Chapter 2 :- History and Evolution of Computers Summary The earliest known device for calculation is Abacus. In 1642, Blaise Pascal developed the first basic calculator In 1690 Leibnitz developed a machine that could perform addition, subtraction, multiplication, division and calculate square roots. Charles Babbage in 1822 designed and built a model called difference engine. Generations of Computers 1. First Generation Computers (1945-55) :- The first generation of computers started with ENIAC. It was then followed by the IBM UNIVAC I. The first generation computers used vacuum tubes. Because of vacuum tubes, the first generation computers were very large, required lot of energy, slow in input/output, and suffered with heat and maintenance problems. 2. Second Generation Computers (1955-65) :- Transistors were used in the second generation computers. Transistor is a small component made of semiconductor material.The computers now could perform operations comparatively faster. An
All computer course for class 9th to 12th with proper practical and theory .........