We will discuss the generations of computer in terms of

  • The technology used by them (hardware and software),
  • computing characteristics (speed, i.e.,number of instructions executed per second),
  • physical appearance, and
  • their applications.

Fourth Generation (1971 to present): Using Microprocessorsprocessor intel i7

  • Hardware Technology They use the Large Scale Integration (LSI) and the Very Large Scale Integration (VLSI) technology. Thousands of transistors are integrated on a small silicon chip using LSI technology. VLSI allows hundreds of thousands of components to be integrated in a small chip. This era is marked by the development of microprocessor. Microprocessor is a chip containing millions of transistors and components, and, designed using LSI and VLSI technology. A microprocessor chip is shown in Figure 1.7. This generation of computers gave rise to Personal Computer (PC). Semiconductor memory replaced the earlier magnetic core memory, resulting in fast random access to memory. Secondary storage device like magnetic disks became smaller in physical size and larger in capacity. The linking of computers is another key development of this era. 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.
  • Software Technology Several new operating systems like the MS-DOS and MS-Windows developed during this time. This generation of computers supported Graphical User Interface (GUI). GUI is a user-friendly interface that allows user to interact with the computer via menus and icons. High-level programming languages are used for the writing of programs.
  • Computing Characteristics The computation time is in picoseconds.
  • Physical Appearance They are smaller than the computers of the previous generation. Some can even fit into the palm of the hand.
  • Application They became widely available for commercial purposes. Personal computers became available to the home user.
  • Examples The Intel 4004 chip was the first microprocessor. The components of the computer like Central Processing Unit (CPU) and memory were located on a single chip. In 1981, IBM introduced the first computer for home use. In 1984, Apple introduced the Macintosh. 

The microprocessor has resulted in the fourth generation computers being smaller and cheaper than their predecessors. The fourth generation computers are also portable and more reliable. They generate much lesser heat and require less maintenance compared to their predecessors. GUI and pointing devices facilitate easy use and learning on the computer. Networking has resulted in resource sharing and communication among different computers.