GENERATIONS	MACHINE/DEVICE	YEAR	INFORMATION
G4	The Microprocessor	1971	This generation can be characterized by both the jump to monolithic integrated circuits(millions of transistors put onto one integrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer).  By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers.  Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers.         However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor.  Ted Hoff, employed by Intel (Robert Noyce's new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer.  The microprocessor was made to be used in calculators, not computers.  It led, however, to the invention of personal computers, or microcomputers. It wasn't until the 1970's that people began buying computer for personal use.  One of the earliest personal computers was the Altair 8800 computer kit.  In 1975 you could purchase this kit and put it together to make your own personal computer.  In 1977 theApple II was sold to the public and in 1981 IBM entered the PC (personal computer) market.
G5	Vlsi/Ulsi	1984-1990	In this period, computer technology achieved more superiority and parallel processing, which was until limited to vector processing and pipelining, where hundreds of processors could all work on various parts of a single program. There were introduction of systems like the Sequent Balance 8000, which connected up to twenty processors to one shared memory module. This machine was as competent as the DEC VAX-780 in the context that it had a general purpose UNIX system and each processor worked on a different user's job. On the other hand, INTEL IPSC-I or Hypercube, as it was called, connected each processor to its own memory and used a network interface to connect the processors. With the concept of distributed network coming in, memory posed no further problem and the largest IPSC-I was built with 128 processors. Towards the end of the fifth generation, another parallel processing was introduced in the devices, which were called Data parallel or SIMD. In this system, all the processors operate under the instruction of a single control unit. In this generation semiconductor memories became the standard were pursued vigorously. Other developments were the increasing use of single user workstations and widespread use of computer networks. Both wide area network (WAN) and local area network (LAN) developed at an incredible pace and led to a distributed computing environment. RISC technology i.e. a particular technique for the internal organization of CPU and the plunging cost of RAM ushered in huge gains in computational power of comparatively cheaper servers and workstations. This generation also witnessed a sharp increase in both quantitative and qualitative aspects of scientific visualization.