Computer basics
Today’s world is an information-rich world and it has become a necessity for everyone to know about computers. Purpose of this tutorial is to introduce you about computer and its fundamentals.
Functionalities of a computer
Any digital computer carries out five functions in gross terms:
Takes data as input.
Stores the data/instructions in its memory and use them when required.
Processes the data and converts it into useful information.
Generates the output
Controls all the above four steps.
Definition
Computer is an electronic data processing device which accepts and stores data input, processes the data input, and generates the output in a required format.
Advantages
Following list demonstrates the advantages of computers in today's arena.
High Speed
Computer is a very fast device.
It is capable of performing calculation of very large amount of data.
The computer has units of speed in microsecond, nanosecond, and even the picosecond.
It can perform millions of calculations in a few seconds as compared to man who will spend many months for doing the same task.
Accuracy
In addition to being very fast, computers are very accurate.
The calculations are 100% error free.
Computers perform all jobs with 100% accuracy provided that correct input has been given.
Storage Capability
Memory is a very important characteristic of computers.
A computer has much more storage capacity than human beings.
It can store large amount of data.
It can store any type of data such as images, videos, text, audio and many others.
Diligence
Unlike human beings, a computer is free from monotony, tiredness and lack of concentration.
It can work continuously without any error and boredom.
It can do repeated work with same speed and accuracy.
Versatility
A computer is a very versatile machine.
A computer is very flexible in performing the jobs to be done.
This machine can be used to solve the problems related to various fields.
At one instance, it may be solving a complex scientific problem and the very next moment it may be playing a card game.
Reliability
A computer is a reliable machine.
Modern electronic components have long lives.
Computers are designed to make maintenance easy.
Automation
Computer is an automatic machine.
Automation means ability to perform the given task automatically.
Once a program is given to computer i.e., stored in computer memory, the program and instruction can control the program execution without human interaction.
Reduction in Paper Work
The use of computers for data processing in an organization leads to reduction in paper work and results in speeding up a process.
As data in electronic files can be retrieved as and when required, the problem of maintenance of large number of paper files gets reduced.
Reduction in Cost
Though the initial investment for installing a computer is high but it substantially reduces the cost of each of its transaction.
Disadvantages
Following list demonstrates the disadvantages of computers in today's arena
No I.Q
A computer is a machine that has no intelligence to perform any task.
Each instruction has to be given to computer.
A computer cannot take any decision on its own.
Dependency
It functions as per a user’s instruction, so it is fully dependent on human being
Environment the operating environment of computer should be dust free and suitable.
No Feeling
Computers have no feelings or emotions.
It cannot make judgement based on feeling, taste, experience, and knowledge unlike a human being.
A
Brief History of the Computer
Computers and computer applications are on almost every aspect of our daily lives. As like many ordinary objects around us, we may need clearer understanding of what they are. You may ask "What is a computer?" or "What is a software", or "What is a programming language?" First, let's examine the history.
1. The history of computers starts out about 2000 years ago in Babylonia (Mesopotamia), at the birth of the abacus, a wooden rack holding two horizontal wires with beads strung on them.
2. Blaise Pascal is usually credited for building the first digital computer in 1642. It added
numbers entered with dials and was made to help his father, a tax collector.
The basic principle of his calculator is still used today in water meters and modern-day odometers. Instead of having a carriage wheel turn the gear, he made each ten-teeth wheel accessible to be turned directly by a person's hand (later inventors added keys and a crank), with the result that when the wheels were turned in the proper sequences, a series of numbers was entered and a cumulative sum was obtained. The gear train supplied a mechanical answer equal to the answer that is obtained by using arithmetic.
This first mechanical calculator, called the Pascaline, had several disadvantages. Although it did offer a substantial improvement over manual calculations, only Pascal himself could repair the device and it cost more than the people it replaced! In addition, the first signs of technophobia emerged with mathematicians fearing the loss of their jobs due to progress.
3. A step towards automated computing was the development of punched cards, which were first successfully used with computers in 1890 by Herman Hollerith and James Powers, who worked for the US. Census Bureau. They developed devices that could read the information that had been punched into the cards automatically, without human help. Because of this, reading errors were reduced dramatically, work flow increased, and, most importantly, stacks of punched cards could be used as easily accessible memory of almost unlimited size. Furthermore, different problems could be stored on different stacks of cards and accessed when needed.
