Generation of Computer (Phase of development )

Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. 

First Generation (1940-1956) Vacuum Tubes

  • The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. 
  • They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.
  • First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. 
  • Input was based on punched cards and paper tape, and output was displayed on printouts.
  • Examples -The UNIVAC and ENIAC.
  • The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.

The main features of first generation are:
  1. Vacuum tube technology.
  2. Unreliable.
  3. Supported machine language only.
  4. Very costly.
  5. Generated lot of heat.
  6. Slow input and output devices.
  7. Huge size.
  8. Need of A.C.
  9. Non-portable.
  10. Consumed lot of electricity.

Second Generation (1956-1963) Transistors

  • Transistors replaced vacuum tubes and ushered in the second generation of computers. 
  • The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. 
  • The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. 
  • Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. 
  • Second-generation computers still relied on punched cards for input and printouts for output.
  • Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. 
  • High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN.
  • These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.
  • The first computers of this generation were developed for the atomic energy industry.
  • EXAMPLE- IBM 1620 , CDC 1604

The main features of second generation are:
  1. Use of transistors.
  2. Reliable in comparison to first generation computers.
  3. Smaller size as compared to first generation computers.
  4. Generated less heat as compared to first generation computers.
  5. Consumed less electricity as compared to first generation computers.
  6. Faster than first generation computers.
  7. Still very costly.
  8. A.C. needed.
  9. Supported machine and assembly languages.


Third Generation (1964-1971) Integrated Circuits

  • The development of the integrated circuit was the hallmark of the third generation of computers. 
  • Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
  • Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. 
  • Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.
  • Example -IBM-360 series ,  Honeywell-6000 series , PDP(Personal Data Processor).

The main features of third generation are:
  • IC used
  • More reliable in comparison to previous two generations
  • Smaller size
  • Generated less heat
  • Faster
  • Lesser maintenance
  • Still costly
  • A.C needed
  • Consumed lesser electricity
  • Supported high-level language


Fourth Generation (1971-Present) Microprocessors

  • The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. 
  • The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.
  • In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. 
  • Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.
  • As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. 
  • Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.
  • Example-  DEC 10 , STAR 1000 , PDP 11 , CRAY-1(Super Computer).

The main features of fourth generation are:
  1. VLSI technology used
  2. Very cheap
  3. Portable and reliable
  4. Use of PC's
  5. Very small size
  6. Pipeline processing
  7. No A.C. needed
  8. Concept of internet was introduced
  9. Great developments in the fields of networks
  10. Computers became easily available.

Fifth Generation (Present and Beyond) Artificial Intelligence

  • Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today.
  • The use of parallel processing and superconductors is helping to make artificial intelligence a reality. 
  • Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. 
  • The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.


The main features of fifth generation are:
  1. ULSI technology.
  2. Development of true artificial intelligence.
  3. Development of Natural language processing.
  4. Advancement in Parallel Processing.
  5. Advancement in Superconductor technology.
  6. More user friendly interfaces with multimedia features.
  7. Availability of very powerful and compact computers at cheaper rates.

Some computer types of this generation are:
  1. Desktop
  2. Laptop
  3. NoteBook
  4. UltraBook
  5. ChromeBook