What is Memory?

-
It is the computer's workspace (physically, a collection of RAM chips). It is an important resource, since it determines the size and number of programs that can be run at the same time, as well as the amount of data that can be processed instantly. All program execution and data processing takes place in memory. The program's instructions are copied into memory from disk or tape and then extracted from memory into the control unit circuit for analysis and execution. The instructions direct the computer to input data into memory from a keyboard, disk, tape or communication channel. As data is entered into memory, the previous contents of that space are lost. Once the data is in memory, it can be processed (calculated, compared and copied). The results are sent to a screen, printer, disk, tape or communication channel. The size of memory is measured by the number of bytes available for use. A kilobyte of memory, abbreviated KB or K, is equal to exactly 1,024 bytes. To make storage definitions easier to identify, computer users often round a kilobyte down to 1,000 bytes. For example, ii a memory chip can store 100 KB, it is said to hold 100,000 bytes (characters). A megabyte, abbreviated MB, is equal to approximately as one million bytes. Memory are of two types :
•RAM= RAM stands for read only memory. RAM functions as a scratch pad for the computer and is sometimes called the scratch pad memory.

•ROM= The ROM contains permanently recorded instructions that are vital for starting up a computer. One set of instruction found in ROM is called ROM-BIOS, that stands for read-only memory. Any set of programs residing in ROM is called firmware.

Comments

Post a Comment

Popular Posts

What is a Geostationary Orbit?

-
Image
Artificial satellites sent from the Earth orbit around the earth. The ones near the Earth orbit faster than the ones far away. A satellite 35,900 Km above the Earth's surface, takes 24 hours to orbit once. The satellite is always above the same point on the Earth's surface as the planet rotates. Geostationary orbit is also called as geosynchronous ' orbit. Such satellites are used to receive telephone and television signals and retransmit them over long distances.
Read more

When were the First Spinning Machines Invented?

-
Image
People in the olden days used to spin thread by hand . They pulled fibres out of cotton and wool and twisted them together into thread. Spinning machines were invented in Britain in the 1700s. These machines had rollers turning at different speeds to twist the fibres into yarn. James Hargreaves in 1764 produced the first successful spinning machine. It was the hand-powered jenny which produced thin yarn. Richard Arkwright's water frame of 1769, powered by water wheels, gave a sturdy thread. Samuel Crompton combined these two spinning machines in 1779 , to make the spinning mule, which could spin many kinds of yarn. These machines were the precursors of the Industrial Revolution . 
Read more

Why is Venus so Hot?

-
Image
T he planet Venus is named after the Roman goddess of beauty and love. It is the brightest planet in the Solar System. It is visible as a star. Venus is much hotter, because it is much closer to the Sun. The atmosphere there is 90 times thicker than that of the Earth and the surface is hidden in a white cloudy cloak. This thick atmosphere acts like a blanket which holds back the heat of the Sun and turns the midday temperature to 4800C. The atmosphere on Venus consists mainly of the carbon dioxide gas which acts as a greenhouse roof , trapping the Sun's heat. The rocks on Venus are hotter than boiling water. Above the rocks, winds blow at a speed of 320 km/hour .
Read more

What is a Mouse?

-
Image
An input device that is used to point and select an option on the VDU is called a mouse. The basic features of a mouse are a flat-bottomed casing designed for gripping by one hand ; one or more buttons on the top; a multidirectional detection device (usually a ball) on the bottom; and a cable connecting the mouse to the computer. By moving the mouse on a surface (such as a desk top), the user typically controls an on-screen cursor . The user presses one of the mouse's buttons, producing a 'mouse click‘ to select items or choose commands.
Read more

When were the First Mechanical Clocks Made?

-
Image
The first mechanical clocks are believed to have been made in China in 1088 AD. Later in 1200s, they were first made in Europe. Such clocks made in Europe were driven by a weight on the end of a cord wound round a drum. As the drum rotated, it turned the hands of the clock. The earliest known clock was made in Spain in 1276 AD and the oldest mechanical clock that still works is in Salisbury cathedral in Britain. It was made in 1368. These clocks had devices called escapements to keep the hands turning at the correct rate, so that the clocks depicted the correct time.
Read more