1. ENIAC — Electronic Numerical Integrator And Computer

2. With ENIAC starts the first generation of computers which lasted until 1959. One big weakness of this generation was the heating of the electronic lamps which needed additional cooling devices. The speed of those computers was about 20 000 operations in one second, had limited memory and for remembering the data a perforated paper card was used. ЕNIAC used 4 accumulators like these controlled with a special unit of the Multiplier,and could perform385 operations of multiplications in a second. With 5 accumulators it was peculiarly controlled with the unit of divider / calculator of square cubes and could perform 40 operations of division and 3 of calculating a square cube in a second.

3. From physical aspect ENIAC was huge compared to the contemporary computers. It had 17.468 vacuum pipes inside, 7.200 crystal diodes, 1.500 relays, 70.000 resistors, 10.000 condensers and about 5 million soldered spoilers by hand. It weighed about 27 tones with dimensions of 2,4м x 0,9м x 30м., and spent 150 кW electricity. ENIAC was a huge machine which was on 150 square meters surface and weighed 30 tones. ENIAC can perform 5000 additions, 257 multiplications and 38 divisions on numbers in one second.

4. For a long time ENIAC was considered for the first electronic computer. It was an idea of John William Mauchly and Presper Eckert from the University of Pennsylvania in 1946. ЕNIAC is shortened from Electronic Numerical Integrator And Computer, and is the first electronic computer that could be programmed for solving numerous calculating problems, although the previous computers had similar characteristics.

5. A few examples of ENIAC are exposed in the School for engineering and applied sciences at the University in Pennsylvania. This school has 4 from 40 original plans of ENIAC. The artifacts of the photos are about 1/10 of its real size.

6. Since 2004 the silicon chip with the dimension of 0,5 mm by side has the same capacity as ENIAC which occupied a whole room. ЕNIAC was a simple design that was never repeated. With its look and function from 1943 it was known that the computer will have many problems that are not solved, but it was an inspiration and had a great influence for the development of the classic computers.

7. Since 1948 a great improvement is made including the primitive “only-read” mechanism for programming which used the function table as the program R.O.M. The three numbers from one accumulator were used as counter of programs, the other accumulator was used as main, and the other for reading the addresses for reading data from the function table, while the rest of the accumulator (1-5,7-9,9- 14,17-19) was mainly used as a memory for data.

8. ЕNIAC – worked until October 1955. ENIAC is designed and used in order to calculate the balistic tables for the American army. The first problems solved on ENIAC were connected with the construction of the hydrogen bomb. The constructors John Mauchly and Presper Eckert built-in 18000 electronic lamps.

9. We have downloaded the text from www.wikipedia.org,and the pictures from www.google.com We have downloaded the text from www.wikipedia.org,and the pictures from www.google.com www.wikipedia.org www.google.com www.wikipedia.org www.google.com

10. Collaborative group : 4

11. Worked by : Elena Ajtova and Vojdan Karakatrajkov