Computer knowledge

History of Computer

 Earlier computers were costly and only large organizations could afford them. But in recently years, new technologies and advancements in the field of Information Technology (IT) have made computers within reach of small organization and individual also. The computers are divided into five generations. These are described has follows:-

a)      First Generation

b)      Second Generation

c)      Third Generation

d)     Fifth Generation

First Generation

 Eckert and Mauchly established a new company in 1946. This company was incorporated as the, UNIVAC Division of Remington Rand in 1949. The first machine, UNIVAC-1 built by this company was made operational in 1951 at the Bureau of Census. This machine used magnetic medium for data input and output. It was so rugged that it could be run 24 hours a day and worked successfully till 1963. A similar machine was produced in bulk and put to business application in 1954. These machines are known as the first generation computers. These computers used valve technology and not very high reliability. Some Popular computers are:

Second Generation

 With the advent of transistor technology, second generations of computer come into existence. These computers were smaller in size, more reliable and highly efficient. These machines used English like language known as high level language (HLL) for ease of operation and application in business and scientific analysis. Many American and European companies manufactured these machines. One of them, the (international Business Machines) IBM-1401 was the most popular. Some popular computers are:

Third Generation

  In the sixties, the integrated circuits popularly known as Integrated Circuit (ICs) came in the field of microelectronics. Computers that uses a large junk of electronic components were substantially benefited both from the point of price reduction as well as size reduction. Moreover, these machines consumed less power and were highly reliable. These machines used more versatile programs like real time operating system, multiprogramming techniques and database management. IBM 370 is one of the most popular machines of this generation. Some popular computers are:

Fourth Generation

 The fourth generation computers are primarily based on microprocessors comprising Large Scale Integration (LSI) chips and Very Large Scale (VLSI) chips. The invention of microprocessor chip has created a revolution in the reduction of price and size of the generation machines. These machines have following advantages over other generations:

a)      These machines are much faster, less expensive and have greater data processing capacity than equivalent size third generation computers.

b)      These computers use advanced techniques to feed data, and to bring out processed data for used for out side world. They can even be connected with the satellite communication links to transfer information from the part of world to other part of the world and very high speed.

c)      These machines use advance application software packages, such as process controllers, computers Aided design (CAD), electronic spread sheet (Microsoft Excel) and relational Data based management (oracle 9i). Because of this, these machines of table’s size typewriters have the same power as was available in very large computers of the third generation.

Some popular computers are:

1.      DEC10

2.      STAR1000

3.      PDP 11

4.      CRAY-1(Super Computer)

5.      CRAY-X(Super Computer)

Fifth Generation  

 The period of fifth generation is 1980 till date. In the fifth generation, the VLSI Technology became very large scale integrated circuits, resulting in the production of microprocessor chips having 10 million electronic components. This Generation is based on parallel processing hardware & AI software. AI is an emerging branch in computer science which interprets means and method of making computer think like human being. All the high level languages like C & C++, Java, .Net etc. are used in this generation. Some popular Computers are:

                                                              

Introduction of Internet

 The internet has been in a state of continuous evolution since the late 1960s. Some simplified descriptions of the internet, are “a large computer network” or “network of networks”, “an instantaneous and global messaging system”. However, the Internet has become much more than this. It has grown into an important infrastructure supporting widespread, multidisciplinary community. This community now consists of students, scientists and researcher, large corporations, non-profit organizations, government agencies, and individual consumers.

 

Internet

 Internet is an immensely complex combination of thousands of technologies and dozens of services used by tens of millions of people around the world each day. Internet is thus, a network of networks. The Internet is a network of thousands of computer networks. Every network and every computer in these networks exchange information according to certain rules called protocols. These different computers and different networks are united with the common thread of two protocols, i.e., Internet Protocol (IP), and Transmission Control Protocol (TCP).

Communication is one of the most popular use of Internet. The internet provides a capability so powerful that it can be used for almost any purpose that depends on information. It is accessible by every individual who connects to one of it’s constitute networks. It supports human communication via electronic mail (E-Mail), Chat Rooms, Newsgroups, and Audio and Video transmission. It allows people to work collaboratively at many different locations. It supports access to digital information by many applications, including the World Wide Web (WWW). The internet has proved to be spawning grounds for a large and growing number of “e-businesses” that carry out most of their sales and services over the internet. Many experts believe that the internet will dramatically transform business as well as society.

What is Computer?

 A computer is an electronic device that can perform a variety of operations according to a set of instructions called program. It then displays or prints the result. A computer is a general purpose machine that manipulates raw facts according to a set of instruction that

are fed into it.

what is computer?

 The word “Computer” comes from the word compute which means to calculate. So a computer is normally considered to be a calculating device that performs arithmetic operations at an enormous speed. But more accurately, a computer may be defined as a device that operates upon data.

 The two basic types of computer are the following:

a)      Analog

b)      Digital

Analog Computer

 Analog computer handles or process information which is of a physical nature, for example temperature, pressure, etc. These are based on the measuring of analog or equivalent physical value.

Digital Computer

 Digital computers process information which is essentially in a binary or two-state from, namely zero and one. When talking about computer, we mostly refer to the digital type of electronic machines.

 Digital computers fall into ranges called microcomputers, Minicomputers, mainframes and supercomputer, classified in ascending order of size-small, medium, large and very large.

Handheld or Mobile Computing Devices

 Handheld or mobile computing devices are small, compact and portable devices used typically by those people who work in a mobile environment, such as delivery services, utility companies, salesmen, traveling businessmen, etc. It allows people to effectively communicate and interact with the fixed organizational information system, wherever they themselves may be located.

 The following are some of the mobile computing devices:

a)      Laptops and Notebooks

b)      PDAs (Personal Digital Assistants)

c)      Tablet Personal Computer (PC)

Laptops and Notebooks

 A laptop PC is a small, compact and portable machine which runs on battery power. You can unfold it and work with it on your lap and hence the name is given to it. It can be carried in your suitcase easily.

Laptop

 A Notebook is a smaller and lighter version of the laptop model.

PDAs (Personal digital assistants)

 Personal Digital Assistants (PDA) is a handheld computer and popularly known as Palmtop. It has a touch screen and a memory card for storage of data.

PDAs Device

Tablet PC

 A tablet PC or simply tablet, is a medium-size mobile computer integrated into a flat touch screen and primarily using stylus, digital pen or fingertip input along with a virtual onscreen keyboard in lieu of a physical keyboard. It is a touch-pad device that features and qualities of a smart phone and a laptop.

Tablet PC