1979 -
Electronika B3-09M
The scale on the monitor: 1:1
Electronica B3-09M was the next model of a pocket microcalculator following in the footsteps of B3-04. Стоимость калькулятора была снижена до 90 руб. (Б3-04 стоил 220 руб.), а через три года — до 55 руб. Mass production commenced in 1976. В микрокалькуляторе используется естественная форма представления запятой: уже не нужно заранее выставлять место запятой и задавать точность вычисления как в ранних моделях настольных калькуляторов. During the calculation, a point on the display separating the integral part of the number moves back and forth automatically. The calculator features an eight-digit vacuum fluorescent display.
B3-09M has four microcircuits, including the 23-digit shift register K145AP1, the display control K145PP1, the operating register K145IP2 and the in-house microprocessor K145IP1. The first pocket microcalculator B3-04 (as well as B3-14 and B3-14M) featured the above microcircuits too, being the same calculators marketed in different shapes. The only difference between the said calculators consisted in the choice of functions: B3-14 added on the functions of square rooting and percentage calculation, whereas B3-14M could not perform operations with percents.
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B3-09M performs the four regular arithmetic operations, memory-related processes, changes of sign, semi-automatic exponentiation (whole positive exponents only) and operations with constants. Before proceeding to work, the user has to press the “C” key to clear registers.

For power supply the calculator can use both a line adapter and four AA batteries. Size — 158✕86✕36 mm. Total weight — 400 g.

Sources: http://www.enlight.ru/post/6067, http://statehistory.ru/1290/Pervye-sovetskie-mikrokalkulyatory/, http://www.leningrad.su/museum/show_calc.php?n=30.