Operating System and itsFundamental

Operating system is the software part of computer setup which is used to manage and maintain the connection between software and hardware part your computer. There is lot of operating system used for computer. Here in this blog some fundamentals of operating system are describes below:

Access Control:
When you start a computer it runs in supervisor mode. Operating system has capability of placing the computer system in protected mode.

 Programs Execution:
The execution of any program wants from operating system to create a processes.  Process is created by operating system kernel by installing the program code from the disk.

File Management:
Operating systems have command over the application program to access the files stored on disk. The operating system like Unix and Linux implements  a file system virtually to get the access of different file system.

Error Message "No Bootable Device" What To Do???

Once on a pleasant morning you wish to listen music on your laptop, but what’s this shit going on as you wish to open it you got an error message displaying ‘No Bootable Device Found’. You tried all your effort but failed as you are not a geek of computer and its related term. Friends to help you in such an awkward situation I have written this blog for you. It will be helpful for you and will provide you the best possible solution.

'No Bootable Device' - What Does It Mean and Solution To Fix It?

BIOS (The Basic Input Output System) which is an inbuilt software in your computer and independent of the operating system, which loads or 'boots' it into operation. The message 'No Bootable device' is displayed by BIOS on your computer system when it cannot find an operating system to load from any storage medium on the PC.

The actual loading of the operating system is "Booting", executed by BIOS. Like a floppy disk, hard drive, CD, DVD, 'Boot Device' is also a storage medium, which carry the installed operating system files. If that device is not located the above mentioned error message is displayed on your screen.

Here are three of the possible causes, that may lead to this kind of an error.

Corruption Of Operating System File:

Crashing of installed operating system on your system's hard drive is the main cause of not detection of booting device by BIOS.  This kind of problem happens because of virus attack Due to a virus attack your operating system's existing working installation may get corrupted. That's the reason, on startup, the operating system can not be detected by BIOS and you computer's screen displays the message "No Bootable Device Found".

Solution:

The only way to solve this problem is to load the disk recovery or CD of your operating system in your computer's optical drive and run a complete reinstallation. Use best antivirus software to save your computer system from virus attack. If you already have an antivirus then update it regularly to make your computer virus free.

Hard Drive Disconnected:

Many time it happens that your hard drive is disconnected from motherboard.In this case BIOS is unable to detect the hard drive as a bootable device. To check this type of problem, enter BIOS setup by pressing the appropriate key (F1, F2 or any other) during startup.

Solution:

To solve this problem, you have to check the connection of hard drive to motherboard. To check it you have to open up your computer's cabinet. If the connecting cable from the motherboard has disconnected from the hard drive then restoring the connection should solve your problem. In case of laptop you have to do the same as desktop computer.

Hard Drive Crash:

Crashing of this hard drive also the reason behind display on error message problem. It may be happen because of actual physical damage of the hard drive or creation of bad sectors. Since the hard drive is damaged, it may not be detected by BIOS, leading to a booting problem.

Solution:

To solve this problem you have to replace the hard drive of your computer.

After following the steps describe above you may able to solve this error message displaying problem of your computer.If still your computer suffers from this kind of problem you need to ask computer technician or go for computer repair.

DISPLAY TECHNOLOGIES

In the past we have only C.R.T as a display technology but with the inventions of LCD and OLED the monopoly of C.R.T has been vanished and now it is only used as refernce for maintaing standards.In this article we will go from the LCD to latest display technologies and I will let you know your mobile display technologies.

LCD DISPLAY :

LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.

Their are two types of LCD:

LCD Applicatios: mobile,Monitor,Television

1. T.F.T: With Thin Film Transistor (TFT) LCDs, each pixel is controlled by one to four transistors. Typically one transistor is used for each of the RGB colour channels.

• Wider viewing angle range.
• Provides more accurate color control.

2. S.T.N:

Super Twisted Nematic(STN) LCDs, Pixels are controlled by energising the appropriate row and column drive lines of the matrix from outside the display, resulting in a slow frame rate.

• Use passive matrix technology.

• Limited viewing angle.

APPLICATIONS: used in mobiles,monitor screen,laptop,televison

PROS of LCD:

 Require Less Power : LCD consumes less power as compare to the CRT .

Smaller and weigh Less : They are light in weight and comes in different sizes tus giving customer wide range of products.

Adjustable : They are not bulky in size and can be adjusted according to the users requirement .You can tilt , adjust height from horizontal to vertical.

Less Eye strain : LCD displays each pixel off individually, so LCD Displays don't have flickering problems and offer customer a soothing experience.

CONS of LCD:

Less viewing angle range.

Less responsive time.

Fragile in nature.

List of Mobiles using LCD Screen:

HTC Sensation XELG, Optimus 3D, LG Optimus Black.

