History of Computer | Generation of Computers | Classification of computer | Download Lecture in pdf form

History of Computer:

S#	Device Name	Year	Developer	Function
1	ABACUS	3000 B.C	Chinese	Addition and Subtraction
2	Napier Bones	1617	John Napier	Same
3	Mechanical Calculator	1642	Pascal	Same, multiplication, division
4	Multiplying Calculator	1694	Gottfried Leibnitz	Same Digits are introduced
5	Analytical Engine	1801	Charles Babbage	Same, Concept of Prints, Input Device Punch Chord: Fabrics Valen
6.	The Analytical Engine	The 1830s	Charles Babbage	All previous features, along with storage and control unit concept
7	Mechanical adding machine	1886	William	All previous features but it is not a commercial device
8	Electro-Mechanical Punch cord calculator	1890	Dr. Herman Hollerith	Modern data processing
9	Analogue Computer	1930	Bush	1st digital computer which takes analog data
10	MARK-I	1944	H.Aiken	The release is used instead of gates
11	ENIAC (Electro-Mechanical Integrator & Calculator	1946	JW.Mauchly	It is the 1st programmable computer that uses a Vaccum tube for storage
12	Same	1948	Same	Translators are used instead of vacuum tube
13	EDSAC (Electro delay storage automatic calculator)	1949	Same	1st storge and programmable computer, small size
14	EDVAC ( electro delay variable automatic computer)	1950	Same	Operating time decreased
15	UNIVAC ( universal vaccum automatic computer	1951	Speryrand	1st commercial computer
16	Whirl Wind-I	1953	MIT Company	Size minimized, Less heat production
17	Whirl Wind-II	1964		Introduction of integrated circuit
18	Mini-Computer	1965		Size Minimized
19	LSI ( Large Scale integration)	The 1970s		1st microcomputer
20	Micro Computer	1975		Desktop computer
		1980		CPU on a single chip
		The 1980s		Super chip development
		The 1990s		Development of A.I

Generation of Computer:

1^st Generations: (1942-1959):

Storage device:- Vaccum tube & Magnetic core.

Beginning of Computer

2^nd Generation(1959-1965)(Main Frame Computer):

Storage Device:- Vaccum tubes are replaced by transistors.

Features:

• Small Size,
• High Processing Speed,
• Small Cooling System,
• Required comparatively less heat production,
• Programming features developed.

3^rd Generation (1965-1970)(Mini Computer):

Features:

• Integration of Circuits,
• Smaller in Size,
• The time-sharing concept developed.

4^th Generation (1970-1980)(Micro Computer e.g Desktop Computer, PSs):

Features:

• Large Scale Integration (LSI),
• Very large scale integration (VLSI),
• Ultra very large scale integration,
• Smallest Size,
• Portability,
• Multi-Processing

5^th Generation (1980-Onward):

• Artificial Intelligence (e.g. Robot)

Classification of Computer:

1.    Classification of computer w.r.t size:

i.    Main Frame Computer:

• Large in size,
• Large in memory,
• Most Powerful,
• Most expensive,
• Design for data of huge business
• Scientific laboratories
• International markets and defense purposes
• Example: IBM4381, ICL2900

ii.    Mini Computer:

• Smaller in size as compared to the mainframe computers and large in size as compared to microcomputers.
• Smaller in memory as compared to the mainframe computers and large in-memory as compared to microcomputer
• Less expensive
• Design for the data of scientific research, for industrial purposes,
• And for small businesses.
• Example: IBM36, PRIME 9755

iii.    Micro Computer:

• Smallest in size
• Smallest in memory
• Least expensive
• Design for personal use
• Small scale domestic business application
• Example: Pentium 1,2,3,4,5 etc

2.    Classification w.r.t purpose:

i.    General Purpose Computer:

The type of computer which is designed to perform all kinds of tasks is called a General purpose computer.

Features:

• perform a variety of jobs/tasks,
• The general-purpose computer is versatile
• Slow in processing
• Less efficient

ii.    Special Purpose computer:

Those computers that perform only one specific task are called Special-purpose computers, also called a dedicated computer.

Features:

• Design to perform on;y on a particular task.
• Fast in processing
• Most efficient
• Example Computer in ATM,
• Computer in traffic control lights,
• Diagnostic computers in the medical field

3.    Classification w.r.t Nature/ Data:

i.    Digital Computer:

Which takes digital input data and produces a digital output

Features:

• They are general-purpose machine
• They have a large internal memory
• Or perform all arithmetical logical operations
• These are precise b/c they provide the exact answer to a specific problem,
• They are easy to use.

ii.    Analog Computer:

Which takes analog input and as a result produces analog output,

Features:

• They are mostly mechanical or electrical machines that perform tasks like addition, subtraction, multiplication, and division.
• They are designed for a specific purpose
• The output of an analog computer can be expressed in the form of graphics, or on paper.
• They are the 1^st generation of computers.

iii.    Hybrid Computer:

Which take both digital and analog data and produce digital and analog output data respectively.

Features:

• It can process both continuous and discrete data
• It has the capability to convert one type of data into another
• It has a highest compared to analog and digital computer
• It is a combination of qualities of analog as well as a digital computer.