Download computer generation and more Essays (university) Computer Applications in PDF only on Docsity!
WHAT IS A COMPUTER?
Computer is an advanced electronic device that takes input raw data from the user and processesthese data under the control of set of instructions ( set of instraction called program) and gives the desired result as output and may saves output for the future use and print the result in desired format. A computer has four functions:
- Accepts data (Input)
- Processes data (Processing)
- Produces result (Output)
- stores results (Storage) A computer System: All of the components of a computer system can be summarized as- COMPUTER SYSTEM = HARDWARE + SOFTWARE+ USER
- Hardware = Internal Devices + Peripheral Devices ( All physical parts of the computer. )
- Software = Programs (Software gives "intelligence" to the computer.)
- User = Person (who operates computer.)
Block diagram of computer
Functionalities of a computer
Any digital computer carries out five functions.
- Takes data as input. (Input)
- Stores the data/instructions in its memory and use them when required. ( Memory Unit )
- Processes the data and converts it into useful information. ( ALU )
- Generates the output (Output)
- Controls all the above four steps ( Control Unit)
Input : This is the process of entering data and programs into the computer system. › Memory Unit : Computer is used to store data and instructions. › Arithmetic Logic Unit (ALU): The major operations performed by the ALU are addition, subtraction, multiplication, division, logic and comparison. › Output : This is the process of producing results from the data for getting useful information. › Control Unit : The process of input, output, processing and storage is performed under the supervision of a unit called 'Control Unit'. It decides when to start receiving data, when to stop it, where to store data, etc. It takes care of step -by-step processing of all operations in side the computer.
Input Unit : This unit contains devices with the help of which we enter data into computer. This unit makes link between user and computer. The input devices translate the information into the form understandable by computer. › Central Processing Unit ( CPU ) : CPU is considered as the brain of the computer. CPU performs all types of data processing operations. It stores data, intermediate results and instructions(program).It controls the operation of all parts of computer. CPU itself has following three components ALU(Arithmetic Logic Unit) Memory Unit Control Unit ALU( Arithmetic Logic Unit ) Function of arithmetic section is to perform arithmetic operations like addition, subtraction, multiplication and division and logical section perform logic operations such as comparing, selecting, matching and merging of data. Memory Unit This unit can store instructions, data and intermediate results. This unit supplies information to the other units of the computer when needed. It is also known as internal storage unit or main memory or primary storage or Random access memory (RAM). Control Unit : The process of input, output, processing and storage is performed under the supervision of a unit called 'Control Unit'. It decides when to start receiving data, when to stop it, where to store data, etc. It takes care of step -by-step processing of all operations in side the computer.
CHARACTERISTICS OF COMPUTER Speed: As you know computer can work very fast. It takes only few seconds for calculations that we take hours to complete. Accuracy: Suppose some one calculates faster but commits a lot of errors in computing. Such result is useless The degree of accuracy of computer is very high and every calculation is performed with the same accuracy. The accuracy level is determined on the basis of design of computer. The errors in computer are due to human and inaccurate data. 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
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 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
COMPUTER GENERATIONS
You know that the evolution of computer started from 16th century and resulted in the form that we see today. The present day computer, however, has also undergone rapid change during the last fifty years. This period, during which the evolution of computer took place, can be divided into five distinct phases known as Generations of Computers. Each phase is distinguished from others on the basis of the type of switching circuits used
Other Important Computers of First Generation EDSAC: It stands for Electronic Delay Storage Automatic Computer UNIVAC-1 : Ecker and Mauchly produced it in 1951 by Universal Accounting Computer setup. Limitations of First Generation Computer Followings are the major drawbacks of First generation computers. 1. The operating speed was quite slow. 2. Power consumption was very high. 3. It required large space for installation. 4. The programming capability was quite low.
2 Second Generation Computers Around 1955 a device called Transistor replaced the bulky electric tubes in the first generation computer. Transistors are smaller than electric tubes and have higher operating speed. They have no filament and require no heating. Manufacturing cost was also very low. Thus the size of the computer got reduced considerably. It is in the second generation that the concept of Central Processing Unit (CPU), memory, programming language and input and output units were developed. The programming languages such as COBOL, FORTRAN were developed during this period. Some of the computers of the Second Generation were IBM 1620. IBM 1401: CDC 3600:
Fourth Generation Computers The present day computers that you see today are the fourth generation computers that started around 1975. It uses large scale Integrated Circuits (LSIC) built on a single silicon chip called microprocessors. Due to the development of microprocessor it is possible to place computer’s central processing unit (CPU) on single chip. These computers are called microcomputers. Later very large scale Integrated Circuits (VLSIC) replaced LSICs. Thus the computer which was occupying a very large room in earlier days can now be placed on a table. The personal computer (PC) that you see in your school is a Fourth Generation Computer.
5 Fifth Generation Computer
The computers of 1990s are said to be Fifth Generation computers. The speed is extremely high in fifth generation computer. Apart from this it can perform parallel processing. The concept of Artificial intelligence has been introduced to allow the computer to take its own decision. It is still in a developmental stage.
Banking: Today, banking is almost totally dependent on computers. Banks provide the following facilities − Online accounting facility, which includes checking current balance, making deposits and overdrafts, checking interest charges, shares, and trustee records. ATM machines which are completely automated are making it even easier for customers to deal with banks
Insurance: Insurance companies are keeping all records up- to-date with the help of computers. Insurance companies, finance houses, and stock broking firms are widely using computers for their concerns. Insurance companies are maintaining a database of all clients with information showing − (^) Procedure to continue with policies (^) Starting date of the policies (^) Next due installment of a policy (^) Maturity date (^) Interests due (^) Survival benefits (^) Bonus