PLASMA:

The central element which is reponsible for emitting light in tihs technology is Plasma which is a gas made up of free flowing ions and and electrons.When electric voltage is applied across the positively charged ion moves towards negative electrode and negatively charged ion moves towards positive electrode during this they strike with other particle and this will results in emission of photons and you get desired image on your screen.

You can understand the working by the following diagram:

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PROS of Plasma technology:

Wider viewing angles means you can view monitor from any viewing angle it is not necessary to sit in front of it

High contrast ratio.

Preproduction of colours through pixels is excellent.

CONS of Plasma technology:

Prone to screen burn-in problem.

Have short lifespan.

Plasma screen are Heavier than LCD screen.

APPLICATIONS: used in television,mobiles,monitors.

OLED:

Organic Light Emitting Diode

OLED technology was invented by Eastman Kodak in the early 1980s.In this technology an organic polymer is used .The organic polymer used is made of carbon.This organic semiconductor material is situated between the electrodes. When electric current is passed emission of light occurs.

Features of OLED:

• Wider viewing angle.

• Fast response rate and brighter colour display.

 

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Computer & Computer Based Technologies

 Introduction:

Computer the most important discovery by man which has made miracle and has changed the life of human .There is nothing in the world which can't be done by computers.With the advancement in technology computer is become user friendly and is become a very important part of every age group.

        

      Computer is an electronic machine which can take data from user through input device, process it and gives output through otuput devices. Computer can perform the most difficult task in seconds which will take long time if performed by man.

Characterstics of Computer :   

• Versatility : computer can be used for multitasking that means at one time we can perform many tasks.

• Deligent : it does not get tired even after working many days

• Large storage capacity : can store large amount of data in its memory.

• Intelligent : can perform large number of calculation is seconds.even a pc can execute millions of instrucion in one sec.

• long life: computer has long life and it depends on power supply.              

Evolution of computer :                            

Computer is made by man not in single effort it is a long journey of hardwork,dedication and devotion.in the early days of ninteenth century people we have some machines like abacus which can perform some arithmatic calculations.CHARLES BABBAGE the father of computer is the person one who came with the idea of using shaft and mechanical engine for data management in the computer.The first computer can do only arithmatic.Blaise Pascal,Leibnitz have done modification and improved the speed .

Genrations of Computer:                                     

1st generation of computer:

1st generations compter makes use of vaccum tubes.They are very big in size,consumes lot of eenergy,produces excess of heat and difficult to maintain. ENIAC was used to perform simple arithmatic calculations.

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2nd generations of computer:

with the discovery of transistors the size of computer reduces and EDSAC was built by william hackert & Mauchy and it is used for scientific calculations.But problem of powers dissapation remain s the matter of concern for the scientist.

3rd generation of computer:

In this generation of computer MOSFET are used which reduces size and heat dissipation .Mainframe computer and Super computers are devloped which are used for military and scientific purposes

4th generation of computer:

The 4th generation of computer is the present generation of computer in which scientist are devloping computers/computer based system by using artificial intelligence and parallel computing.

Application of computer : Now days computer is used in every field like education,medical , industrial, defence,research purposes.

Now days we have computers with i-seies processor which have internal architecture based on 64 bit word length,provide enhanced speed, support many i/o external devices.It comes in three version i3,i5,i7.The cache memory of these processor is more as compare to previous intel's processor . Window 7 operating system is currently used with these processor in order to get fast internet access and with the evolution 3g,4g technology it becomes possible to transfer data at 2-8 mbps. In 3g and 4g  WCDMA & IMT 2000 techniques is used which is intended to provide video , data transmission at faster rate.With the use of these technology it is possible to form adhoc network i.e. temperary network between devices to transfer data.

Bluetooth:

In computers bluetooth technology is uesd to form temperary cionnection between devices(mobiles,computer).The range of bluetooth is 10-15 meters.the IEEE 802.11 protocal as used in bluetooth .It uses frequency band of 2-4 ghz IMS band.Now we have "Bluetooth 2.0" 

NFC: 

The NFC(Near field communication) is a wireless communication technology use to communicate point to point.The NFC is devloped for mobiles.It is used to transfer data and secure bills payment.

In future we will have Wimax by which we can transfer data miles away.It uses IEEE 802.15 protocal.

                                                NFC   -)      BLUETOOTH  -)   WIMAX

The technology can be used to transfering data just by touch use wrist computers with biometric sensors .Now days we have system combination of machines with human i.e humanoids.

The embedded systems are also used for perfoming task automatically .They play a major part in robotics and automation industry.the automation in industries has made a significant change productivity of manufacturing goods as well in the profit of companies.

You can check out this video and it will help u to go beyond the bluetooth and take step ahead of others to enjoy this new technology.