1. History of computer science
Milennial process of creation and development of computer marked by various researchers and scientists
BLAISE PASCAL
GOTTFRIED WILHEM VON LEIBNIZ
CHARLES BABBAGE
ADA BYRON
HERMAN HOLLERITH
HOWARD H. AIKEN
JOHN VON NEUMANN

2. There are 4 main phases in the development of computers:
saving results
process of calculating
separation of entering data to calculating
universal using computers with programs

3. abacus
Abacus(also called a counting frame) is the earliest known tool for calculating. The use of the word abacus dates before 1387 AD, many centuries before the adoption of the written Hindu-Arabic numeral system. Nowadays, it is famous for its usage in elementary schools. It is forerunner of computers, but it is not computer.
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4. BLAISE PASCAL
Pascal was well-known mathematician, scientist and theologian. When he was only 19 (in 1642)  he started some pioneering work on calculating machines. After three years of effort and fifty prototypes, he built 20 finished machines called ’’Pascal’s calculator’’. In fact his father was local judge, so Pascal wanted to help him. The machine was based on gear mechanism.

5. GOTTFRIED WILHEM VON LEIBNIZ
Leibniz was born in In 1671, he invented digital mechanical calculator, called step reckoner and it was completed in It was the first calculator that could perform all four arithmetic operations. That mechanism, that Leibniz has invented, is used even nowadays.

6. CHARLES BABBAGE
In 1822, Babbage invented difference engine. In 1837 Charles Babbage first described his Analytical Engine which is accepted as the first design for a modern computer, and because of that he is considered by some to be a “father of the computer’’. The analytical engine had expandable memory, an arithmetic unit, and logic processing capabilities able to interpret a programming language with loops and conditional branching. Although never built, the design has been studied extensively and is understood to be Turing equivalent. 

7. ADA BYRON
Ada Byron was the daughter of poet Lord Byron. She was mathematician, she funded the project of Analytical engine because she predicted that it could be used for painting and even composing music. She wrote the method for calculating a sequence of Bernoulli numbers with the Engine witch is consider as first computer program, and Ada Byron as first programmer.

8. HERMAN HOLLERITH
In 1880, Herman Hollerith was an American inventor who developed an electromechanical punched card tabulator to assist in summarizing information and, later, accounting. He was statistician, and he noticed that in census, the most frequent answers are “Yes” or “No”. So, he came up with idea to punch the card on certain places when the answer is “Yes” and not to punch when the answer is negative. It is forerunner of Binary numbers “0” and “1”. Those card were used up until 1970.

9. THE PRICIPLE OF PUNCHED CARDS

10. HOWARD H. AIKEN
Howard Aiken in 1944 together with company called IBM constructed computer machine that had input and output device, memory, arithmetic and control authority. It was a huge machine, 17m long and 2.5m wide. Once it stopped working, it turned out to be due to a moth that is burst into the relay. Since then, then, the bugs are called Bug.

11. ENIAC (Electronic Numerical Intergrator And Computer)
The first general-purpose electronic computer was created during World Wor 2 after the project ЕNIAC (Eletronic Numerical Integrator AND Computer). For input and output data it was used a punched cards and it was 1000 times faster than previus computer. It was huge in size (10 х 20м) and weighed 30 tons (hardware – of hardware). It was used for military purposes, but also for weather forecast.

12. JOHN VON NEUMANN
John von Neumann with his colleagues invented the computer called ЕDVAC. It was much lighter than previus models with 100 times more memory. Applications were first time stored in memory. In this way both the programs and input data were very easily changed. This is the principle of work and todays computers. The computer first receives magnetic disks. More about Neumann can be found at :

13. Graphical presentation of the growth of sales of desktop and laptop computers, and smart phones in Europe can be seen in the table below:
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