These ram chips may be placed on an add on circuit

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Unformatted text preview: rage. Moreover, to protect the data against natural calamities, it is suggest to store the backup media.with the backed up data in a building that is away from the building where the computer system whose data is backed up is located. RAM Disk We saw that hard disks are used as on-line secondary storage devices in most computer systems of today. However, the data access speed of a hard disk is much slower than that of a semiconductor RAM (recall that RAM chips are used for main memory). This is because hard disks involve mechanical movements, whereas semiconductor RAMs are pure electronic devices. To make applications execute faster, in some computer systems a block of semiconductor RAM chips (other than the RAM chips used for the main memory) is used as a simulated disk. That is, an application to be executed is first loaded from the hard disk into the simulated disk and then only its execution is started. The application executes faster than normal in this case because the method avoids most of the delay that might be caused by frequent calls to the hard disk for data loading during execution. The RAM chips used as a simulated disk are often referred to as a RAM disk, or a silicon disk, or a pseudo disk. These RAM chips may be placed on an add-on circuit board that fits inside the main computer box, or they may be housed in a separate cabinet. In either case, these extra RAM chips look just like a disk drive to the control programs used in the computer's operating system. Note that RAM disk is not really a disk at all. A RAM disk greatly helps in enhancing the speed of the computer system because the CPU can now access the desired data almost instantly from the RAM disk instead of waiting for few milliseconds to obtain the same data from the hard disk. However, RAM chips are volatile and the data stored in them are lost when power is switched off. Thus, programs and data files produced during a processing session must be stored on a permanent storage device, such as a hard disk...
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This document was uploaded on 04/07/2014.

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