Generations of computer from 1st to 5th. YASH PAL, March 11, 2022March 10, 2026 Generations of computers [1st to 5th] – A computer may be defined as a device that can store, process, and retrieve data as and when required. A generation of computers is called the step-by-step growth in the hardwares of the computer. Generation in computers is a technological change; a computer was being used. Initially, the generation term was used to distinguish between varying hardware technologies. Nowadays, a generation includes both hardware and software, which together make up an entire computer system. There are five computer generations known to date. Each generation has been discussed in detail along with its time period and characteristics. First-generation (1946-1959) Second generation (1959-1965) Third generation (1965-1971) Fourth generation (1971-1980) Fifth-generation (1980 to till date) First-generation Computers The period of the first generation was from 1946 to 1959. These computers used vacuum tubes as the basic components for memory and circuitry for the CPU. These tubes, like electric bulbs, produced a lot of heat, and the installations used to fuse frequently. Therefore, they were very expensive, and only larger organizations were able to afford them. In this generation, mainly batch processing operation systems were used. Punch cards, paper tape, and magnetic tape were used as input and output devices. The computers in this generation used machine code as the programming language. The main features of the first-generation computers are: Vacuum tube technology Supported machine language only Generated a lot of head Huge size Non-portable Unreliable Very costly Slow input and output devices Need of AC Consumed a lot of electricity Some computers of the first generation ENIAC EDVAC UNIVAC IBM-701 IBM-650 Advantages: It made use of vacuum tubes, which were the only electronic component available during those days. These computers could calculate in milliseconds. Disadvantages: These were very big in size, weight was about 30 tons. These computers were very costly. It could store only a small amount of information due to the presence of magnetic drums. Very low work efficiency. Limited programming capabilities and punch cards were used to take inputs. Large amount of energy consumption. Not reliable; constant maintenance is required. Second-generation computers The period of the second generation was from 1959 to 1965. In this generation, transistors were used that were cheaper, consumed less power, were more compact in size, more reliable, and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as the primary memory and magnetic tape and magnetic disks as secondary storage devices. In this generation, assembly language and high-level programming languages like FORTRAN and COBOL were used. The computers used batch processing and a multiprogramming operating system. Second-generation computers (Transistors) The main features of the second generation computers are: Use of transistors Reliable in comparison to first-generation computers. Smaller size as compared to the first-generation computers. Generated less heat as compared to first-generation computers. Consumed less electricity than first-generation computers. Faster than first-generation computers. Still very costly. AC required. Supported machine and assembly languages. Some computers of this generation were: IBM 1620 IBM 7094 Honeywell 400 CDC 1604 CDC 3600 UNIVAC 1108 Advantages: Due to the presence of transistors instead of vacuum tubes, the size of the electron component decreased. This resulted in reducing the size of a computer as compared to first-generation computers. Less energy and does not produce as much heat as the first generation. Assembly language and punch cards were used for input. Lower cost than first-generation computers. Better speed, calculate data in microseconds. Better portability as compared to the first generation. Disadvantages: A cooling system was required. Constant maintenance was required. Only used for a specific purpose. Third-generation Computers The period of the third generation was from 1965 to 1971. The third generation was based on IC(Integrated Circuit) technology. IC technology made it possible to integrate a large number of circuit elements into a very small surface of silicon known as a ‘chip’. The IC was invented by Jack Kilby. In the third generation, IC technology further reduced the size, power requirements, and cost while increasing the speed, computing power, and reliability. In this generation, remote processing, time sharing, and multiprogramming operating systems were used. High-level languages (FORTRAN-II to IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68, etc.) were used during this generation. SSI (Small Scale Integration – few logic gates on a single chip), MSI (Medium Scale Integration – more than a hundred logic gates on a single chip), and LSI (Large Scale Integration – more than a thousand logic gates on a single chip) technologies were used to manufacture the third generation computers. The main features of the third generation are: IC used More reliable in comparison to the previous two generations Smaller size Generated less heat Faster Lesser maintenance Costly AC required Consumed lesser electricity