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Elektronika B3-21
{{unreferenced, date=November 2015 Elektronika B3-21 (Cyrillic: Электроника Б3-21) was the first Soviet programmable calculator. It was released in 1977 and was sold initially for 350 rubles (190 in 1980–1981, and just 80 rubles at late 1981). 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 (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 (7 if the value includes decimal dot), 2 exponent digits * Operations - besides 4 arithmetic ones there were 1/x, x2, xy, 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 xy taking the longest time of about 3 seconds) * Display - red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Calculator
Programmable calculators are calculators that can automatically carry out a sequence of operations under the control of a stored computer programming, program. Most are Turing complete, and, as such, are theoretically general-purpose computers. However, their user interfaces and programming environments are specifically tailored to make performing small-scale numerical computations convenient, rather than for general-purpose use. The first programmable calculators such as the IBM CPC used punched cards or other media for program storage. Hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, flash memory, or in battery-backed read/write memory. Since the early 1990s, most of these flexible handheld units belong to the class of graphing calculators. Before the mass-manufacture of inexpensive dot-matrix LCDs, however, programmable calculators usually featured a one-line numeric or alphanumeric display. The Big Four manufacturer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruble
The ruble or rouble (; rus, рубль, p=rublʲ) is a currency unit. Currently, currencies named ''ruble'' in circulation include the Russian ruble (RUB, ₽) in Russia and the Belarusian ruble (BYN, Rbl) in Belarus. These currencies are subdivided into one hundred kopeks. No kopek is currently formally subdivided, although '' denga'' (½ kopek) and ''polushka'' (½ denga, thus ¼ kopek) were minted until the 19th century. Additionally, the Transnistrian ruble is used in Transnistria, an unrecognized breakaway province of Moldova. Historically, the grivna, ruble and denga were used in Russia as measurements of weight. In 1704, as a result of monetary reforms by Peter the Great, the imperial ruble of the Russian Empire became the first decimal currency. The silver ruble was used until 1897 and the gold ruble was used until 1917. The Soviet ruble officially replaced the imperial ruble in 1922 and continued to be used until 1993, when it was formally replaced with the Russi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elektronika B3-34
Elektronika B3-34 (Cyrillic: Электроника Б3-34) was a Soviet programmable calculator. It was released in 1980 and was sold for 85 rubles. B3-34 used reverse Polish notation and had 98 bytes of instruction memory, four stack user registers and 14 addressable registers. Each register could store up to 8 mantissa or significand digits and two exponent digits in the range to . The first Soviet programmable stationary calculator the ISKRA 123, using mains power, was released at the beginning of the 1970s. The first programmable battery-powered pocket calculator Elektronika B3-21 was developed by the end of 1977 and released at the beginning of 1978. Its successor, B3-34, wasn't backward compatible with B3-21. The instruction set, hardware architecture and microcode of the B3-34 defined the standard of the later Soviet programmable hand-held and office-desk calculators: MK-61, MK-52, MK-54, MK-56. Model numbers do not follow any special order: MK-54 is a slightly upgr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Significand
The significand (also coefficient, sometimes argument, or more ambiguously mantissa, fraction, or characteristic) is the first (left) part of a number in scientific notation or related concepts in floating-point representation, consisting of its significant digits. For negative numbers, it does not include the initial minus sign. Depending on the interpretation of the exponent, the significand may represent an integer or a fractional number, which may cause the term "mantissa" to be misleading, since the ''mantissa'' of a logarithm is always its fractional part. Although the other names mentioned are common, ''significand'' is the word used by IEEE 754, an important technical standard for floating-point arithmetic. In mathematics, the term "argument" may also be ambiguous, since "the argument of a number" sometimes refers to the length of a circular arc from 1 to a number on the unit circle in the complex plane. Example The number 123.45 can be represented as a decimal floati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-emitting Diode
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seven-segment Display
A seven-segment display is a display device for Arabic numerals, less complex than a device that can show more characters such as dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information. History Seven-segment representation of figures can be found in patents as early as 1903 (in ), when Carl Kinsley invented a method of telegraphically transmitting letters and numbers and having them printed on tape in a segmented format. In 1908, F. W. Wood invented an 8-segment display, which displayed the number 4 using a diagonal bar (). In 1910, a seven-segment display illuminated by incandescent bulbs was used on a power-plant boiler room signal panel. They were also used to show the dialed telephone number to operators during the transition from manual to automatic telephone dialing. They did not achieve widespread use until the advent of light-emitting diode, LEDs in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
