S R Computer Institute

CCC (PART-1)

Computer:

Computer is an electronic device that is designed to work with Information. The term computer is derived from the Latin term ‘compute’, this means to calculate or programmable machine. Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations. Computer cannot do anything without a Program. It represents the decimal numbers through a string of binary digits.
Charles Babbage is called the “Grand Father” of the computer. The First mechanical computer designed by Charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards.

Functions of Computer:

Input (Data):

Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc.

Store:

Saving data and instructions so that they are available for processing as and when required.

Process:

Process is the operation of data as per given instruction. It is totally internal process of the computer system.

Output:

Output is the processed data given by computer after data processing. Output is also called as Result. We can save these results in the storage devices for the future use.

Computer Classification: By Size and Power

Computers differ based on their data processing abilities. They are classified according to purpose, data handling and functionality.

According to functionality, computers are classified as:

1) Analog Computer:

A computer that represents numbers by some continuously variable physical quantity. Such type of data includes temperature, pressure, speed weight, voltage, depth etc. These quantities are continuous and having an infinite variety of values. Analog computers are the first computers being developed and provided the basis for the development of the modern digital computers.

2) Digital Computers:

A Digital Computer, as its name implies, works with digits to represent numerals, letters or other special symbols. Digital Computers operate on inputs which are ON-OFF type and its output is also in the form of ON-OFF signal. Normally, an ON is represented by a 1 and an OFF is represented by a 0. So we can say that digital computers process information which is based on the presence or the absence of an electrical charge or we prefer to say a binary 1 or 0.

Types of Digital Computer:

The four basic types of computers are as under:

1. Supercomputer
2. Mainframe Computer
3. Minicomputer
4. Microcomputer

Micro computer:

In which the various integrated circuits and elements of a computer are replaced by single integrated circuit called a “chip”.

Desktop computers, laptops, personal digital assistant (PDA), tablets & smartphones are all types of microcomputers. The micro-computers are widely used & the fastest growing computers. These computers are the cheapest among the other three types of computers. The Micro-computers are specially designed for general usage like entertainment, education and work purposes. Well known manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba. Example: Laptop, Desktop, notebook, palmtop etc.

Mini computers:

Physically small computers compared with mainframes. Minicomputers are used by small businesses & firms. Minicomputers are also called as “Midrange Computers”. These are small machines and can be accommodated on a disk with not as processing and data storage capabilities as super-computers & Mainframes. These computers are not designed for a single user. Individual departments of a large company or organizations use Mini-computers for specific purposes. For example, a production department can use Mini-computers for monitoring certain production process.

Popular Minicomputers:

• K-202
• Texas Instrument TI-990
• SDS-92
• IBM Midrange computers

Mainframes computers:

Although Mainframes are not as powerful as supercomputers, but certainly they are quite expensive nonetheless, and many large firms & government organizations uses Mainframes to run their business operations. The Mainframe computers can be accommodated in large air-conditioned rooms because of its size. Super-computers are the fastest computers with large data storage capacity, Mainframes can also process & store large amount of data. Banks educational institutions & insurance companies use mainframe computers to store data about their customers, students & insurance policy holders.

Popular Mainframe computers

• Fujitsu’s ICL VME
• Hitachi’s Z800

Large general purpose computes with extensive processing, storage and input/ output capabilities. The market for these computers is dominated by IBM.

Super computers:

The most powerful computers in terms of performance and data processing are the Supercomputers. These are specialized and task specific computers used by large organizations. These computers are used for research and exploration purposes, like NASA uses supercomputers for launching space shuttles, controlling them and for space exploration purpose. CRAY-1 is the first super computer. India’s First Super computer is PARAM-10000.

Note:

1. CRAY-1 is the first super computer.
2. India’s first super computer is PARAM-10000
3. First manufactured computer in India is Sidhartha.
4. First calculation Devise is Abacus.

“Seymour Cray designed the first Supercomputer “CDC 6600” in 1964. CDC 6600 is known as the first ever Supercomputer.”

