Computer memory

 Computer memory:

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations. (June 2011)In computing, memory refers to the physical devices used to store programs (sequences of instructions) or data (e.g. program state information) on a temporary or permanent basis for use in a computer or other digital electronic device. The term primary memory is used for the information in physical systems which are fast (i.e. RAM), as a distinction from secondary memory, which are physical devices for program and data storage which are slow to access but offer higher memory capacity. Primary memory stored on secondary memory is called "virtual memory".

The term "storage" is often (but not always) used in separate computers of traditional secondary memory such as tape, magnetic disks and optical discs (CD-ROM and DVD-ROM). The term "memory" is often (but not always) associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based transistors, used for example as primary memory but also other purposes in computers and other digital electronic devices.

There are two main types of semiconductor memory: volatile and non-volatile. Examples of non-volatile memory are flash memory (sometimes used as secondary, sometimes primary computer memory) and ROM/ PROM/ EP ROM/ EEP ROM memory (used for firmware such as boot programs). Examples of volatile memory are primary memory (typically dynamic RAM, DRAM), and fast CPU cache memory (typically static RAM, S RAM, which is fast but energy-consuming and offer lower memory capacity per area unit than DRAM) .

Volatile memory:

Volatile memory is computer memory that requires power to maintain the stored information. Most modern semiconductor volatile memory is either Static RAM (see S RAM) or dynamic RAM (see DRAM). S RAM retains its contents as long as the power is connected and is easy to interface to but uses six transistors per bit. Dynamic RAM is more complicated to interface to and control and needs regular refresh cycles to prevent its contents being lost. However, DRAM uses only one transistor and a capacitor per bit, allowing it to reach much higher densities and, with more bits on a memory chip, be much cheaper per bit. S RAM is not worthwhile for desktop system memory, where DRAM dominates, but is used for their cache memories. S RAM is commonplace in small embedded systems, which might only need tens of kilobytes or less. Forthcoming volatile memory technologies that hope to replace or compete with S RAM and DRAM.

Non-volatile memory: 

Non-volatile memory is computer memory that can retain the stored information even when not powered. Examples of non-volatile memory include read-only memory (see ROM), flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy discs and magnetic tape), optical discs, and early computer storage methods such as paper tape and punched cards. Forthcoming non-volatile memory technologies include Fe RAM, CB RAM, PRAM, SO NOS, R RAM, Racetrack memory, N RAM and Millipede

Block Diagram Of Computer: 

A computer is designed using four basic units, they are:

1. Input Unit.

2. Central Processing Unit (CPU).    

     (a) Control Unit.    

     (b) Arithmetic and Logic Unit.

     (c) Registers.

 3. Memory Unit.

 4. Output Unit.

Input Device:Computers need to receive data and instruction in order to solve any problem. The Input Unit performs this operation. The input unit basically links the external world to the computer. The input unit consist of one or more input devices.Example:Keyboard, mouse.

Central Processing Unit (CPU):The CPU is known to be heart or brain of he computer system and the program to manipulate data into information.

Control unit: Control Unit refers to a functional unit which carries out four basic operations.

1.Fetches an instruction.

2.Decode the instruction.

3.Executes the instruction.

4.It stores the results.

Arithmetic Logic Unit: Arithmetic Logic Unit performs arithmetic and logic operations and controls the speed of these operations.Logic operations are like AND, OR, NOT.

arithmetic operations are like addition, subtraction, multiplication and division.

Register: Registers are high speed storage areas that temporarily store data during processing to enhance computer's performance.

Memory Unit: Memory Unit is an essential component of any digital computer, It is a storing device. It stores programs and data, which are required by the CPU, and the result after processing.

Output Devices:The output unit converts the data from binary form to the human understandable form before it displays the result.

                          

Computers in Fashion

Computer in Fashion:

Over the decades computers and fashion have developed gradually, changed with time, taste and trend. But nobody knew that a time will come when both these fields will complement each other so well. Today fashion design has reached new heights by computer aided methods of design. As a result of which, computer industry has got its new customer. Computer technology is making waves in the fashion design zone. From determining textile weaves to sizing designs; computers are a vital component of the fashion industry. Computer aided design (CAD) programs reduce the demand for manual sketches. New software programs continue to replace old manual skills. Going by the wayside are "old fashioned" flat pattern construction, pencil sketching and traditional math-based pattern sizing. Those who lag in math and falter at sketching can now breathe a little easier. 