4. These advantages were seen by commercial companies and soon led to the development of improved punch-card using computers created by International Business Machines (IBM), Remington (yes, the same people that make shavers), Burroughs, and other corporations. These computers used electromechanical devices in which electrical power provided mechanical motion -- like turning the wheels of an adding machine. Such systems included features to:
- feed in a specified number of
cards automatically
- add, multiply, and sort
- feed out cards with punched
results
5. The start of World War II produced a large need for computer capacity, especially for the military. New weapons were made for which trajectory tables and other essential data were needed. In 1942, John P. Eckert, John W. Mauchly, and their associates at the Moore school of Electrical Engineering of University of Pennsylvania decided to build a high - speed electronic computer to do the job. This machine became known as ENIAC (Electrical Numerical Integrator And Calculator)
6. The size of ENIAC’s numerical "word" was 10 decimal digits, and it could multiply two of these numbers at a rate of 300 per second, by finding the value of each product from a multiplication table stored in its memory. ENIAC was therefore about 1,000 times faster then the previous generation of relay computers. ENIAC used 18,000 vacuum tubes, about 1,800 square feet of floor space, and consumed about 180,000 watts of electrical power. It had punched card I/O, 1 multiplier, 1 divider/square rooter, and 20 adders using decimal ring counters, which served as adders and also as quick-access (.0002 seconds) read-write register storage. The executable instructions making up a program were embodied in the separate "units" of ENIAC, which were plugged together to form a "route" for the flow of information.
7. Early in the 50’s two important engineering discoveries changed the image of the electronic - computer field, from one of fast but unreliable hardware to an image of relatively high reliability and even more capability. These discoveries were the magnetic core memory and the Transistor - Circuit Element.
These technical discoveries quickly found their way into new models of digital computers. RAM capacities increased from 8,000 to 64,000 words in commercially available machines by the 1960’s, with access times of 2 to 3 MS (Milliseconds). These machines were very expensive to purchase or even to rent and were particularly expensive to operate because of the cost of expanding programming. Such computers were mostly found in large computer centers operated by industry, government, and private laboratories - staffed with many programmers and support personnel. This situation led to modes of operation enabling the sharing of the high potential available.
8. Many companies, such as Apple Computer and Radio Shack, introduced very successful PC’s in the 1970's, encouraged in part by a fad in computer (video) games. In the 1980's some friction occurred in the crowded PC field, with Apple and IBM keeping strong. In the manufacturing of semiconductor chips, the Intel and Motorola Corporations were very competitive into the 1980s, although Japanese firms were making strong economic advances, especially in the area of memory chips. By the late 1980s, some personal computers were run by microprocessors that, handling 32 bits of data at a time, could process about 4,000,000 instructions per second.
Types of computer
Since the advent of the first computer different types and sizes of computers are offering different services. Computers can be as big as occupying a large building and as small as a laptop or a micro-controller in .mobile & embedded systems.
The four basic types of computers are as under:
Supercomputer
Mainframe Computer
Minicomputer
Microcomputer
Supercomputer
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
Exascale Supercomputer
On 29th July, 2015, President of the United States, Barack Obama, approved the development of an Exascale Super Computer. The Exascale Super computer will be 30 times faster and more powerful than today’s fastest Super Computers. The need to develop such a high performance Supercomputer comes after China’s surge in high performance computing. However, the US still tops the list of Supercomputers with 233 high performance machines. China has 37 Supercomputers but they lead the list of the most powerful and high performance supercomputers since June 2013.
Space Exploration
Supercomputers are used to study the origin of the universe, the dark-matters. For these studies scientist use IBM’s powerful supercomputer “Roadrunner” at National Laboratory Los Alamos.
Earthquake studies
Supercomputers are used to study the Earthquakes phenomenon. Besides that supercomputers are used for natural resources exploration, like natural gas, petroleum, coal, etc.
Weather Forecasting
Supercomputers are used for weather forecasting, and to study the nature and extent of Hurricanes, Rainfalls, windstorms, etc.
Nuclear weapons testing
Supercomputers are used to run weapon simulation that can test the Range, accuracy & impact of Nuclear weapons.
Popular Supercomputers
- IBM’s Sequoia, in United States
- Fujitsu’s K Computer in Japan
- IBM’s Mira in United States
- IBM’s SuperMUC in Germany
- NUDT Tianhe-1A in China
Mainframe computer
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
Minicomputer
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
Microcomputer
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.