A large and very powerful mainframe computer is called a supercomputer. Such supercomputers are applied to the solution of very complex and sophisticated scientific problem and for national security purposes of some advance nations.

“Presently, China’s “Tianhe – 2” is the world’s faster Supercomputer.”

The Tianhe – 2 can perform 100 Petaflops , i.e quadrillions of floating point operations per second.

Basic characteristics about computer are:

1. Speed: – As you know computer can work very fast. It takes only few seconds for calculations that we take hours to complete. You will be surprised to know that computer can perform millions (1,000,000) of instructions and even more per second. Therefore, we determine the speed of computer in terms of microsecond (10-6 part of a second) or nanosecond (10 to the power -9 part of a second). From this you can imagine how fast your computer performs work.

2. Accuracy: – The degree of accuracy of computer is very high and every calculation is performed with the same accuracy. The errors in computer are due to human and inaccurate data.

3. Diligence: – A computer is free from tiredness, lack of concentration, fatigue, etc. It can work for hours without creating any error. If millions of calculations are to be performed, a computer will perform every calculation with the same accuracy. Due to this capability it overpowers human being in routine type of work.

4. Versatility: – It means the capacity to perform completely different type of work. You may use your computer to prepare payroll slips. Next moment you may use it for inventory management or to prepare electric bills.

5. Power of Remembering: – Computer has the power of storing any amount of information or data. Any information can be stored and recalled as long as you require it, for any numbers of years. It depends entirely upon you how much data you want to store in a computer and when to lose or retrieve these data.

6. No IQ: – Computer is a dumb machine and it cannot do any work without instruction from the user. It performs the instructions at tremendous speed and with accuracy. It is you to decide what you want to do and in what sequence. So a computer cannot take its own decision as you can.

7. No Feeling: – It does not have feelings or emotion, taste, knowledge and experience. Thus it does not get tired even after long hours of work. It does not distinguish between users.

8. Storage: – The Computer has an in-built memory where it can store a large amount of data. You can also store data in secondary storage devices such as floppies, which can be kept outside your computer and can be carried to other computers.

Generations of computer:

Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. Nowadays, generation includes both hardware and software, which together make up an entire computer system.

Computer-First Generation (1945 to 1955):

The period of first generation was from 1945-1955. The computers of first generation used vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes, like electric bulbs, produced a lot of heat and the installations used to fuse frequently. Therefore, they were very expensive and only large organizations were able to afford it.

In this generation, mainly batch processing operating system was used. Punch cards, paper tape, and magnetic tape was used as input and output devices. The computers in this generation used machine code as the programming language.

Computer – Second Generation( 1955 to 1964):

The period of second generation was from 1955-1964. In this generation, transistors were used that were cheaper, consumed less power, more compact in size, more reliable and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as the primary memory and magnetic tape and magnetic disks as secondary storage devices.

In this generation, assembly language and high-level programming languages like FORTRAN, COBOL were used. The computers used batch processing and multiprogramming operating system.

Computer – Third Generation (1964 to 1974)

The period of third generation was from 1964-1974. The computers of third generation used Integrated Circuits (ICs) in place of transistors. A single IC has many transistors, resistors, and capacitors along with the associated circuitry.

The IC was invented by Jack Kilby. This development made computers smaller in size, reliable, and efficient. In this generation remote processing, time-sharing, multiprogramming operating system were used. High-level languages (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used during this generation.

Computer – Fourth Generation (1974 to 1989)

The period of fourth generation was from 1974-1989. Computers of fourth generation used Very Large Scale Integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements with their associated circuits on a single chip made it possible to have microcomputers of fourth generation.

Fourth generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to Personal Computer (PC) revolution. In this generation, time sharing, real time networks, distributed operating system were used. All the high-level languages like C, C++, DBASE etc., were used in this generation.

Computer – Fifth Generation (1989 to till date)

The period of fifth generation is 1989-till date. In the fifth generation, VLSI technology became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components.

This generation is based on parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch in computer science, which interprets the means and method of making computers think like human beings. All the high-level languages like C and C++, Java, .Net etc., are used in this generation.

