Elektronika B3-21
Elektronika B3-21 was the first Soviet programmable calculator. It was released in 1977 and was sold initially for 350 rubles. For comparison, 120 rubles was a monthly engineer's salary. Production was stopped in 1982 because of introduction of more advanced Elektronika B3-34.
Features
- Program memory - 60 steps in RAM
- Data memory - 2 operating registers, 7 additional directly addressed registers, 6 loop stack registers
- Accuracy - 8 digits in the Significand, 2 exponent digits
- Operations - besides 4 arithmetic ones there were 1/x, x2, xy, sqrt, exp, ln, sin, cos
- Conditional and unconditional branching, subroutine calls
- Speed - 3-5 operations per second on average
- Display - red LED seven-segment display, with small lenses in front of each digit
- Powered by disc accumulators 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.
- Elektronika MK-64 - the same as MK-46 but with internal analog-to-digital conversion installed so that several analog inputs could be measured.
- Elektronika MK-47 - rare handheld clone of B3-21, allowing the storage of programs on magnetic memory cards.