Niraj Tutorials

Mouse Mouse is a device that controls the movement of curser or pointer on a display screen.       A mouse is a small object, you can scroll along hard flat surface . It's name is derived from its shape. The mouse is important for graphical user can simply point to option click a mouse bottom. Scanner The keyboard can input only text thought keys provided in it. If we want to input a picture the keyboard cannot help us. Scanner is an optical device that can input any graphics chart or picture get it. Light Pen Light pen is a input device that is used hand in hand with the computer monitor it is called a light pen because its action is activated by light. It is important note cannot work with LCD (Liquid Crystal Display) screen, only work with traditional monitor CRT (Cathode Ray Tube).

Keyboard     Keyboard is an input device consisting a set of type writer like keys that enable you to enter data into your computer. It is a typewriter-style device. These are the most common and very popular input device. It help us input data to the computer/desktop. The layout of the keyboards is like that of traditional typewriter. There are 5 pare of a keyboard. Typing Keys Function Keys Control Keys Number Keys Special Purpose Keys Typing Keys The typing keys include the letter keys ( A-Z ) and digit keys ( 0-9 ) which generally give the same layout as typewriters. Function Keys The twelve function keys are present on the keyboard which are arranged in a line at the top ( F1, F2, F3, F4, .. F11, F12 ).

Floppy Disk Floppy disk is slower to access than hard disk. Floppy disk has low storage capacity, if the size of file increases than decreases the capacity of floppy disk. Hard Disk A Hard Disk is a storage medium. This drive is made up of a series of circular disk called platters arranged. A Hard Disk drive are made of non-magnetic material. A Hard Disk composed of numerous discs of metered sensitive to magnetic field. It has magnetic technology. Optical Disk An Optical Disk is input and output device. These devices use lesser technology to record data and information. It has a large storage capacity of the Gigabyte (GB). Magnetic Tape Magnetic Tape is a storage medium of secondary memory. They fit up to more than 4GB (Gigabyte). Pen Drive A Pen Drive is a portable memory devices. It is used to solid state memory rather t

ROM A computer memory on which data has been pre-recorded. Once data has been written on to a ROM chip. It cannot be removed and can only be read. ROM reads it contents when the computer is turned Off. This type of memory is non-volatile. The data and information is stored permanently in such memories during Manufacture. RAM chips are not only used in a computer but also used in other Electronic items as like washing Machine, microwave,..etc. Advantage of ROM Non-volatile Easy to text More reliable than RAMs Cannot be accidentally charged Cheaper than RAM Static and don't require refreshing There are three types of ROM. PROM EPROM EEPROM PROM A PROM is a memory chip on which data can be written on to a PROM, PROM written there contents when the computer is turned off. To write data on to a memory chip we need a special device called PROM programmer / PRO

RAM This is same as the main memory which used by it self. The Random Access Memory reference to read and write that is read, most RAM is volatile which means that it required to flow of electricity to means as soon as the power is turned off whatever data was in RAM his lost. RAM is volatile. As soon as the machine is switched off, data and information is erased. There are two types of RAM. SRAM (Static Random Access Memory) DRAM (Dynamic Random Access Memory) SRAM (Static RAM) Static Random Access Memory (SRAM) is a type of RAM that holds data and information in a static form. State RAM chips use a matrix of 6-transistors and no-capacitors. SRAM is thus used as Cache Memory and has fast access. Character of Static RAM (SRAM) Long data life Expensive Faster Cache Memory Low power consumption No need to refresh Large size DRAM (Dynamic RAM) Dyn

Memory Memory of Computer       Memory is a parts of computer that holds processing data and Information. The memory is the storage place in the computer, where data is processed and instruction required for processing are stored. The memory is divided into large number of small parts is called cell. There are two types of memory. Primary Memory Secondary Memory Primary Memory The primary memory stores data temporary and permanently. Primary memory is generally made up of semiconductor device. The data and instruction required to processed reside in the main memory. It is known as internal memory of computer. It is known as main memory. It is faster than secondry memory. It has limited capacity of data. Computer cannot run without primary memory. This memories are not as fast as registers. It is lost of data when the power is switch off. There are two types of Primary Memory.

CPU (Central Processing Unit) The part of computer that executes programs. In structures is known as the processer or the Central Processing Unit (CPU). In a computer the CPU is on a single electronic component in the system cabinet. CPU is the brain of computer. It perform all type of data processing operations. It control the operation of all parts in the computer. The CPU has three parts. Control Unit (CU) Arithmetic Logic Unit (ALU) Memory Unit (MU) Control Unit (CU) The control unit tells the rest of computer how to carry out programs introduction. It direct the movement of single electronics signals between Memory and ALU. It manages and co-ordinates from the memory. It communicate with input devices and output devices for transfer of data or results from storage. Control unit does not process or store data and responsible for controlling the transfe

Data Measurement Units Measuring Units 1 Nibble    =    4 Bites    =     1 Character 1024 Bytes =  1 Kilobyte (KB) 1024 Kilobyte =  1 Megabyte (MB) 1024 Megabyte =  1 Gigabyte (GB) 1024 Gigabyte =  1 Terabyte (TB) 1024 Terabyte =  1 Petabyte (PB) 1024 Petabyte =  1 Exabyte (EB) 1024 Exabyte =  1 Zettabyte (ZB) 1024 Zettabyte =  1 Yottabyte (YB) 1024 Yottabyte =  1 Brontobyte (BB)

Computer         Computer is an electronic machine which can calculate large type of data without any mistake and high speed. It has the ability to retrieve, store data and process data information. We probably already know that we can use a computer to type document, playing games, send email, and browse the web. We can also use a computer to edit or create documents, spreadsheets, presentations, photos, videos, etc. Advantages of a computer Computer is a very fast device. It is calculate very large amount of data. It perform all with 100% accuracy provided that the input is correct. A computer can store large amount of data as like images, videos, documents, text, audio, etc. It can work continuously without any mistake and boredom. It is very flexible in performing the jobs and solve the problems related to various fields. A computer is an automatic and reliable machine. Disadvantage of a computer A computer is a machi