Elka 6521
Elka 6521 is the first Bulgarian electronic calculator . The name Elka stands for EL ectronic KA lculator, the digits 65 stand for the year of development, 2 for the number of devices produced in the pilot series and ultimately the 1 for the fact that, from the developer's point of view, it was the first real computer.
It was presented in 1965 at the Russian “Inforga” trade fair. It weighs 8.5 kg, has three registers and works with twelve decimal places . Additions take 0.3 seconds and divisions take 0.5 seconds. The power consumption is 35 watts . Nixie tubes are used to display the results and he was able, connected to a typewriter, to output the results to them. Desk calculators from the "Elka" series were very common in Bulgaria and the Soviet Union until 1980. They were produced in the “ Electronics ” factory in Sofia .
The "Elka" calculator was developed in 1965 by the Mathematics Institute at the Bulgarian Academy of Sciences . Mainly responsible were Stefan Angelov and Ljubomir Antonov Petar Popov , who were honored with the Dimitroff Prize in 1966 .
The computer has germanium - transistors , 16-bit registers and had a number of advantages over the existing technology: He dominated the extraction of square root , integer division, the calculation of the average value and the exponentiation . He was also able to handle negative numbers. The Elka was well received in the market and was manufactured from 1966 by the Zentralinstitut für Computertechnik , which developed a number of calculating machines. Further developments were "Elka 22" (1967) with a digital indicator lamp and "Elka 25" with a printer. The production of Elka 22 and 25 began in 1967 in the “Office Equipment” factory in Silistra .
In 1969, the Research Institute for Electronic Calculator (NIPCIEK) was founded with the director Ljubomir Antonov that that the successor models of Elka 6521 and the first calculator with integrated circuits "Elka 42" developed in 1970 with great success at the World Exhibition Expo '70 in Osaka shown were the only computer with integrated circuits for the time being. The integrated circuits used are of the ISA type, namely the UIMOST series, which was developed at the Institute for Microelectronics and contains a standard set of counters, triggers and logic elements.
In 1971 the first electronic cash register "Elka 77", still with discrete components, and the first electronic computer for "Scientific Computing", "Elka 99", were developed. Following this, series 40 electronic computers with displays and printers with built-in Bulgarian MOS ICs (1972) were built, and in 1974 a series of 50 were built containing around 100 elements per chip. At the request of a Swiss company, “Elka 101” was the first Bulgarian electronic pocket calculator to be developed, of which 50,000 were delivered to Switzerland.
Individual evidence
- ↑ Sandacite.bg Bulgarian
- ^ Bulgarian Science Association Bulgarian
- ↑ Electronics in the economic policy of Bulgaria in the 1960s to 1980s. Century
- ↑ 40 years of the Central Institute for Computer Technology (PDF) in Bulgarian