History and Generation of Computers

The word Computer in earlier times meant a person who performed calculations or computations. With years its definition changed to a machine that performs calculations. It can perform all type of mathematical and logical operations; it can accept data, store data, retrieve data, process data and produce output.

Charles Babbage was known as father of computer. He invented two machines in 1822 introduced Difference Engine and in 1834 introduced Analytical engine.

	Difference Engine		Charles Babbage	First automatic mechanical calculator
	Analytical Engine		Charles Babbage	Mechanical general-purpose computer
	Z1		Konrad Zuse	World’s first freely programmable computer
	MARK-1		Konrad Zuse	First Freely programmable Computer
	ENIAC		John  W.  Mauchly  and  J.	First  general  purpose programmable  electronic
			Presper Eckert	computer
	EDSAC		John von Neumann	First computer to store program
	EDVAC		John  W.  Mauchly  and  J.	Binary serial computer
			Presper Eckert
	UNIVAC		John  W.  Mauchly  and  J.	First general-purpose computer for commercial use
			Presper Eckert
	Intel 4004		Intel	First commercially available microprocessor by
				Intel, a 4-bit CPU
	LISA(Local Integrated		Apple Inc.	First commercial personal computers to have a GUI
	Software
	Architecture)
	Dataphone		AT&T	First AT&T Commercial modem
	ARPANET		United States Department	Early  packet  switching  network  and  the  first
			of Defence	network to implement the protocol suite TCP/IP.
	NEXUS	Browser	Tim Berners-Lee	First  Web  Browser  was  WorldWideWeb  later
	(WorldWideWeb)			named Nexus. The first commonly available web
				browser with a graphical user interface was Erwise.
	Six Degrees			First social networking/ social media site

ENIAC was the first digital computer and it was invented by J.Presper Eckert and John Mauchly at the University of Pennsylvania and began construction in 1943. It uses 18000 vacuum tubes as a storing device. They were also founders of the first computer company, it was initially named Electronic Controls Company which was later changed to Eckert– Mauchly Computer Corporation, and released a series of mainframe electronic digital stored-program computer under the name of UNIVAC.

MIT introduces the whirlwind machine (first computer with RAM) on March 8, 1955.

	Subject		1st generation		2nd generation	3rd generation		4th generation	5th generation
	Period		1940-1956		1956-1963		1964-1971	1971-present	present & beyond
	Circuitry		Vacuum tube		Transistor		Integrated	Microprocessor	ULSI (Ultra Large
							chips (IC)	(VLSI)	Scale Integration)
									technology
	Memory Capacity		20 KB		128KB		1MB	Semiconductor type	VLSI and ULSI
								and very high
	Processing Speed		300 IPS inst. Per		300 IPS		1MIPS(1	Faster than 3rd	Very fast
			sec.			million inst. Per		generation
							sec.)
	Programming		Assembly		High level		C,C++	C,C++,Java	All the Higher level
	Language		Language		language				languages,
					(FORTRAN,				Neural networks,
					COBOL, ALGOL)
	Example of		UNIVAC,		IBM 1401, IBM	IBM 360 series,		Pentium series	Artificial
	computers		EDVAC		7094,		1900 series	Multimedia,	Intelligence,
					CDC 3600,D			Stimulation	Robotics
					UNIVAC 1108