In this section, we will discuss what are the generations of computers, the timeline of each generation, and the technology used in each generation.
What are the Generations of Computer
The Generations of Computer refers to the change in technological advancement in the field of computers from the birth of computers to the latest technology. The generations are classified according to the evolution of the technology from the beginning till date.
They are categorized into five different generations. They are as follows.
- First Generation (1946-1959): The age of vacuum tubes.
- Second Generation(1959-1965): The semiconductor transistor replaces vacuum tubes.
- Third Generation (1965-1971): Integrated Circuits (ICs).
- Fourth Generation (1971-1980): VLSI (very large integration).
- Fifth Generation (1980-till date and beyond): ULSI(ultra large scale integration)Artificial intelligence, Robotics.
First Generation (1946-1959)
Vacuum tubes were used in First Generation computers as major active devices in circuitry and magnetic drums were used for memory. The input to the system was provided through paper tapes and punched cards. Machine languages were used to write instructions for the computer. Since a large number of vacuum tubes was used for circuitry; it was bulky in size and required large area to set up the system. These vacuum tubes generate lots of heat and consume lots of electricity. These tubes were burned out frequently due to overheating. The performance was also reliable and are too expensive to operate the system.
Examples of First Generation computers are: ENIAC (Electronic Numerical Integrator and Calculator), EDVAC(Electronic Discrete Variable Automatic Computer), and UNIVAC (Universal Automatic Computer)
Second Generation (1959-1965)
The invention of semiconductor transistors revolutionized the development of computer technology. The transistor was smaller in size, generate less heat, and consume less electricity than its predecessor, vacuum tubes of First Generation. Transistor was faster than vacuum tubes. It used magnetic core as primary memory; and magnetic tape and magnetic disc as secondary memory. Instructions were written in machine language as well as assembly language. Batch processing and Multiprogramming Operating system were used as system software. The concept of the stored-program has evolved from second-generation where instructions were stored in memory.
Examples of second generation are: UNIVAC 1108, CDC3600, CDC1604, IBM7094, IBM1620 etc.
Third Generation (1965-1971)
The integrated chips (ICs) were introduced in the Third Generation. Integrated chips can hold multiple numbers of transistors in a single chip. The size of the computer drastically reduced due to the use of an IC chip. Also, the speed and efficiency of the computer of the Third Generation increased as compared to that of the Second Generation. High-level languages were used to give instructions to the computer. This generation of computers was more reliable, compact, and required less maintenance. Examples of the Third generation are IBM-260 series, Honeywell-6000, PDP (Personal Data Processor), IBM-270/168, TDC-316, etc.
Fourth Generation (1971-1980)
The size of the integrated chips was getting smaller after the large scale integration (LSI) and very large integration (VLSI) technique evolved. VLSI technique contained almost 5000 transistors in a single chip. Microprocessors were developed using the VLSI technique. The size of the computer dramatically reduced and it has become more compact, reliable, generate less heat, and consumes very less electricity. High-level languages like C, C++, and DBASE are used for programming. Personal computers came into existence due to smaller sizes. Semiconductor memory was used in place of magnetic core memory. The size of the secondary memory reduced and storage capacity was increased. There was a major development in the field of networking and the concept of the internet evolved during the Fourth Generation.
Examples of fourth-generation computers are DEC10, PDP11, STAR1000, CRAY-1 Supercomputer, etc.
Fifth Generation (1980-till date and beyond)
There was a huge development in the field of computer technology for the last ten decades. In the 1950s, the computers were so large and bulky; as the technology changes, the size drastically reduced and come with more reliability and compact in size. Till then, the computer was allowed to perform specific task, until the user tells it to do. But after the development of artificial intelligence, a computer can think like human beings. The software was developed to simulate human thinking and reasoning. Parallel processing emerged as the major development where CPUs are allowed to execute several instructions in parallel which increases the processing speed and handles the multiple tasks simultaneously. High-level languages like C, C++, .Net, Object-Oriented Programming, Java, Natural Language Processing are used in this generation.