Desktop computers, Gaming consoles, Sound & Navigation system of a car, Netbooks, Notebooks, PDA’s, Tablet PC’s, Smartphones, Calculators are all type of Microcomputers.
Hardware parts of computer
INTRODUCTION TO COMPUTER HARDWARE
A Computer system can be broadly classified in to four parts namely:
- Input hardware
- Processing hardware
- Storage hardware
- Output hardware
A computer is only useful when it is able to communicate with the external environment. When you
work with the computer you feed your data and instructions through some devices to the computer.
These devices are called Input devices. Similarly computer after processing, gives output through
other devices called output devices.
For a particular application one form of device is more desirable compared to others. We will
discuss various types of I/O devices that are used for different types of applications. They are also
known as peripheral devices because they surround the CPU and make a communication between
computer and the outer world.
A) INPUT DEVICES
Input devices are necessary to convert our information or data in to a form which can be understood by the computer. A good input device should provide timely, accurate and useful data to the main memory of the computer for processing followings are the most useful input devices. Some of examples of input devices are like keyboard, scanner, mouse, web cam, etc
B) OUTPUT DEVICES
An output device is any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. For example, the image shows an inkjet printer, an output device that can make a hard copyof any information shown on your monitor. Another example of an output device is a computer monitor, which displays an image that is received from the computer. Monitors and printers are two of the most common output devices used with a computer. Examples of output devices are like monitor, speaker, printer, etc.
C) PROCESSING DEVICES
When a computer receives data from an input device, the data must go through an intermediate stage before it can be sent to an output device, like a monitor, printer, or speakers. A processing device is any device in a computer that handles this intermediate stage, being responsible for controlling the storage and retrieval of data.
Some of the most common processing devices in a computer include the following:
- central processing unit (CPU)
- graphics processing unit (GPU)
- motherboard
- network card
- sound card
D) STORAGE DEVICES
Alternatively referred to as digital storage, storage, storage media, or storage medium, a storage device is any hardware capable of holding information either temporarily or permanently. The picture shows an example of a Drobo, an external secondary storage device.
There are two types of storage devices used with computers: a primary storage device, such as RAM, and a secondary storage device, like a hard drive. Secondary storage can be removable,internal, or external storage.
Examples of computer storage
- Floppy diskette
- Hard drive
- Magnetic strip
- Tape cassette
- Zip diskette
- Jump drive or flash drive
- Memory card
- Memory stick
- SSD
Software parts of computer
Sometimes abbreviated as SW and S/W, software is a collection of instructions that enable the user to interact with a computer, its hardware, or perform tasks. Without software, computers would be useless. For example, without your Internet browser, you could not surf the Internet or read this page and without an operating system, the browser could not run on your computer. Microsoft Excel is an example of a spreadsheet software program.
Examples and types of software
Below is a list of the different kinds of software a computer may have installed with examples of related programs. Click any of the links below for additional information.
It should be noted that although software is thought of as a program, it can be anything that runs on a computer. The table below also includes a program column to clarify any software that is not a program.
The following are the two main types of computer software:
System software
Is software on a computer that is designed to control and work with computer hardware. The two main types of system software are the operating system and the software installed with the operating system, often called utility software. The operating system and utility software typically depend on each other to function properly.
Some system software is used directly by users and other system software works in the background. System software can allow users to interact directly with hardware functionality, like the Device Manager and many of the utilities found in the Control Panel.
Software that allows users to create documents (e.g. Microsoft Word), edit pictures (e.g.Adobe Photoshop), browse the Internet (e.g. Microsoft Internet Explorer), or check their e-mail (e.g. Microsoft Outlook) are considered application software. System software does not involve direct interaction with computer hardware or operating system functionality, but may require the use of one or more hardware components to function properly. Some of computer system software are windows 7, windows 8.1, Linux etc
Application 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. When you begin creating a document, the word processing software has already set the margins, font style and size, and the line spacing for you. But you can change these settings, and you have many more formatting options available. For example, the word processor application makes it easy to add color, headings, and pictures or delete, copy, move, and change the document's appearance to suit your needs.
Microsoft Word is a popular word-processing application that is included in the software suite of applications called Microsoft Office. A software suite is a group of software applications with related functionality. For example, office software suites might include word processing, spreadsheet, database, presentation, and email applications. Graphics suites such as Adobe Creative Suite include applications for creating and editing images, while Sony Audio Master Suite is used for audio production.
