, reciprocal, change sign, x^y, Pi, log/10^x, ln/e^x, and sin/cos (but no tangent). It also had an interesting function, e^ix (which allowed one to determine tangent). This initial foray into programmable calculators was impressive, but had limitations. The B3-34 arrived around 1979 to answer them. The improvements over the B3-21 included 98 program steps, full scientific capability, and indirect addressing for more sophisticated programming. Through a cosmetic change it then became the MK-54, the first of the highly popular MK series of calculators. The B3-34/MK-54 cost 65 rubles, a significant improvement over previous calculators but still the equivalent of two week's salary for the average worker. Its price (as on nearly all of the calculators) was marked into the injection-molded plastic cases, making price changes difficult and demonstrating the Communist regimes famously inflexible pricing philosophy.

The second (and last Soviet-made) generation of calculators, were produced around 1979 and started with the B3-30 and B3-39. The major improvements over the previous generation were their smaller, lighter size, and that they were cheaper and drew less current. The B3-30 featured a return to LCD display technology and claimed to go 800 hours on one set of batteries due to the combination of LCD display and their new CMOS circuitry. Here again, the technology "leap" and visual clues point to a strong assist from the Japanese firm "Sharp". These two calculators had only percent, square root and reciprocal functions. In 1980 the B3-32, with 8+2 VL-display, was designed to help engineers solve two ubiquitous problems; quadratic equations and (small) systems of linear equations. Another calculator made at that time, the B3-36, was similar to the B3-32 in basic scientific features but it provided arc sin/cos/tan and degree/radians conversion. Further, the B3-30 used three AA-size batteries while the B3-36 used a built-in rechargeable type.

Next in the popular MK line of RPNs was the MK-61 in around 1983, featuring 15 storage registers, 105 program steps, unit conversions, nifty things like integer and fractional part, and for the first time logical operations (AND, OR, NOT, and NOP). This calculator cost 85 rubles (as molded into the case). The last hurrah for Soviet-designed programmable RPN calculators was the MK-52 made in Kiev around 1986, with the ability to store 5 programs totaling 512k bytes. It used a VL pixel-based screen and cost 115 rubles, and could accept additional ROM modules containing various programs for another 40 rubles.

Thus ends the USSR's design and manufacture of pocket calculators. By this time (mid- to late 80's) production costs in Asia were vastly less than in Russia, and issues of technological competence were moot, so these third generation calculators (all called MK, but non-RPN) were designed and/or built mostly by such Asian companies as Casio and Sharp. To round out this article I will briefly mention a couple of these calculators, such as the MK-53 from around 1985 which boasted, besides standard calculator functionality, a calendar, clock, stop watch and alarm clock. The MK-60 from around 1986 added no new functions but was able to operate from office- or sunlight via a 5-element solar cell. For engineers, the MK-51 came with statistical functions. The MK-71, a solar-powered version of the MK-51, is still being produced (and imported) in 1996.

Copyright Kenton Green - 2000 - Revised: May 05, 2007.

X-Number World