The generations of computers is a change of technology used for manufacturing computer. Each generation is designed based on new technological development, resulting in better, cheaper, and smaller computers that are more powerful, faster, and efficient than their predecessors.
Generation of computer mainly focus on hardware technology, but nowadays it focuses on following factors as well:
- The technology used by them (hardware and software),
- Computing characteristics (speed, number of instructions executed per second),
- Physical appearance, and their applications.
First Generations of Computer (1946 to 1959): Using Vacuum Tubes
The first generation of computers used vacuum tubes for processing and magnetic drums for memory. The input to the computer was through punched cards and paper tapes. The output was displayed as printouts.
These generation computers are very expensive and large in size, which requires special housing.
Features of the First generations of computer:
- The instructions were written in machine language that uses 0’s and 1’s for coding of the instructions.
- It could solve one problem at a time.
- The computation time was in milliseconds.
- Those computers are big and required a large room for installation.
- They are used for scientific applications as they were the fastest computing device of their time.
- Those computers consist of a large number of vacuum tubes and thus generated a lot of heat. They consumed a great deal of electricity and were expensive to operate.
- The machines were prone to frequent malfunctioning and required constant maintenance. Since first-generation computers used machine language, they were difficult to program.
Example:- Automatic Computer (UNIVAC), Electronic Numerical Integrator And Calculator (ENIAC), and Electronic Discrete Variable Automatic Computer (EDVAC).
Second Generations of Computer (1959 to 1965): Using Transistors
In a second-generation, vacuum tubes were replaced by transistors. Transistors are smaller than vacuum tubes, faster, cheaper, energy-efficient, and reliable.
Due to the use of transistors, the computer has become smaller in size and cheaper. It used magnetic core technology for primary memory.
They used magnetic tapes and magnetic disks for secondary storage. The input was given through punched cards and the output using printouts, where instructions were stored in the memory of the computer. One transistor was able to replace 1000 vacuum tubes.
Features of the Second generations of computer:
- The instructions were written using the assembly language. Assembly language uses mnemonics like ADD for addition and SUB for subtraction for coding of the instructions. It is easier to write instructions in assembly language, as compared to writing instructions in machine language.
- High-level programming languages, such as early versions of COBOL and FORTRAN were also developed during this period.
- Computation time was in microseconds.
- Transistors were smaller in size compared to vacuum tubes. Thus, the size of the computer was also reduced.
- Second-generation computers generated a lot of heat but much less than first-generation computers. They required less maintenance than the first generation computers.
- They used magnetic disks as secondary memory.
Examples:- PDP-8, IBM 1401, ICL 1300, and CDC 1604.
Third Generation (1965 to 1971): Using Integrated Circuits
The third generation computers used the Integrated Circuit (IC) chips (LSI-Large scale integration) as the processing/memory device. In an IC chip, multiple transistors are placed on a silicon or semiconductor chip.
IC chip increased the speed and the efficiency of the computer rather than transistors.
Computers are now further reduced in size. The keyboard and monitor were used to interact with the users. This generation computer used to mass storage: Floppy Disk, Hard Disk, Tape unit, etc.
Features of the Third generations of computer:
- The keyboard and the monitor were interfaced through the operating system. Operating systems run multiple jobs at the same time.
- This generation computer’s computation time was in nanoseconds.
- The size of these computers was quite small.
- Computers were produced commercially and were smaller and cheaper than their predecessors.
- They supported high-level language.
- They used a semi-conductor device as primary storage.
- The third generation computers used less power and generated less heat than the second generation computers.
- The maintenance cost and other costs are reduced.
- The computer used high-level programming languages such as FORTRAN, COBOL, etc
Examples:- IBM 360, ICL-1901 and PDP 11.
Fourth Generation of Computer
(1971 to present): Using Microprocessors
These generation computers use the Large Scale Integration (LSI) and the Very Large Scale Integration (VLSI) technology.
Where 1000’s transistors are integrated on a small silicon chip. These are very cheaper, smaller, and faster than other generations.
The microprocessor is a chip containing millions of transistors and components, and, designed using LSI and VLSI technology.
Semiconductor memory replaced the earlier magnetic core memory, resulting in fast random access to memory. Secondary storage devices like magnetic disks became smaller in physical size and larger in capacity.
The computers were linked to form networks that led to the emergence of the Internet. This generation also saw the development of pointing devices like mouse, and handheld devices.
Features of the fourth generations of computer:
- Today’s computers support GUI (Graphical User Interface). GUI is a user-friendly interface that allows users to interact with the computer via menus and icons.
- High-level programming languages are used for the writing of programs.
- The computation time is in picoseconds.
- They are smaller than the other generation computers. Hence, they are portable & Reliable.
- They became widely available for commercial purposes.
- IC is used in the form of VLSI (Microprocessor) as the main component.
- The size of the computer was reduced to desktop, laptop, and notebook.
- They use object-oriented programming language.
- The components of the computer like the Central Processing Unit (CPU) and memory were located on a single chip.
Examples:- The Intel 4004 chip (world’s first microprocessor), intel 8085, etc.
In 1981, IBM introduced the first computer for home use.In 1984, Apple introduced the Macintosh.
Fifth Generation of Computer (Present and Next): Using Artificial Intelligence
There is no any fix direction of the fifth generations of computers. But scientists are working hard to develop computers that are capable of self-learning with self-organization capability using Artificial Intelligence.
This generation of computers uses Ultra Large Scale Integrated (ULSI) IC chips or bio-chips that can store millions of components on a single chip and large memory requirements.
This generation of computers uses parallel processing that allows several instructions to be executed in parallel. The Intel dual-core microprocessor uses parallel processing.
Bio-Chips will be made from biological molecules(DNS) rather than semiconductor.
Similarly, AI tries to simulate the human way of thinking and reasoning. Artificial Intelligence includes areas like Expert System (ES), Natural Language Processing (NLP), speech recognition, voice recognition, robotics, etc.
Features or fifth generations of computer-
- BIO chip will be used as the main component of the fifth generation of computers.
- They will have artificial intelligence.
- They will have huge processing power & gigantic memory space.
- They will provide a natural computer interface.
- They will use multi/parallel processing.
- Fifth generations of computers will understand Natural Languages & Body languages as well.