The term generation is used to distinguish between varying hardware and software technologies. The custom of referring computer era in term of generations came into wide use after 1964. There are five computer generations known till today. Each generations of computer has been discussed in details with their advantages and disadvantages here.
FIRST GENERATION COMPUTER (1942-1955)
In the evolution of computer topic, I have already told you about the early days computers ENIAC, EDVAC and EDSAC which were first generation computers. Full name of ENIAC is Electronic Numerical Integrator And Calculator. EDVAC is known as Electronic Discrete Variable Automatic Computer. And EDSAC is known as Electronic Delay Storage Automatic Calculator. These machines and other of its time were designed using vacuum tubes. A vacuum tube was a fragile glass device that could control and amplify electrical signals. These computers were operated on Machine languages.
ADVANTAGES OF FIRST GENERATION COMPUTERS:
- Vacuum tubes were the only electronic components available during that time.
- Vacuum tube technology made possible to the invention of digital computers.
- They were the fastest calculating machine of their time.
- The computation time of that time computers were in milliseconds.
DISADVANTAGES OF FIRST GENERATION COMPUTERS:
- They were huge in size.
- They were not completely reliable.
- They needed air conditioning because thousands of vacuum tube generated a large amount of heat.
- Hardware failure was occurred frequently.
- They were non-portable.
- Their commercial use was limited because their production was difficult and costly.
- They needed continuous maintenance.
- Manual assembly of individual components was required.
SECOND GENERATION COMPUTER (1955-1964)
The second generation computers were designed using transistors except vacuum tubes. Transistors were invented during 1947. Transistors based computers were not produced on large-scale over a decade. In second generation computers, transistor were the brain of the computers. Transistor was used because they were smaller in size and more reliable than the vacuum tubes. And also they consume less power and generate less heat as compared to vacuum tubes. These computers were operated on assembly languages.
ADVANTAGE OF SECOND GENERATION COMPUTERS:
- They were smaller in size than first generation computers.
- They were more reliable than first generation computers.
- They draw less power and produce less heat than first generation computers.
- These computers can perform computation tasks in microsecond.
- Hardware failure was decreased as compared to first generation computer.
- They could be taken from one place to another. Thus they have portability property.
- Their commercial use was wider than first generation computers.
DISADVANTAGES OF SECOND GENERATION COMPUTERS:
- Second generation computers still needed air conditioning.
- Frequent maintenance was also required as in the first generation computers.
- Manual assembly of individual component into functioning was still required.
- Its commercial production was difficult and costly.
THIRD GENERATION COMPUTER (1964-1975)
Third generation computers were designed using IC’s (Integrated Circuits). Micro electronic devices were invented with advancement in technology. With the help of microelectronic technology, it made possible to integrate a large number of circuit components into a single piece of silicon. This Silicon was known as chips. And this technology is called Integrated circuit or IC. This small chip contained several transistors in it. Third generation computers are operated on structured programming languages. Structured programming languages are C, FORTRAN and Pascal.
ADVANTAGES OF THIRD GENERATION COMPUTERS:
- With the invention of IC’s third generation computers were smaller than previous generations.
- Third generation computers were more reliable than previous generations.
- They generate less heat and consume less power than previous generations.
- The computation time was reduced from microsecond to nanosecond.
- Maintenance cost was low because hardware failure rarely occurred as compared to previous generations.
- They were portable.
- They were used widely in various commercial applications all over the world.
- Manual assembly of individual components was not required.
- Commercial production was easier and cheaper than previous generations
DISADVANTAGES OF THIRD GENERATION COMPUTERS:
- Air conditioning required in many cases.
- Highly sophisticated technology required for the manufacturing of IC chips.
FOURTH GENERATION COMPUTER (1975-1990)
Initially, an IC could have only about 10 to 20 components in it and this technology is known as Small-Scale Integration (SSI). Later, with the advancement of technology, it became possible to integrate more than 100 components in a single chip and this technology is known as Medium Scale Integration (MSI). Then came the era of LSI (Large-Scale Integration) and VLSI (Very large-scale integration). These technologies could integrate more than 30000 component into a single chip. The fourth generation computers used LSI chips. VLSI technology had million of components inside a single chip. LSI and VLSI technology had led to the development of very small and extremely powerful computer.
ADVANTAGE OF FOURTH GENERATION COMPUTERS:
- They are the Smallest in size because of their high component density.
- They are more reliable than the previous generations.
- They do not need air conditioning in most cases.
- They are much faster in computation than previous generations.
- Hardware failure is negligible hence minimum maintenance is required.
- Easy portable because of its size.
- They can be used in totally in general purpose.
- Commercial production was cheaper.
DISADVANTAGES OF FOURTH GENERATION COMPUTERS:
- Highly sophisticated and costly technology was required to manufacture the LSI and VLSI chips.
FIFTH GENERATION COMPUTERS (1990-ON WARDS)
The earlier VLSI technology has further advanced to ULSI (Ultra Large Scale Integration) technology in the fifth generation computers. This has resulted in the production of micro chips having 10 million electrical components. The fifth generation computer has brought more powerful super computers based on parallel processing technology. During fifth generation computer, there was tremendous growth of the computer network. In the area of operating system the fifth generation included multithreading and distributed operating systems. In the area of programming languages some of the concepts gained popularity during fifth generation like JAVA language, parallel programming languages etc.
ADVANTAGES OF FIFTH GENERATION COMPUTERS:
- Fifth generation computers are smaller than the previous generations.
- They are portable and handy.
- They are more powerful than fourth generation computers.
- Concept of parallel processing is introduced.
- Capabilities for solving complex problems.
- Fifth generation computers are general purpose computers.