Tuesday, June 28, 2011

Internet technology of Storage organization


Unlike magnetic disks, which have several concentric tracks, an optical disk has one long   track, which starts at the outer edge and spirals inward to the center (see figure). This spiral track is ideal for reading large blocks of sequential data, such as music. However, it makes for slower random access time than the concentric tracks used by  magnetic disks, whose sectors can be located faster because they are always found on a given track at a fixed distance from the center.
              Like a track on a magnetic disk, the track of an optical disk is split up into sectors but with optical disks, each sector has the same length, regardless of whether it is located near the disks center or away from the center. This type of data organization allows data to be packed at maximum density over the entire disk. However, it also requires a more complicated drive mechanism because the rotation speed of the disk must vary inversely with the radium, the drive must slow down the disks rotation speed to read sectors towards the outside of the disk and speed it up to read sectors towards the center of the disk.
The cost-per –bit of storage is very low for optical disk because of their low cost and enormous storage density. They come in various sizes, ranging from 12-inch to 4.7 inch In diameter. The most popular is of 5.25 inch diameter whose capacity is around 650 megabytes. This storage capacity is equivalent to about 250000 pages of printed text or total capacity of 550 double sided, high-density floppy of the same size. This tremendous storage capacity makes optical disks the most suitable storage media for multimedia application. As optical disk have a single track, their storage capacity is multiple of the number of sectors and number of bytes per sector.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

Internet technology of Winchester disks


A Winchester disk also consists of multiple (two or more)hard disk platters mounted on a single central shaft. However, the main difference between a Winchester disk and a disk pack is that Winchester disks are of fixed type. That is, the hard disk platters and the disk drive are sealed together in a contamination free container  and cannot be separated from each other. Hence as opposed to disk packs, which have virtually unlimited capacity, Winchester disks have limited capacity. However, for the same number of disk platter of the same size, Winchester disks can manage to have larger storage capacity than disk packs due to the following reasons.
       Because both the disk platters and the disk drive are sealed in a contamination free container and do not require to be separated later, all the surfaces of all the disk platter(including the upper surface of the topmost platter and the lower surface of the bottommost platter) are used for data recording in case of Winchester disks. That is for a Winchester disk with four platters, there are eight surfaces on which data can be recorded as opposed to six surfaces in case of a disk pack with four platters.
              The contamination-free environment allows Winchester disks to employ much greater precision of data recording and accessing resulting in greater density of data storage than the interchangeable disk packs.
          The storage capacity of today Winchester disks is usually of the order of a few tens of megabytes to a few gigabytes (10 bytes).          

Sunday, June 26, 2011

Internet of access mechanism


Data are recorded on the tracks of a spinning disk surface and read from the surface by one or more read write heads. As shown in figure 6.4 the read write heads are mounted on an access arms assembly. Most disk drives have a single read write head for each disk surface. However some faster disk systems use multiple heads on each access arm to read a number of adjacent tracks simultaneously.
     The access arms assembly can be moved in and out In the direction shown in the figure 6.4 so that the read write head can be moved horizontally across the surface of the disk. In this manner the read write heads can be positioned on any track on which data are to be recorded or from which data are to be read.
The read write heads are of flying type. That is they do not have direct contact with the disk surface. This prevents wear on the surface of the disk. A separation of about 0.00002 inch is maintained between a read write head and its corresponding disk surface. In fact read write heads fly so close to the disk surface that , if a dust particle(typically of 0.0015 inch size), smoke particle (typically of 0.00025 inch size), finger print (typically of 0.00062 inch size) or a human hair (typically of 0.003 inch size) were placed on the disk surface, it would bridge the gap between the write heads and disk surface, causing the head to crash. A head crash, in which the head touches the disk, destroys the data stored in the crash and can destroy a read write head as well.

