World day of the programmer of ENIAC 2/14/1946

ENIAK (ENIAC, abbr. from Electronical Numerical Integrator and Calculator — Electronic numerical integrator and the calculator) — the first large-scale electronic digital computer which could be reprogrammed for the solution of complete range of tasks. It is constructed in 1946 by request of U.S. Army in Laboratory of ballistic researches for calculations of tables of firing. It is started on February 14, 1946.

The computer architecture was developed in 1943 by John Presper Eckert and John William Mokli, scientists from the University of Pennsylvania. Unlike the Z3 complex created in 1941 by the German engineer Conrad Tsuze using mechanical relays in ENIAKE as a basis of component base vacuum lamps were used. In total the complex included 17468 lamps, 7200 silicon diodes, 1500 relays, 70000 resistors and 10000 condensers. Power consumption — 150 kW. Computing power — 300 transactions of multiplication or 5000 addition operations per second. Weight — 27 tons. Calculations were made in a decimal system.

Till 1948 for reprogramming of ENIAC it was necessary to perekommutirovat it again while Z3 was able to read out programs from the chad tape.

The first successful numerical weather forecast was made in 1950 by a team of the American meteorologists — Jules Charney, Filip Thomson, Larry Gates, Norwegian Ragnar Fyyurtoft and the mathematician John von Neumann using ENIAC. They used reduced models of atmospheric flows on the basis of the barotropic equation of a whirlwind of speed. This simplification lowered computing complexity of a task and allowed to make calculations using computing powers available at that time. [1]