Supported high-level language Some computers of the third generation were: IBM-360 series Honeywell-6000 series PDP (Personal Data Processor) ICL 2900 IBM-370/168 TDC-316 Advantages: These computers were cheaper compared to second-generation computers. They were fast and reliable. Use of IC in the compute rprovides the small size of the computer. IC not only reduces the size of the computer but also improves the performance of the computer as compared to previous computers. This generation of computers has a big storage capacity. Instead of punch cards, a mouse and a keyboard are used for input. They used an operating system for better resource management and used the concept of time-sharing and multiple programming. These computers reduce the computational time from microseconds to nanoseconds. Disadvantages: IC chips are difficult to maintain. The highly sophisticated technology is required for the manufacturing of IC chips. Air conditioning is required. Fourth-generation Computers The period of the fourth generation was from 1971 to 1980. It was used for very large-scale integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements with their associated circuits on a single chip made it possible to have microcomputers of the fourth generation. Fourth-generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to the Personal Computer (PC) revolution. In this generation, time sharing, real-time networks, and distributed operating systems were used. All the high-level languages like C, C++, DBASE, etc. were used in this generation. Advancements in IC technology created the computers of the fourth generation. VLSI (Very Large-Scale Integration) technology of ICs made it possible to integrate more than a thousand logic gates on a single chip. This made it possible to design the complete circuit of the Central Processing Unit (CPU) of a computer system within a single chip. The fourth-generation computer, which has VLSI chips as its brain, led to the development of very small but extremely powerful computers. Those computers were microcomputers having microprocessors as their CPU. The main features of the fourth generation are: VLSI technology used Very cheap Portable and reliable Use of PCs Very small size Pipeline processing No AC required The concept of the Internet was introduced Great developments in the fields of networks Computers became easily available Some computers of this generation were DEC 10 STAR 1000 IBM 4341 PDP 11 CRAY-1(Super Computer) CRAY-X-MP(Super Computer) Advantages: Faster in computation and size get reduced as compared to the previous generation of computers. Heat generated is negligible. Small in size compared to previous-generation computers. Less maintenance is required. All types of high-level languages can be used in these types of computers. Disadvantages: The microprocessor design and fabrication are very complex. Air conditioning is required in many cases due to the presence of ICs. Advanced technology is required to make the ICs. IC Chip Fifth-generation Computers The period of the fifth generation is 1980-till date. In this generation, VLSI technology became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components. This generation is based on parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch of computer science that interprets the means and methods of making computers think like human beings. All the high-level languages like C and C++, Java, .NET, etc., are used in this generation. The main features of the fifth generation are: ULSI technology. Development of true artificial intelligence. Development of Natural Language Processing. Advancement in Parallel Processing. Advancement in Superconductor technology. More user-friendly interfaces with multimedia features. Availability of very powerful and compact computers at cheaper rates. Some computer types of this generation are: Desktop Laptop Note Book Ultra Book Chrome Book Advantages: It is more reliable and works faster. It is available in different sizes and with unique features. It provides computers with more user-friendly interfaces with multimedia features. Disadvantages: They need very low-level languages. They may make the human brain dull and doomed. A computer can be classified by size and power as follows: Personal computer: Personal computers are small computers based on a microprocessor. A personal computer has a keyboard for inputting data, a monitor for output, and a storage device for saving data. Workstation: Workstations are usually more powerful than a personal computer. It has a more powerful microprocessor and a higher-quality monitor. Minicomputer: Minicomputers are multi-user computers capable of supporting from 10 to hundreds of users simultaneously. Mainframe computer: Mainframe computers are powerful multi-user computers capable of supporting many hundreds or thousands of users simultaneously. Supercomputer: Supercomputers are extremely fast computers that can perform hundreds of millions of instructions per second. Microcomputer: A personal computer, designed to meet the computer needs of an individual. Provides access to a wide variety of computing applications, such as word processing, photo editing, email, and the internet. computer fundamentals engineering subjects Microprocessor microprocessor