Internet of data cartridge


Digital audio tape is a type of magnetic tape that uses a same technology as helical scan to record data. A data cartridge is slightly larger than a credit card in width and height and contains a magnetic tape that can hold from 2 to 24 gb of data. it  can support data transfer rate of about 2 mbps. Like other types, data are sequential access media.
          Hard disks are used for on line secondary storage device for most computer systems today. The introduction of high capacity disks for microcomputer systems solved two problems related to the limited storage capacity of diskettes.
    First as a business began to use microcomputers extensively the amount of software acquired and data collected grew up substantially. Now a  day hard disks having capacity of several gb is available. So storage of huge amount of data is no problem.
   Secondary the largest file that could be accessed at one time was limited to the capacity of main memory and the storage medium. Since the capacity of hard disk is virtually unlimited, there is not constraint of accessing to any length of file.
  Data is stored in the same way as it on diskettes. A series of tracks are divided into sectors when the disk is formatted. As their name suggests, hard disks are made out of a rigid substance that is capable of storing a greater amount of data than the soft material used for diskettes. Hard disk drivers for microcomputer can be internal (built into the computer cabinet)or external (outside the computer cabinet and connected to it by a short cable).

Internet of Sequential and direct access device


Several i device can be used as a secondary storage, but the one selected for a particular application, mainly depends upon how the stored information needs to be access. There are two accessing information sequential or serial access and direct or random access.
             Sequential access storage device is one in which the arrival at the location desired may be   preceded by sequencing through other location, so that access time varies according to location. in other words, information on a sequential access device can only be retrieved in the same sequence in which it is stored. Sequential processing is quite suitable for such application like preparation of monthly pay slips, or monthly electricity bills etc. where most if not of all the data record need to be processed one after another.
  In these application, data record for every employee or customer needs to be processed at scheduled intervals in this case monthly. However while working with a sequential access device, if an address is required which out of order, if can only be reached by searching through all those addresses which are stored before it.

Saturday, June 25, 2011

Internet the Organization of a main memory having N words


You might have heart about 8 bit computer, 16 bit computer, 32 bit computers etc. This refers to the word length of the memory of a particular computer in terms of total number of bits per memory words. word length is an important architectural factor. Small machines have word length of 8,16 or 32 bits whereas large machines have word word lengths of 64 bits or more. what is the advantage of having more number of bits per word.
                   For the answer to the above question, if you have as 8 bits compute, if means that the word length of your computer is one byte, so the processor can access one byte 8 bit of data at a time. In a 16 bit computer the word length is two byte so the processor can access two bytes 16 bits memory to fetch the data to the cpu through  cache memory. Cache  memory if faster than the main memory.

Internet a floating Point representation


In floating point representation not only they are stored but the position of the decimal point is also taken  into consideration and stores separately.
                The actual number is termed as the mantissa and the decimal (binary) point is termed as the exponent. Depending upon the number system base or radix is assumed to be present but not defined.
                Foe example, if we have to represent 8.49, we can write it as 849 c 10-2 . This type of representation is called the scientific representation. Using this scientific representation, any number can be expressed as a combination of a mantissa and an exponent, or in other words, the number can be expressed as where is the mantissa is the radix of the number system and in the exponent.
                             Now converting the given number to the scientific from, we take.

Inter of the complements


The subtraction   performed in the example above contained the subtrahend   the number we subtract) less than minuend (the number that subtracts the other number ).  Now you know that subtraction might contain subtrahend greater than the minuend .On those situations the subtraction method will become less efficient .The make it easier additive approach known as complementary subtraction is used.
       In order to understand complementary subtraction, we need to know what complement of a number means. For a number, which has digit numbersital in it a complement is the difference between the number and the base raised to the nth power minus one.
                   When the value of the base r is substituted in the name,  the name types becomes2’s and 1’s complement for binary numbers and 10’s and 9’s complement for decimal numbers.
In the example above, we have 1 in the right most position so we place 1 in the right most position and then invert the remaining bits.
                 This can be illustrated using the following example.

Intenr of binary number system


It consists of only two numbers and hence this number system is also called base 2 or radix 2  number system.
                  As in the decimal number system, let us take us example of binary numbermatically as thes, which represents    more data than 0 and  1.   Let the binary number is 1101 and then as per the bit positions, each of the bit has a different weight. As shown in the case of decimal number system (base 10), the difference in weight will be in the multiple of base that is 2 in binary number system. So e can represent 1101 mathematically as below
                             Now you saw that when we use combination of 4 bits as above, we attained decimal 13. This means that if we want to represent 13, we should have at least four bits.
       Since, our basic objective is to represent decimal  number by binary digits, we have to find out how many bits are required to be combined in order to represent all digits of the decimal number system.
Let us start with 2 bits
Then the highest value would be

If the number system consists of 4-bit combination then it is termed as Hexadecimal Number   Symtem.  It is base 16 number system and hence consist of 16 numbers. Hexadecimal number is characterized by values between 0-15.But,since the digits after 9 are combined ,for example in 15,we have two decimal digits-1and 5.

