The development of computers has followed different has followed different steps in the technology used and these steps of technological differences are called as Generations, in computer technology. The custom of referring computer eras as generation has been widely practiced only after 1960. There are totally five generations’ computers till today.
1. First Generation Computers (1950s): The first generation of computers was those computers which used vacuum tubes (valves) technology. Almost all the early computers like ENIAC, EDVAC, EDSAC etc, were made a reality only by the invention of “vacuum Tube”, which is a fragile glass device that can control and amplify electronic signals. This machine language was the language of these computers. The major advantage of the vacuum tube technology is that it made the advent of electronic digital computers. Vacuum tubes were only electronic devices available during those which made computing possible.
Limitations of First Generations Computers: Since, this was the beginning of the era of computers, it went through lot of limited factors, nevertheless, and it paved the way for the modern computer era. The limitations of this very first generation of computers are as follows:
a) Their operating speed was slow and they had restricted computing capacity.
b) They consumed high power generated great amount of heat.
c) They were bulky and required large space.
d) They had a short span of life.
e) The programming capabilities were limited.
f) They were not very reliable.
g) Frequent breakdowns were common.
h) They had small primitive memories and so auxiliary storage.
Later, these first generation computers were improved and they adopted a new technology for the main memory called magnetic core. UNIVAC and Leo are the computers belonging to first generation of computers.
Second Generation Computers (1960’s): With the development of transistors and their use in circuits, magnetic core for memory storage, the vacuum tubes of first generation are replaced by transistors to arrive at second generation of computers. The size of transistors was much smaller when compared to vacuum tubes; they consumed less power, and generated less heat and were faster and reliable. The major advantage of use of transistors was that cost of computer has come down as well as power consumption. Even the cost of computer reduced drastically, they were more reliable than first generation of computers. Thus, a new technology use in the first generations of computers, upgraded them to next, i.e., Second Generations of Computers.
Third Generations of Computers (1980’s): With the development of silicon chips, the third generations of computers came into existence. These computers used compact integrated circuit (ICs) of silicon chips in place of transistors. Each of these integrated circuit ICs coming into picture the size of computers, its cost, heat generation and power consumption’s decreased to a great extent, speed and reliability, increased as compared to previous generations. These machines used ICs with large scale integration (LSI). This was the revolution in the computer technology, which paved way for the faster growth of the next generations of computers.
Fourth Generations of Computers (1980s): The computers belongings to this generations used integrated circuit with very large scale integration (VLSI). These computers had high processing powers, low maintenance, high reliability and very low power consumption’s These computers have reduced the cost as well as the size has come down drastically this generation of computers has eliminated almost all the limitations of the earlier generations of computers. Most of today’s computers being properly used belong to this generation.
Fifth Generation Computers (1990s): These computers use optic fiber technology to handle artificial intelligence, Expert systems, Robotics etc. These computers have very high processing speeds and are more reliable. These are more sophisticated computers, which are used in higher applications and are usually more suitable for higher end application, rather than the day to day computing. They are mostly used for scientific purposed as well as for research.
The Computer Generations and their Limitations in Online Computer Studies in USA