Welcome To Blog Of  Computer

Introduction:

The term computer is derived from the world "computer" which means 'to calculate'. We all are familiar with calculate in our day-to-day life. We apply mathematical operations like addition, subtraction, multiplication, etc. and much other formula for calculation. Simpler calculation take 

less time. But complex calculations take much longer time. Another factor is accuracy in calculations. So man explored with the idea to develop a machine, which can perform this type of arithmetic calculation faster, and with full accuracy. This gave birth to a device or machine ' computer'.

A computer is an electronic device, operating under the control of instruction stored it its own memory that can accepts data, manipulate the data according to specified rules, produce results, and store the results for future use. It is an electronic device for processing data that takes data input from its users, stores, process data and generates the required output as per the processing instructions given to it by the user.

Computer is an electronic device that accents data through input device then store and store and process them, and resulted data are displayed from output device. A computer is a programmable

machine capable of:

1)Take input raw-data through the input device such keyboard, mouse or any input devices.

2)Storing the input data into main memory and disks such hard disk, CD or other medium.

3)Processing it at the center processing unit (CPU) and

4)Giving out the result as output on the screen or the any visual display unit.

A computer is an electronic device, operating under the control of

instruction stored in its own memory, that can accept data,according to specified rules, produce results, and stores for future use.

Digital and Analog Computers

Digital Computer

A digital computer is one that works with binary digits (0s and1s). It is based on digital signals i.e.

discrete signals. Digital computer doesn't measure the physical values. It operates on data, including

magnitudes, letters, and symbols,that are expressed in binary form-i.e.,using only the two digits 0 and 1. A digital machine is usually a general-purpose device, dedicated to a multiple task.These computer are mostly used in the preparation of reports, results. They were large machines consuming large amounts of electric power and hence expensive and mechanical computer had the advantage over 

digital computers. Most computer today are digital computer had the advantage over digital computers. Most computers today are digital computer. Examples of these computer are IBM PC,

Apple/Macintosh etc.

Analog Computer

Analog computer is one which operates on continuous data, usually of a physical nature such as length, voltage or current etc. An analog computer is usually a special-purpose computer,dedicated

to a single task. Analog computer are based on analog signals that are continuous signals. An analog

computer does not use discrete(exact) values, but rather continuous (approximate) values; processes

cannot be reproduced with exact equivalence, as they can with Turing machines. These types of computer were widely used in scientific and industrial applications where digital computer of the time lacked sufficient performance. These are used in hospital to measure the size of stone in kidney and mental diseases diagnostics(CT scan with photos). It is powerful in solving differential equations

.Analog computer represent physical quantities in the form of wave or in continuous form. Examples

of analog computer are 'Plesley', slide rule, speedometer, thermometer,barometer,lactometer,seismog-

raph etc.

 Characteristics of a computer

As we know, a computer is the powerful electronic device. It can use to process large amount of data and information. It is never get 

tired, can perform repeative tasks. The main characterstics of computer are given below.

Word Length

A digital computer operates on binary digits-0 and 1. It manipulates

data only in terms of 0 and 1. A binary digit is called a bit. The number of bits that a computer can process at a time in parallel is called its word length. World lengths of computer i.e. the longer the more powerful the computer is. When we talk of a 16-bit computer, it means that its word length is 

16 bits.

Speed

The time taken to perform any task by computer is called seed of computer. As you know computer can work very fast. It task only

few second for calculation that we take hour to complete. The speed

of computer in terms of microsecond (10-6 part of a second)or nano

-second (10-9 part of a second). From this you can imagine how fast your computer performs work. 

Accuracy

Computer is the accurate machine. The degree of accuracy of computer is very high and every 

calculation is performed with same accuracy. It can perform large number of task with out errors

but if we need wrong data to the computer it returns the same wrong information called GIGO (Garbage in garbage out). Suppose some one calculate faster but commits a lot of errors in computing .

Such result is useless. There is another aspect. Suppose you want to divide 15 by 7. You may work out up to 2 decimal places and say the divided is 2.14. I may calculate up to 4 decimal places and say 

that the result is 2.1428. Some one else may go up to 9 decimal place and say the result is 2.142857143. Hence, in addition to speed ,the computer should have accuracy or correctness in computing.

Diligence

The capacity of the performing repetitive task free from tiredness,

lack of concentration and fatigue is called diligence capacity of

computer. It can work for hour 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.

Versatility

The capacity of performing more than one work is called versatility of computer. It means the capacity to perform completely different type of work. Computer are flexible to performs both simple and complex tasks. It can perform different tasks depending upon the different programs fed to it. You may use your computer 

to prepare payroll slips, office work, mathematical calculation, word processing etc

Storage

The computer has mass storage section where we can store large volume of data for future work.Such data are easily accessible when needed. Magnetic disk, magnetic tape and optical disk are used as the mass storage devices. The storage capacity of computer is measured in terms of kilobyte (KB), megabyte(MB), gigabyte(GB)

and terabyte(TB)etc. The smallest unit is bit, and the unit of 8 bits, is 1 byte.

Automatic

Computer is an automatic machine, capable of functioning automatically, once the appropriate set of instructions and data are provided to the computer. A computer an automatic machine and performs the work without intervention of user. User is required to give the data and utilize the result but the processing is automatic.