Internet of decimal number system


The decimal number system consists of 10 independent number (0-9),and hence is called base 10 number system. To represent  numbers other than these, the independent numbers are combined .
               Let us take an example of 5678.we read this number as five thousand  six hundred and seventy eight .It is made from the addition of 5000,600,70and 8 (5678=5000+600+70+8).Now look at these numbers,5000 as a whole number does not lie in between 0 to 9 and similar is the case for 600 and 70.
                      Here ,we have used 5,6,7 and 8 to represent  a complete number five thousand six hundred  and seventy eight is different and that there weight or position (5 in the position of thousand,6 in hundreds,7 in tens and 8 in unit).
                                Here we see that the weight of 5 is the highest and that of 8 is the lowest. We should notice that the weight of each number differs from each other with multiple of 10. This means that the weight depends upon the radix or base. Also the weight has been increasing from side to the left.

Thursday, June 23, 2011

Internet of the computer represent data

We did say that computer understands 0s and 1s only,but if yoy look at our keyboard there are not only 0 and 1 but also other numbers,alphabetic letter and some specific characters. so this 0 and 1 have to represent all those.0 and 1 in computer are termed as bits binary digit.
                                  The number consititutes 0 and 9.Alphabetic letter constitutes (a-z A-Z)and special characters like and others,now look at the different data types that computer has to operat one by one .When we talk about number its generally 0 to 9 their combination 0 to 9 means that there are 10 different values .The number of independent different from each other values defines the base or radix of the system.In 0 and 9 there are ten independent values hence those numbers are said to be of decimal number system and are called to posses base 10 or radix 10.
                        you already know that data in computer is represented only in terms of 0 and 1 that is only two digital and if we write all the data in 0 and 1 then we  call it binary number system.
0 and  1 are independently called bits.since there are only two individual bits present to define more than two number we have to have the combination of bits 0 and 1. if the combination is of 4 bits  then it is termed as nibble.if it combination is of 8 bits then it is termed as byte.It the combination is of 16 bits then it is called a word.

Wednesday, June 22, 2011

Internet of the Number system

To start up with lets look back at what computer is.computer is an electronic electromechanical ta be precise device that can take inpute,process it and give the desired output with the facility of storing the output.
                 Now to be exact for a computer to function,we must feet something to it.We do it through the input device.The simplest input device is the keyboard.When you press a key,the corresponding aiphabet appears on the output device ,monitor.How is this possible the monitor and keyboard are complected different device.The only common thing between them is that they are both connected to cpu.so how does aiphabet appear on the monitor when we press a key there might be something that two devices and that is electricity.
                  You will also agree that if there is no electricity or the source of power,and then the computer cannot operate.So the basic operation of a computer is purely by the use of electricity.Now the question may arise how electricity helps attain the exact letter that we pressed.here we are  talking about the characteritics of a computer,which demands accuracy and reliability.
                   Let,s first know that electricity is measured in terms of voltage and current.now when you press the letters,voltage we usually use voltage as a measurement of electricity for digital data is generated only from that part the area where the key is placed.


Internet of the personal computer

Personal computer is a non portable,general-purpose computer which can easily fit on a normal size office cable (leaving some writing space to keep writing pads and others oriented ).and is gener.seally designed to be used by one person at a time single user oriented personal computers were mainly designes to meet the personal com puting needs of individuals,either in either in their working places or at their homes.In fact personal computer have changed the work culture and work habits of numberous organization and individuals.an increasing proportion of office work now in volves the use of computer .hence today personal computers are found on the working desks of several employees,in any organization.personal computer  are also providing employees can do a work at their office and continue it at home.several individuals also keeps a personal computer in their homes to run business at homes.Personal computer are used by people of all ages for education,entertainment and others.Hence personal computer have now very common and can be found everywhere like offices,classrooms,homes,hospitals,shops,clinics etc.
                                                          The configuration of personal computer varies from one personal computer to another,depending on their usege.however the most commonly used configuration consists os a system unit a monitor dispaly screen a keyboard and a mouse.The system unit,which is in the form of a box,consists of the main circuit board  of cpu,memory etc.The hard disk storage the floppy disk drive the cd Rom drive,any special add on cards such as network interface card and ports for connecting peripheral devices such as printer.


