Elektronika B3-21 (Cyrillic: Электроника Б3-21) was the first Soviet
programmable calculator
Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program. Most are Turing complete, and, as such, are theoretically general-purpose computers. However, their user inter ...
. It was released in 1977 and was sold initially for 350
ruble
The ruble (American English) or rouble (Commonwealth English) (; rus, рубль, p=rublʲ) is the currency unit of Belarus and Russia. Historically, it was the currency of the Russian Empire and of the Soviet Union.
, currencies named ''rub ...
s (190 in 1980-81, and just 80 rubles at late 1981). For comparison, 120 rubles was a monthly engineer's salary.{{citation needed, date=November 2015 Production was stopped in 1982 because of introduction of more advanced
Elektronika B3-34.
Features
* program memory - 60 steps in RAM (no ROM, the code is lost after shut down);
* data memory - 2 operating registers, 7 additional directly addressed registers, 6 loop stack registers;
* accuracy - 8 digits in the
Significand
The significand (also mantissa or coefficient, sometimes also argument, or ambiguously fraction or characteristic) is part of a number in scientific notation or in floating-point representation, consisting of its significant digits. Depending on ...
(7 if the value includes decimal dot), 2 exponent digits;
* operations - besides 4 arithmetic ones there were 1/x, x
2, x
y, sqrt(x), exp(x), ln(x), sin(x), cos(x);
* conditional and unconditional branching, subroutine calls;
* speed - 3-5 operations (program steps) per second on average (with x
y taking the longest time of about 3 seconds);
* display - red
LED seven-segment display
A seven-segment display is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot matrix displays.
Seven-segment displays are widely used in digital clocks, electronic meters, bas ...
, with small lenses in front of each digit (to enlarge the very small LED digits used)
* powered by disc accumulators (4 * 1.25 Volts) or charger.
Derived models
* Elektronika MK-46 - desktop version, differed in having 66 steps of program memory, digital inputs for connecting external devices, and output, e.g. for printer (along with functionality to control them);
* Elektronika MK-64 (and later Elektronika MS-1103) - the same as MK-46 but with internal analog-to-digital conversion (ADC) installed so that several analog inputs could be measured (measurements from -9.99 to 9.99 Volts with accuracy of 0.02 Volts);
* Elektronika MK-47 - rare handheld clone of B3-21, allowing the storage of programs on magnetic memory cards.
External links
- Detailed description of B3-21 at the online calculator collection site by Viktor T. Toth
Elektronika programmable calculators