Fourth Generation Computers (1971-Present)

Fourth generation computers started around 1971 by using large scale of integration (LSI) in the construction of computing elements. LSI circuits built on a single silicon chip called microprocessors. A microprocessor contains all the circuits required to perform arithmetic, logic and control functions on a single chip. Because of microprocessors, the fourth generation includes more data processing capacity than equivalent-sized third generation computers. Due to the development of microprocessor it is possible to place computer‟s central processing unit (CPU) on single chip. These computers are called microcomputers. Later very large scale Integrated (VLSI) circuits replaced LSI circuits.
What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004chip, developed in 1971, located all the components of the computer – from the central processing unit and memory to input/output controls – on a single chip

The major innovations in this generation were the development of microelectronics and the different areas in computer technology such as multiprocessing, multiprogramming, time-sharing, operating speed, and virtual storage. During this period, high speed vector processors changed the scenario of high performance computing. Mostly microcomputers and workstations were introduced for time shared mainframe computers. Thus the computer which was occupying a very large room in earlier days can now be placed on a table. The personal computer is a Fourth Generation Computer. It is the period when evolution of computer networks also took place.

Examples: Apple II, Alter 8800