Internet of computer in society

The technology in computers is developing and so fact that yesterday high end machine become a very low end one today.for example in 1994,486 bades system was high end computer and today they are obsolete.pentium based system are taking overs fact.computer were so expensive that people at large were unable to affordable it.Now,the pric e of computer have drastically gone down,making it afforrdable to many.today computer has become indipens able in every household.It is extensively used in medicine,education,weather forecasting,scientific works etc.There is hardly any field,which is without the impact of computer.Its impact on society is clear.We are going to discuss its impact in terms of social application and economic effects.

                    The impact of computers in industry is related to the achievement of automation and cybernation.the term automation means the use of computers to control others machines and physical processes without human intervention.The term cybernation puts emphasis on outomatic control aspect of outomatic self regulation process control system.In these areas,the computer tries to replace some of the human brain power .For example in the area of office automation,a computer performs the tradition clerical tasks.
              The competition among various industries has increased in the sense that previously small industries .survive because of the inefficincies of large industries.Computers have allowed large industries to become more efficient thereby forcing the smaller industries to grow in terms of people and production facilities.Since the cost of computer is coming down every year,even smaller industries can take advantage of the productivity generated by computerization.

                   








Internet of Introduction

Computers are the greatest achievement of your time.It is difficult to imagine a day that is not in some way affected by computer. In a relatively short time span computers have affected many areas of your lives as they are extensive used in agriculture,medicine,education,publishing,business,transpotation ect.In fact,there there is hardly any field left,which is not directly or indirectly affected by computer.But most importantly,computers have had a tremendous impact on the way information is processed within organizations.Although information had been processed manually thoughtout history,modern management information systems would not be possible within computer.
           Computers have changed completely the way of conducting the business.Large volumes of accouting and record keeping data can be manipulated,organized,stored,retrieved,and used for specific purposes with greater ease.Bills and statements can be processed and sent to customers in much less time and with much less effort.financial projections are made with greater ease as computer helps managers to organize and manipulate financial data.Any combination of factors and their effect on the overall process can be tested.Planning and decision making thus become mare efficient and accurate.

Internet is a Topology


Topology is the physical layout of computer which describes that how computers are connected,         arranged, managed, and flow of the data from one host to another host. There are different kinds of topology:
  In Bus topology, we can connect maximum 30 computers with 100 meters of coaxial cable. We use terminator cap at the end of the both side of the coaxial cable to block the flow of information. In this topology, we use BNC connector, T connector, LAN card, Terminator cable to connect the computers on the network. If the main cable will fail, it will affect the entire network.
  In Ring topology, all the computers are connected in circular form same as ring. Its data flows in only one direction. So, if one computer fails, the remaining computer on its anti clock wise direction cannot access the data same as Bus topology. We can connect here maximum 30 computers with 100 meters of coaxial cable. In Ring topology, the terminator point and the terminator cable are not used.
   In Star topology, all the computers are connected with the help of switch or hub for the local LAN and we use repeater, router to connect the different LANs of Star topology. In this topology, if one computer will fails it will not affect another computer on the network. But if central connectivity device fails, it will affect the entire network. It uses more cable. We use twisted pair cable, NIC, RJ-45, switch/Hub to connect the computers on the network.
 With the hybrid topology, two or more topologies are combined to form a complete network. For example, a hybrid topology could be the combination of a star and bus topology. These are also the most common in use.
           In a mesh topology, each computer is connected to every other computer by a separate cable. This configuration provides redundant paths through the new work, so if one computer blows up, you don't lose the network. On a large scale, you can connect multiple LANs using mesh topology with leased telephone lines, Thicknet coaxial cable or fiber optic cable.
Again, the big advantage of this topology is its backup capabilities by providing multiple paths through the network.

