Computers have a long history of development. Each stage is described as a new generation and is characterized by fundamental changes in the technology used to operate computers. The five stages, or generations, are as follows:
First generation computers used, in addition to circuitry involving vacuum tubes, magnetic memory storage drums. Often so large that they took up whole rooms, they were expensive to run and used huge amounts of electricity. Solving problems was limited to one at a time. These computers used machine-language put in through punched cards and output came in the shape of print-outs.
The second computer generation utilized transistors instead of vacuum tubes and so-called magnetic core technology for memory. This resulted in smaller, faster and more energy efficient computers. Information was still entered using punched cards and output was still printed, too however. Input language moved on to symbolic languages. Early versions of the FORTRAN and COBOL programming languages were developed.
Integrated circuits heralded the arrival of the third computer generation and drastically increased the efficiency and speed of computers. Users now interacted with the computer via keyboards and monitors. The operating system allowed running of many different applications, with a central program monitoring memory.
The fourth computer generation uses microprocessors. IBM offered the first home-use computer in 1981, closely followed by Apple's Macintosh in 1984. As these small processors were becoming more powerful, they could be linked into networks, ultimately leading to the arrival of the Internet. This generation saw the development of the mouse, GUIs and hand-held gadgets.
The fifth generation, artificial intelligence, is still being developed, although some early applications, such as voice recognition, are already in use. The aim is to develop devices capable of understanding natural language input, learning and self-organization.