Computer-aided design (CAD), also known as computer-aided design and drafting (CADD), is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer. CADD software, or environments, provides the user with input-tools for the purpose of streamlining design processes; drafting, documentation, and manufacturing processes. CAD may be used to design curves and figures in two-dimensional (2D) space; or curves, surfaces, and solids in three-dimensional (3D) objects.

Although most designers initially sketch designs by hand, a growing number also translate these hand sketches to the computer. CAD allows designers to view designs of clothing on virtual models and in various colors and shapes, thus saving time by requiring fewer adjustments of prototypes and samples later.

Most fashion design colleges, however, still teach traditional design methods, including manual flat pattern construction, draping and line drawing. No doubt that learning of these methods are essential for having a good idea about fashion design but Cutting-edge education also focuses on computer aided methods of design. Software can help students draw, create woven textures, drape models to create patterns, adjust sizes and even determine fabric colors. By Introducing this technological aspect will enable students to understand a lot better and try various combinations in their design. This also cuts down the time factor i.e. by use of CAD methods students can learn a lot faster and more software in less time but Fashion Design is not an easy profession. You dont have to word hard rather WORK SMART. 

Its not that one should neglect the manual design methods and completely focus on CAD methods. State-of-the-art technology is important, but a sound understanding of the methods behind production is also essential. Manually figuring size adjustments and cutting pattern pieces instills that knowledge. Software programs constantly evolve. A program used today may be obsolete within several years. Being trained on today's software does not guarantee it will be used when you are ready to go out into the field. Understanding calculations is timeless, as is computer competency. Software, however, shifts rapidly. 

Sketching remains a basic design skill. The option now exists to create computer generated drawings of your work. Take advantage of the old and new. Master the ability to sketch on paper and perfect your skills as a computer-aided designer. Masterful sketches, whether hand-drawn or computer-generated, are what sell your designs. Fashion continues to evolve with computer technology pointing forward. You must not lag behind. Yet you should not forge forward without a sound understanding of the basics. Computer technology is the prevalent method for both knit and woven pattern construction and is coming to the forefront as the sketching method of choice. Learn the necessary technologies to stay on fashion's forefront.

 

Classification Of Computer

Analog Computer:
The main advantage of analog computer is that all calculations take place in parallel these are faster analog information is mechanical it processes limited accuracy.

Digital Computer:
The digital computer work upon discontinuous data. They convert the data into digits (binary 1 and 0). Digital computers very much faster then analog computers. Digital computers can further classified in two ways:

 

 1.Purpose wise: Digital computers are classified into two types:
 

(a) Special purpose computer:
    Is the one that is designed to perform a specific task.Instructions carry out the task are permanently stored in the machine.Computers are not versatile.

(b) General purpose computer:
    Is the one that can work on different types of programs input. Programs are not permanently stored. These computers are versatile.

2.Size and performance wise:Computer can be classified in to following four types:
 

(a) Microcomputers: Microcomputer are also known as personal computers. This is the most prevalent form of computer and standard desktop.The first PC was built by IBM.

(b) Minicomputers: Minicomputers is type of computer. It is usually designed for real time dedicated as high performance for an operating system. Minicomputer are the digital Alpha.

(c) Mainframes: Mainframes which require high performance and generate. It process large numbers of transactions on mainframes. To process high volumes of ATM,check and electronic transaction. The most mainframes are manufactures.

(d) Supercomputers: Supercomputers are designed for ultra high performance tasks.
Supercomputer owned by government agencies. It is a generally accepted fact that the National Security Agency (NSA).

Computer system characteristics and capabilities:
 

1.Speed:The speed of a computer is closely related to the amount of data it must process.
2.Accuracy: Computer systems are particular adept at repetitive task because of their reliability.
3.Reliability: Computer system are widely accepted because of their exceptional reliability.
4.Storage Capability: System have total and instant recall of data and an almost unlimited capacity.

Characteristics of personal computer:
 

1.Laptops:They are expensive than desktops, they very smaller in size.It has same power as of desktop computers.Weight around 3 to 5 kilograms.

2.Notebooks:They are powerful as desktop, the size is very small like a note book.
They are more costly, weight around 2 to3 kilograms.

3.Palmtops:Also known as Personal Digital Assistant. The size of a human hand they can do word processing, spreadsheet calculations, handwriting recognition. They are not as powerful as the desktop computers.

4.Wearable computers:The size is very small, it can be worn on the body itself,It as smaller processing power.Its application in the field of medicine.