Internet of the divice


Network is data communication mechanism (device).
Computer network is the process of connecting two or more than two computers to share the data and resources.
The resources can be any peripheral devices such as CD-ROM, Pen drive, Hard disk drive, Printer etc. and the data can be the folders and the files available in the share folder because a file is shared only when that file is available in the shared folder.
(a)  On the basis of Media: - On the basis of media there are two kinds of network.
(i)   Wired (Guided) Media: - On the guided media, we can establish the network physically with the help of coaxial cable twisted pair cable, NIC, RJ 45, RJ 11, Fiber Optic cable etc.
(ii)  Unwired (Unguided) Media: - This type of network is created with the help of WAP (Wireless Access Protocol). The wireless media uses USB, NIC, Infrared, Radio wave, Bluetooth, Link Sys, and Router etc.
(b)  On the basis of Scope: - On the basis of scope there are three kinds of network. This is also called the network on geographical base. They are as follows:
(i)   LAN (Local Area Network): - When the network is established in a single room, single floor, or in a single building within 500 meters of long distance then it is called LAN. In this network, we can connect maximum of 254 computers. A LAN can be both the wired and unwired.
(ii)  MAN (Metropolitan Area Network): - When two or more than two LAN(s) are connected with the help of Repeater, Router etc. then it is known as MAN.
(iii) WAN (Wide Area Network): - When the network expands country wise, within continent or world wise then it is called WAN. To establish the network of WAN, we use VSAT (Very Small Aperture Terminal) or Satellite.
(c)  On the basis of Function/Model: - On the basis of function there are two kinds of network:
(i)   Peer to Peer Network: - In this network, we use the client Operating system. We can also use the server operating system. But the services of server cannot be taken from it. In this network, all the computers are administrated or managed individually. We assume a computer as a server. This type of network is useful for small organization. It has no server so has no security.

Internet of the worldwide


The Internet is a network, or system, that connects millions of computers worldwide. It was one of the greatest inventions of the 1900s. Today the Internet helps many people communicate, work, learn, and have fun.
In the 1960s the U.S. government, businesses, and colleges worked together to make a system that would let computers across the United States share information. They created an early form of the Internet called ARPANET in 1969. In 1971 electronic mail, or e-mail, was invented as a way to send a message from one computer to another.
By the mid-1970s many groups of computers were connected in networks. Machines called routers were invented to connect the networks. This is how the original ARPANET eventually grew into the Internet.
In 1989 hypertext was invented. Hypertext is a link between different parts of an electronic document or between different documents. Hypertext became the basis of the World Wide Web, or “the Web,” which was created in the early 1990s.
Information on the Web is arranged in sites or pages. People view Web sites using computer programs called Internet browsers. People create Web sites using a code called hypertext markup language, or HTML. Browsers read HTML and allow people to view Web sites on the computer. Each Web site has its own Internet address, called a uniform resource locator, or URL.

Tuesday, June 21, 2011

Inter of the networking

The internet is a network of the interluked computer networking worldwide,which is acemiblc to general public.these internetconnected computer work by lransometeeiy data through a opectical type of packet shuthey which is know as the ip or internet protocal .
               Internet brings us a whole host of capabilites. We can take advartage of internet in following webside.communication thth others and lranmiathy file via and like meded indidaded .

requesty penusaiy am she with proble and quesstion.

Internet a Voip

The most prominent component of the Internet model is the Internet Protocol (IP) which provides addressing systems (IP addresses) for computers on the Internet. IP enables internetworking and essentially establishes the Internet itself. IP Version 4 (IPv4) is the initial version used on the first generation of the today's Internet and is still in dominant use.internet of the man world are voip of the man internet throth Ip address of the internet of the voip.personal computers. In recent years many VoIP systems have become as easy to use and as convenient as a normal telephone. The benefit is that, as the Internet carries the voice traffic, VoIP can be free or cost much less than a traditional telephone call, especially over long distances and especially for those with always-on Internet connections such as cable or ADSL. VoIP is maturing into a competitive alternative to traditional telephone service. Interoperability between different providers has improved and the ability to call or receive a call from a traditional telephone is available

Internet inshort

Internet is a short form of the technical term internetwork,the result of interconnecting computer networks with special gateways or routers. The Internet is a router three and four computer of the networking.Internet of the google searching songs music,map.It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet.Inter online of the rodio ,friends online of the chating and skype account on the friends is a tacking. The most prominent component of the Internet model is the Internet Protocol (IP) which provides addressing systems (IP addresses) for computers on the Internet. IP enables internetworking and essentially establishes the Internet itself. IP Version 4 (IPv4) is the initial version used on the first generation of the today's Internet and is still in dominant use.

Internet a Global System


The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide.Internet is a beter sarbice internet of which coury of the cantact of the man.Internet mail friend online chating.Internet of the world searching.The origins of the Internet reach back to research of the world map,online of the man cantact and friend online the taking.Internet of networking.It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies.