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Showing posts from May, 2019

Input Devices

Input Devices(इनपुट डिवाइस ) Input device enables the user to send data, information or control signals to computer. Central processing unit of computer receives the input and processes it to produce output. Some of the popular input devices are: Keyboard Mouse Scanner Joystick Light Pen Track ball Digitizer Microphone Magnetic Ink Character Recognition (MICR) Optical Character Reader (OCR) Keyboard (कीबोर्ड ) It is a basic input device that is used to enter data by pressing keys. It has different sets of keys for letters, numbers, characters and functions. QWERTY keyboard is the commonly used keyboard to enter data. Mouse (माउस) It is a hand held input device. It is used to move cursor or pointer across the screen. It generally has left and right button and a scroll wheel between them. Laptop computers come with a touch pad that works as a mouse. It lets you control the movement of cursor or pointer by moving your finger over the touchpad. Scanner (...

Types of computer

Types of Computer (कंप्यूटर के प्रकार ) We can categorize computer by two ways: data handling capabilities and size. On the basis of data handling capabilities , the computer is of  three  types: Analogue Computer (एनालॉग  कंप्यूटर ) Digital Computer (डिजिटल कंप्यूटर ) Hybrid Computer (हाइब्रिड कंप्यूटर ) 1) Analogue Computer(एनालॉग  कंप्यूटर ) Analog computers are designed to process analogue data. Analogue data is continuous data that changes continuously and cannot have discrete values such as speed, temperature, pressure and current. The analogue computers measure the continuous changes in physical quantity and generally render output as a reading on a dial or scale. Analogue computers directly accept the data from the measuring device without first converting it into numbers and codes. Speedometer and mercury thermometer are examples of analogue computers. 2) Digital Computer(डिजिटल कंप्यूटर) A digital computer is designed to perfor...

History of Computers

Hello Students For Class XI(OSVN Inter College) History of Computers The first counting device was used by the primitive people. They used sticks, stones and bones as counting tools. As human mind and technology improved with time more computing devices were developed. Some of the popular computing devices starting with the first to recent ones are described below; Abacus The history of computer begins with the birth of abacus which is believed to be the first computer. It is said that Chinese invented Abacus around 4,000 years ago. It was a wooden rack which has metal rods with beads mounted on them.  The beads were moved by the abacus operator according to some rules to perform arithmetic calculations. Abacus is still used in some countries like China, Russia and Japan. An image of this tool is shown below; Napier's Bones It was a manually-operated calculating device which was invented by John Napier (1550-1617) of Merchiston. In this calculating t...