Appplications Of Computer

 1.Computer in Education:
               

                       Back to the 1940s, the modern electronic computer was developed at U.S. universities; however, in the year, there was no computer education yet. It needed more 10 years to have computer education. The period of the computer revolution was 1950 in the U.S.. Computer education began in the middle of the 1950s with an organized body of knowledge. Also Japanese the teaching of computer science has been developed in the same period. During 1955 to 1959, some universities developed their own computers. They organized short courses.
                    
                   Computer technology comes from the U.S. to Japan. Usually a technology is developed in the U.S.. After that, it comes to Japan so Japanese computer education is late at all and most manuals are written in English so it iseasy to lean computer for people who speak English; however, most Japanese people who live in Japan cannot understand English so they have to translate English to Japanese to understand the manuals. It needs much time. Usually Japanese universities teach computer to students in Japanese so students have to study not only computer but also English when they try to use computer even if they can use Japanese operating system. For example, the command of tcomputer programming languages are written in English so Japanese students have to have dictionary their hand, therefore, some students stop learning it. It is so hard for Japanese student.
                  
                  In the near future, computer technology will be needed and important for not only students who want to be programmers or engineers but also general Japanese people so Japanese computer education has to find their own computer educational system so that people who have no computer knowledge can learn it easily.

2.Computer in Industry:
                 

               Computers are used in industry in different types of systems.
Computer-controlled robots are used to perform many complicated jobs in industry. Robots are computer controlled programmable machines. They can perform mechanical jobs, too, like pick and place different parts, welding or painting cars etc.oday, computer-controlled robots are used to assemble cars. No doubt, these systems work faster than human beings. Another popular and efficient use for computer controlled robots is in the field of spray painting.
               

                 The consistency and repeatability of a robot's motion have enabled near perfect quality painting while at the same time wasting no paint and leaving no place without paint.Perhaps the most popular applications of robots are in industrial welding. The repeatability, uniformity quality, and speed of robotic welding is unmatched.Computer controlled Robots can be found in the manufacturing industry, the military, space exploration, transportation, and medical applications.

                 Computer programs are used to design the model of a product on the computer. This process is called Computer Aided Design or CAD. Due to CAD, we
can test the designed product with the help of computer. When the design is completed successfully, the actual product is manufactured. 

3.Computers in Business:
                  

                   Computers have tremendously improved the way businesses operate in their respective industries. Technology has advanced so remarkably that those who are not using computers in their business are at a major disadvantage against their competitors. In particular, there are several important advantages that computers can provide to small businesses.

                  Computers allow the application of different types of software that can help businesses keep track of their files, documents, schedules and deadlines. Computers also allow businesses to organize all of their information in a very accessible manner. The ability to store large amounts of data on a computer is convenient and inexpensive, and saves space. A computer's ability to allow a company to organize its files efficiently leads to better time management and productivity.

                Computers have made staff and companies more self-sufficient by allowing them to do tasks that previously had to be outsourced. For example, a company can now use office software to create their own training material. Desktop publishing software can be used to create marketing materials. Online tax and accounting programs allow companies to prepare their own taxes. This allows the dominant operations of a company to remain in-house and empowers the company to become more independent and less susceptible to errors committed by outside parties.

4.Computer in Communication:
                   

                         Humans have always communicated. In the beginning of mankind, man and woman used speech and body languages. Nowadays, we also use telecommunication technology for communication. During the relative short era of computers we have developed languages and rules for communication between them. These languages and rules are called protocols. The most well known protocols are TCP/IP, used in the Internet.In our research, we focus on radio based computer communication. Our vision is to provide the same mobility to the user as the cellular phone, with the same communication performance, cost and quality as the fixed wired networks.

                    In the future, computers will be so common in our everyday appliances and mobile units that we will not react on them. Wireless embedded sensor networks with powerful CPUs will be common. All these computers will be able to communicate with each other, often over wireless networks. But, in the future we will not have the time, or the desire to configure this massive amount of computers and networks that we constantly will have around us. Instead, the computers must configure and set-up networks themselves for their task at hand. a ignificant part of our research studies such spontaneous autonomic networks, created for the situation and moment. It could be an ad-ho network of mobile phones for a disaster area where the stationary infra-structure is broken. A major part of our research is in the area wireless sensor networks within the Uppsala WISENET center of Excellence.

