Five basic operations of a computer

 Inputting:
The process of entering data and instructions into the computer system
 Storing:
 Saving data and instructions to make them readily available for initial or additional processing whenever required
 Processing:
 Performing arithmetic operations (add, subtract, multiply, divide, etc.) or logical operations (comparisons like equal to, less than, greater than, etc.) on data to convert them into useful information
Outputting:
The process of producing useful information or results for the user such as a printed report or visual display
Controlling:
Directing the manner and sequence in which all of the above operations are performed

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Generations of computer

·         “Generation”in computer talk is a step in technology.  It provides a framework for the growth of computer industry

·         Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software

·         Till today, there are five computer generations

Generation       (Period)	Hardware Technology	Software Technology	Characteristics	Some representative System
First (1942-1955)	Vacuum tubes         Electromagnetic relay memory           Punched cards secondary storage	Machine and assembly languages           Stored program concept          Mostly scientific applications	Bulky in size          Highly unreliable          Limited commercial use and costly          Difficult commercial production          Difficult to use	·        ENIAC ·         EDVAC ·          EDSAC ·         UNIVAC I ·          IBM 701
Second (1955-1964)	Transistors   Magnetic cores memory   Magnetic tapes   Disks for secondary storage	Batch operating system   High-level programming languages   Scientific and commercial applications	Faster, smaller, more reliable and easier to program than previous generation systems   Commercial production was still difficult and costly	Honeywell 400   IBM 7030   CDC 1604  UNIVAC LARC
Third (1964-1975	ICs with SSI and MSI technologies   Larger magnetic cores memory  Larger capacity disks and magnetic tapes secondary storage   Minicomputers; upward compatible family of computers	Timesharing operating system  Standardization of high-level programming languages  Unbundling of software from hardware	Faster, smaller, more reliable, easier and cheaper to produce   Commercially, easier to use, and easier to upgrade than previous generation systems   Scientific, commercial and interactive on- line applications	IBM 360/370   PDP-8   PDP-11   CDC 6600
Fourth (1975-1989)	ICs with VLSI technology  Microprocessors; semiconductor memory   Larger capacity hard disks as in-built secondary storage  Magnetic tapes and floppy disks as portable storage media   Personal computers   Supercomputers based on parallel vector processing and symmetric multiprocessing technologies § Spread of high-speed computer networks	Operating systems for PCs with GUI and multiple windows on a single terminal screen   Multiprocessing OS with  concurrent programming languages   UNIX operating system with C programming language   Object-oriented design and programming   PC, Network-based, and super-computing applications	Small, affordable, reliable, and easy to use PCs   More powerful and reliable mainframe systems and supercomputers   Totally general purpose machines  Easier to produce commercially   Easier to upgrade   Rapid software development possible	IBM PC and its clones   Apple II  TRS-80   VAX 9000   CRAY-1   CRAY-2  CRAY-X/M
Fifth (1989- Present)	ICs with ULSI technology   Larger capacity main memory, hard disks with RAID support   Optical disks as portable read-only storage media   Notebooks, powerful desktop PCs and workstations   Powerful servers,  supercomputers   Internet   Cluster computing	Micro-kernel based, multithreading, distributed OS   Parallel programming libraries like MPI & PVM   JAVA   World Wide Web   Multimedia, Internet applications   More complex supercomputing applications	Portable computers   Powerful, cheaper, reliable, and easier to use desktop machines   Powerful supercomputers   High uptime due to hot-pluggable components  Totally general purpose machines   Easier to produce commercially, easier to upgrade   Rapid software development possible	IBM notebooks   Pentium PCs   SUN Workstations   IBM SP/2   SGI Origin 2000   PARAM 10000

First Generation Computer

Second Generation Computer

Third Generation Computer

Fourth Generation Computer

Five Generation Super computer

Five Generation Robot

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Evolution of computer & Some of earlier computer's

                   Evolution of Computers

·         Blaise Pascal invented the first mechanical adding machine in 1642

·         Baron Gottfried Wilhelm von Leibniz invented the first calculator for multiplication in 1671

·         Keyboard machines originated in the United States around 1880

·         Around 1880, Herman Hollerith came up with the concept of punched cards that were extensively used as input media until late 1970s

·         Charles Babbage is considered to be the father of modern digital computers

·          He designed “Difference Engine “in 1822

·          He designed a fully automatic analytical engine in 1842 for performing basic arithmetic functions

·          His efforts established a number of principles that are fundamental to the design of any digital computer

Some of well known earlier computers

·          The Mark I Computer (1937-44)

·         The Atanasoff-Berry Computer (1939-42)

·          The ENIAC (1943-46) § The EDVAC (1946-52)

·          The EDSAC (1947-49)

·          Manchester Mark I (1948)

·          The UNIVAC I (1951)

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Characteristics of computer

                                    Characteristics of computer

1) Automatic: Given a job, computer can work on it automatically without human interventions.

2) Speed: Computer can perform data processing jobs very fast, usually measured in microseconds (10-6), nanoseconds (10-9), and picoseconds (10-12).

3) Accuracy: Accuracy of a computer is consistently high and the degree of its accuracy depends upon its design. Computer errors caused due to incorrect input data or unreliable programs are often referred to as Garbage- In-Garbage-Out (GIGO).

4) Diligence: Computer is free from monotony, tiredness, and lack of concentration. It can continuously work for hours without creating any error and without grumbling.

5) Versatility: Computer is capable of performing almost any task, if the task can be reduced to a finite series of logical steps.

6) Power of Remembering: Computer can store and recall any amount of information because of its secondary storage capability. It forgets or looses certain information only when it is asked to do so.

7) No I.Q.: A computer does only what it is programmed to do. It cannot take its own decision in this regard.

8) No Feelings: Computers are devoid of emotions. Their judgments based on the instructions given to them in the form of programs that are written by us (human beings).

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Data processing

Data Processing

The activity of processing data using a computer is called data processing

·         Data

·         Capture Data

·         Manipulate Data

·         Output Results

·         Information

Data is raw material used as input and information is processed data obtained as output of data processing.

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What is Computer?

The word computer comes from the word “compute”, which means, “to calculate”

 Thereby, a computer is an electronic device that can perform arithmetic operations at high speed

 A computer is also called a data processor because it can store, process, and retrieve data whenever desired

or 

Computer is an electronic device which help human do do work fast and aquatically. 

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