Software:

The term ‘software‘ refers to the set of electronic program instructions or data a computer processor reads in order to perform a task or operation. In contrast, the term ‘hardware‘ refers to the physical components that you can see and touch, such as the computer hard drive, mouse, and keyboard.

Software can be categorized according to what it is designed to accomplish. There are two main types of software:

1. System Software
2. Application Software

Systems Software

Systems software includes the programs that are dedicated to managing the computer itself, such as the operating system, file management utilities, and disk operating system (or DOS). The operating system manages the computer hardware resources in addition to applications and data. Without systems software installed in our computers we would have to type the instructions for everything we wanted the computer to do!

Ex: Operating system(windows 7,8,10, vista, NT,XP), language translator (compiler, interpreter, assembler, linker, loader) etc.

Compiler:

1. A computer program which reads source code and outputs assembly code or executable code is called compiler.
2. A program that translates software written in source code into instructions that a computer can understand Software used to translate the text that a programmer writes into a format the CPU can use.
3. A piece of software that takes third-generation language code and translates it into a specific assembly code. Compilers can be quite complicated pieces of software.

Interpreter:

1. Interpreter Takes Single instruction as input .No Intermediate Object Code is Generated Conditional Control Statements are Executes slower Memory Requirement is Less Every time higher level program is converted into lower level program Errors are displayed for every instruction interpreted (if any)The interpreter can immediately execute high-level programs, thus interpreters are sometimes used during the development of a program, when a programmer wants to add small sections at a time and test them quickly.
   1. In addition, interpreters are often used in education because they allow students to program interactively.

Applications Software:

Application software, or simply applications, are often called productivity programs or end-user programs because they enable the user to complete tasks, such as creating documents, spreadsheets, databases and publications, doing online research, sending email, designing graphics, running businesses, and even playing games! Application software is specific to the task it is designed for and can be as simple as a calculator application or as complex as a word processing application.

Ex. Tally, Coral draw , Photoshop,  Mircosoft Office.

Electronic Data Processing(EDP):

After collecting data, it is processed to convert into information. The data is processed again and again until accurate result is achieved. This is called data processing cycle.
Data processing cycle involves following three basic activities:

1. Input

2. Processing

3. Output

Applications of IECT

IECT or Information, Electronics and Communication Technology is used in various sectors.Electronic governance or e-governance is the application of information electronics and communication technology (ICT) for delivering government services to common people directly. IECT is very common and used by most of people now a days like Internet, Cell phones, radios, television and satellite etc. are medium of communication and all it works electronically. The term communication is used to make contact or sending and receiving messages from other people, institution or government

e-governance:

e Governance is one of the applications of IECT. With the help of e Governance various Government Services can be delivered to people, Information can be transmitted. Network of several stand alone systems can be created or any system can be added as a member of this group. Here transmission of information can be taken place between Government and Citizen also Government and Business. Also all the transactions taken place in back office and in entire network are available to process simultaneously.

Multimedia and Entertainment:

Now a day, people use multimedia in various sectors like business, education, research, entertainment etc. Therefore we can define multimedia as follows – it is an interface used to present information in various formats like characters, numbers, symbols, audio, video, graphic and animation.

Difference Between e-Government and e-Governance:

E-Government implies the implementation of information and communication technology like internet, to improve government activities and process, with the aim of increasing efficiency, transparency, and citizen involvement. On the other hand, e-Governance means governing or administering a country/state or organization, with the help of information and communication technology.

Activities of E-Government using E-governance:

• G2G (Government to Government): The exchange of information between government agencies or departments, i.e. within the confines of government is called as G2G interaction.
• G2C (Government to Citizen): As the name suggests, it is the interaction between government and the citizens of the country. It involves establishing an interface, to enable the general public to access information and services, whenever and wherever they want. They can also give their feedback with respect to policies and rules.
• G2B (Government to Business): The dissemination of information between government and the business, is G2B interaction. It focuses on reducing red-tapism, establishing transparency and accountability in the business environment.
• G2E (Government to Employees): The interaction between government and employees to increase employee morale and satisfaction, is made easier and faster with the help of information and communication technology.