Resaerch

Computer

First Generation (1940 – 1956) – Vacuum Tubes
These early computers used vacuum tubes as circuitry and magnetic drums for memory. As a result they were enormous, literally taking up entire rooms and costing a fortune to run. These were inefficient materials which generated a lot of heat, sucked huge electricity and subsequently generated a lot of heat which caused ongoing breakdowns.
These first generation computers relied on ‘machine language’ (which is the most basic programming language that can be understood by computers). These computers were limited to solving one problem at a time. Input was based on punched cards and paper tape. Output came out on print-outs. The two notable machines of this era were the UNIVAC and ENIAC machines – the UNIVAC is the first every commercial computer which was purchased in 1951 by a business – the US Census Bureau.
Second Generation (1956 – 1963) – Transistors
The replacement of vacuum tubes by transistors saw the advent of the second generation of computing. Although first invented in 1947, transistors weren’t used significantly in computers until the end of the 1950s. They were a big improvement over the vacuum tube, despite still subjecting computers to damaging levels of heat. However they were hugely superior to the vacuum tubes, making computers smaller, faster, cheaper and less heavy on electricity use. They still relied on punched card for input/printouts.
The language evolved from cryptic binary language to symbolic (‘assembly’) languages. This meant programmers could create instructions in words. About the same time high level programming languages were being developed (early versions of COBOL and FORTRAN). Transistor-driven machines were the first computers to store instructions into their memories – moving from magnetic drum to magnetic core ‘technology’.
The early versions of these machines were developed for the atomic energy industry.
Third Generation (1964 – 1971) – Integrated Circuits
By this phase, transistors were now being miniaturized and put on silicon chips (called semiconductors). This led to a massive increase in speed and efficiency of these machines. These were the first computers where users interacted using keyboards and monitors which interfaced with an operating system, a significant leap up from the punch cards and printouts. This enabled these machines to run several applications at once using a central program which functioned to monitor memory.
As a result of these advances which again made machines cheaper and smaller, a new mass market of users emerged during the ‘60s.
Fourth Generation (1972 – 2010) – Microprocessors
This revolution can be summed in one word: Intel. The chip-maker developed the Intel 4004 chip in 1971, which positioned all computer components (CPU, memory, input/output controls) onto a single chip. What filled a room in the 1940s now fit in the palm of the hand. The Intel chip housed thousands of integrated circuits. The year 1981 saw the first ever computer (IBM) specifically designed for home use and 1984 saw the Macintosh introduced by Apple. Microprocessors even moved beyond the realm of computers and into an increasing number of everyday products.
The increased power of these small computers meant they could be linked, creating networks. Which ultimately led to the development, birth and rapid evolution of the Internet. Other major advances during this period have been the Graphical user interface (GUI), the mouse and more recently the astounding advances in lap-top capability and hand-held devices.

Fifth Generation (2010) – Artificial Intelligence
Computer devices with artificial intelligence are still in development, but some of these technologies are beginning to emerge and be used such as voice recognition. AI is a reality made possible by using parallel processing and superconductors. Leaning to the future, computers will be radically transformed again by quantum computation, molecular and nano technology. The essence of fifth generation will be using these technologies to ultimately create machines which can process and respond to natural language, and have capability to learn and organize themselves. Artificial Intelligence includes: * Games Playing: programming computers to play games such as chess and checkers * Expert Systems: programming computers to make decisions in real-life situations (for example, some expert systems help doctors diagnose diseases based on symptoms) * Natural Language: programming computers to understand natural human languages * Neural Networks: Systems that simulate intelligence by attempting to reproduce the types of physical connections that occur in animal brains

Components of Computer
For computer to work, there are different components that work for carrying out operations. Below is list of components of computer. * Motherboard: Motherboard is the primary circuit board. All the other components can be connected and removed with motherboard as per requirement. Some components which are included in motherboard architecture such as the system clock which stores information when the system is powered off. * Central Processing Unit: This is the most important part of computer. It is abbreviated as CPU and is also called brain of computer. The CPU consists the microprocessor which is heart of all operation conducted by computer. Central processing unit is divided into three main component
Tyson, Crawford (2011) states “That microprocessor is the heart of all the PC’s operations, and the performance of both hardware and software rely on the processor’s performance.” * Memory unit: The memory unit is used to store the input and output data. The memory is categorized as temporary memory and permanent memory * Random Access Memory: Random access memory is abbreviated as RAM. It provides buffer space for data required by CPU. It helps in decreasing the idle time of CPU and increasing its performance. This is temporary memory. * Read only memory: Read only memory is abbreviated as ROM. This memory is permanent memory which contains data that needs to be stored permanently. Computer Programs such as Boot Strap program is stored in ROM. * Arithmetic Logic Unit: Arithmetic logic unit is abbreviated as ALU. Here all the processing such as arithmetic and logical calculations are conducted. * Control Unit: The control unit controls all the components and processing of the computer system. The unit gives signals to other parts what action will be taken at what phase of time. The control unit is also responsible for fetching and decoding the required data and sent instructions for processing/ other operations. * Input/output Device: The input and output devices are used to input and output data to and from the computer. Keyboard is most popular input device and monitor is an example of output device.

http://www.btob.co.nz/article/five-generations-computers
http://myassignmenthelp.info/assignments/tag/five-generations-of-computers/