                   These self-configuring protocols must be trustworthy, i.e. reliable and secure, to be accepted. We study how authentication of correct users can be done automatically and how protocols could ensure transmission integrity when computers join and leave different networks. Another important property for trustworthiness is the resilience against computer viruses and other malicious attacks.

5.Computers in Entertainment and multimedia:
                     

                 Computers are used in entertainment to creat or enhance a production or performance. The tools have become almost impossible to distinguish between the real and the artificial in film and photography.A wide range of theoretical and practical computer applications in the entertainment industry, including engagement, playfulness, creative technique, business, separability, and “funology.” CiE publishes peer-reviewed research papers and articles, as well as commentaries, opinion articles, video interviews as well as their transcriptions, creative content such as games and artwork, and more.

                      A multimedia computer is a computer that is optimized for high multimedia performance, enabling rich multimedia experience.Early home computers lacked the pow and storage necessary for true multimedia. The games for these systems, along with the demo scene were able to achieve high sophistication and technical polish using only simple, blocky graphics and digitally generated sound.The Amiga 1000 from Commodore International has been called the first multimedia computer.

                        Most PCs today have good multimedia features. They have dual- or single-core C Pus clocked at 3.0 GHz or faster, at least 1GB of RAM, a 128 MB or higher video card and TV Tuner card. Popular graphics cards include Dravidian G force or ATI Radon. The Intel Vi iv platform, and Microsoft Windows XP Media Center Edition are some of today's products aimed at multimedia computing. 

Generations Of Modern Computers

First Generations Computers (1945-1956)
     
        With the onset of the second world war, governments sought to develop computers to exploit their potential strategic importance. This increased funding for computer development projects hastened technical.American efforts produced a broader achievement Howard H Al ken a Harvard engineer working with IBM, succeeded in producing an all-electronic calculate by 1944. The purpose of the computer was to create ballistic charts for the U.S.Navy. It was called Mark 1 an electronic relay computer.


           The features of first generation of modern computers they are:
                         * Vacuum tubes for internal operations.
                         * Magnetic drums were used for memory.
                         * Processing speed is very slow.
                         * It is very expensive.
                         * It do not have much memory.

      
Second Generation Computer (1956-1963)

         In 1948, the invention of the transistor greatly changed the computer's development. The transistor was at work in the computer by 1956. Coupled with early advances in magnetic-core memory, transistors led to second generation computers that were smaller, faster, more reliable and more energy-efficient than their predecessors. The first large scale machines to take advantages of this transistors technology were early supercomputers.

                  
            The features of second generation of modern computers they are:    
                         * Transistors were used for internal operations.
                         * Magnetic cores were used for main memory.
                         * High level language were used.
                         * Magnetic tapes and disks were used.
                         * The systems were faster, small in size, cheaper and power full.


Third Generation Computer (1964-1971)     
         
             As a result, computer became ever smaller as more components were squeezed on to the chip. The third generation computer was announced in1964 by IBM with its 360 line of computers, which used integrated circuits in the hardware. Another third generation development included the use of an operating system that allows machines to run many different programs at once with a central program that monitor and coordinated the computer's memory.


               The features of third generation of modern computers they are:
                * Integrated circuits on silicon chips were used for internal                                        operations.     
                               * Minicomputers were introduced.
                               * Emergence of the software industry.
                               * Systems were totally used for general purpose.
                               * The systems were faster, cheaper and power full. 


Forth Generation Computer (1971-Present)
                Such condensed power allowed every day people to harness to a computer's power. By the mid 1970's computer manufacture sought to bring computer to general consumers. These minicomputers came complete with user friendly software packages that offered even non-technical user an array of applications most popularly word processing and spreadsheet program's In 1981 IBM introduce its Personal Computer to use in the home.

                  The features of forth generation of modern computers they are:
                                 * Introduction of microprocessor.
                                 * Use of chips for memory.
                                 * Microcomputers and personal computers were used.
                                 * Hardware failures were negligible.
                                 * The systems were faster, cheaper and size is small.

Fifth Generation Computer (Present-Beyond)

             Fifth generation computer will incorporate artificial intelligence which will not be far different form that of human intelligence and will store reservoirs and decisions. They will process non numerical information such as pictures and graphs. In these systems intelligence will be greatly improved and when compared to then conventional machine, the man machine interface will be closer to the human system.
                 
             The features of fifth generation of modern computers they are: 
                  * Development of storage technology.
                  * Development of robots.
                  * Computers are more intelligent.
                  * Development of supercomputer.
                  * System are more power full, cheaper and faster.