The document discusses the history and generations of computers. It describes the five generations from the 1940s to present. The first generation used vacuum tubes in computers like ENIAC which was large, slow, and produced a lot of heat. The second generation replaced tubes with transistors, improving speed and reducing size and heat. The third generation used integrated circuits which further reduced size and increased speed. The fourth generation included large scale integrated circuits, and the fifth generation uses very large scale integrated circuits, making computers small, inexpensive and high performing.

1. 19GN3101
Computer Skills
Session -2
1

2. CHAPTER 1: Introduction To Computers
Why Computers?
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3. CHAPTER 1: Introduction To Computers
🢂Zero th generation (1642 to 1945)
🢂First Generation (1945 to 1955)
🢂Second generation (1955 to 1965)
🢂Third generation (1966 to 1970)
🢂Fourth generation (1971 to 1980)
🢂Fifth generation (1980 to present)
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4. CHAPTER 1: Introduction To Computers
🢂Mechanical calculators was developed as
computing device.
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5. CHAPTER 1: Introduction To Computers
🢂In 1946 first electronic computer ENAIC (Electronic
Numerical Integrator and Calculator ) was developed by
Mr. J.Presper Eckert and Mr. John Manuchly at
University of Pennsylvania.
🢂It uses 18,000 vacuum tubes and its cast was $500,000.
🢂Its weight was 30 tons and occupied a 30 by 50 foot
space.
🢂It produced large amount of heat.
🢂Its speed was very slow.
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6. CHAPTER 1: Introduction To Computers
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7. CHAPTER 1: Introduction To Computers
🢂In this second generation vacuum tubes was
replaced by transistors.
🢂Speed / performance of this generation computers
was improved in comparison to first generation
computers.
🢂Size, price , and heat produced reduced by using
transistors.
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8. CHAPTER 1: Introduction To Computers
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9. CHAPTER 1: Introduction To Computers
🢂 In this third generation transistors was replaced by IC’s (Integrated
Circuits i.e fabrication of thousands electronic components on single silicon
chip ).
🢂Using this drastic reduction in the size of computers.
🢂Speed / performance was high in comparison to third generation.
🢂Heat produced by computers was reduced.
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10. CHAPTER 1: Introduction To Computers
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11. TOPIC
CHAPTER 1: Introduction To Computers
🢂In this generation IC’s are replaced by LSI (Large Scale Integrated
Circuits : more number of electronic components on silicon chip)
🢂These are low cast, small size and high performance in comparisons
to third generation computers
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12. TOPIC
CHAPTER 1: Introduction To Computers
🢂In this generation LSI are replaced by VLSI (Very
Large Scale Integrated Circuits)
🢂Size and cost of these computers is very less and
performance is very high
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