Generations of Computers

The development of electronic computers can be divided into five generations depending upon the technologies used. They include:

First Generation of Computers (1942-1955)

The beginning of the commercial computer age is from UNIVAC (Universal Automatic Computer). It was developed by two scientists Mauchly and Echert at the Census Department of the United States in 1947. The first generation computers were used during 1942-1955. They were based on vacuum tubes Examples of first-generation computers are ENIVAC and UNIVAC-1.
Advantages
1. Vacuum tubes were the only electronic component available during those days.
2. Vacuum tube technology made it possible to make electronic digital computers.
3. These computers could calculate data in a millisecond.
Disadvantages
1. The computers were very large.
2. They consumed a large amount of energy.
3. They heated very soon due to thousands of vacuum tubes.
4. They were not very reliable.
5. Air conditioning was required.
6. Constant maintenance was required.
7. Non-portable.
8. Costly commercial production.
9. Limited commercial use.
10. Very slow speed.
11. Limited programming capabilities.
12. Used machine language only.
13. Used magnetic drums which provide very fewer data storage.
14. Used punch cards for input.
15. Not versatile and is very faulty.

Second Generation Computers (1955-1964)

The second-generation computers used transistors. The scientists at Bell Laboratories developed the transistor in 1947. These scientists include John Barden, William Brattain and William Shockley. The size of the computers was decreased by replacing vacuum tubes with transistors. Examples of second-generation computers are IBM 7094 series, IBM 1400 series and CDC 164 etc.
Advantages
1. Smaller in size as compared to first-generation computers.
2. The 2nd generation Computers were more reliable
3. Used less energy and were not heated.
4. Wider commercial use
5. Better portability as compared to first-generation computers.
6. Better speed and could calculate data in microseconds
7. Used faster peripherals like tape drives, magnetic disks, printers etc.
8. Used Assembly language instead of Machine language.
9. Accuracy improved.
Disadvantages
1. A cooling system was required
2. Constant maintenance was required
3. Commercial production was difficult
4. Only used for specific purposes
5. Costly and not versatile
6. Punch cards were used for input.

Third Generation Computers (1964-1975)

The Third generation computers used the Integrated Circuit (IC). Jack Kilby developed the concept of the integrated circuit in 1958. It was an important invention in the computer field. The first IC was invented and used in 1961. A single IC chip may contain thousands of transistors. The computer became smaller in size, faster, more reliable and less expensive. Examples of third-generation computers are IBM 370, IBM System/360, UNIVAC 1108 and UNIVAC AC 9000 etc.
Advantages
1. Smaller in size as compared to previous generations.
2. More reliable.
3. Used less energy
4. Produced less heat as compared to the previous two generations of computers.
5. Better speed and could calculate data in nanoseconds.
6. Used fan for heat discharge to prevent damage.
7. Maintenance cost was low because hardware failure is rare.
8. General purpose
9. Could be used for high-level languages.
10. Good storage
11. Versatile to an extent
12. Less expensive
13. Better accuracy
14. Commercial production increased.
15. Used mouse and keyboard for input.
Disadvantages
1. Air conditioning was required.
2. Highly sophisticated technology is required for the manufacturing of IC chips.

Fourth Generation Computers (1975-Present)

The fourth generation computers started with the invention of the Microprocessor. The Microprocessor contains thousands of ICs. Ted Hoff produced the first microprocessor in 1971 for Intel. It was known as Intel 4004. The technology of integrated circuits improved rapidly. The LSI (Large Scale Integration) circuit and VLSI (Very Large Scale Integration) circuit was designed. It greatly reduced the size of the computer. The size of modern Microprocessors is usually one square inch. It can contain millions of electronic circuits. Examples of fourth-generation computers are Apple Macintosh & IBM PC.
Advantages
1. More powerful and reliable than previous generations.
2. Small in size
3. Fast processing power with less power consumption
4. Fan for heat discharging and thus to keep cold.
5. No air conditioning is required.
6. General purpose
7. Commercial production
8. Less need for repair.
9. Cheapest among all generations
10. All types of High-level languages can be used in this type of computers
Disadvantages
1. The latest technology is required for the manufacturing of Microprocessors.

Fifth Generation Computers (Present & Beyond)

Scientists are working hard on the 5th generation computers with quite a few breakthroughs. It is based on the technique of Artificial Intelligence (AI) or Biochip. With A.I computers can understand spoken words, imitate human reasoning and respond to their surroundings using different types of sensors. Scientists are constantly working to increase the processing power of computers. They are trying to create a computer with real IQ with the help of advanced programming and technologies. IBM Watson computer is one example that outsmarts Harvard University Students. The advancement in modern technologies will revolutionize the computer in future.
Advantages
1. They are very portable
2. They are much faster than the previous ones.
3. Easy to repair
4. They function with natural language
Disadvantages
1. It could lead to unemployment due to AI replacing jobs.
2. They can be used for spying on people.
3. Creating AI with human-like intelligence is a difficult and time-consuming task.
4. It is a potential tool for scammers to scam people through the internet