Found 691 Articles for Computer Science

The hot standby mode is a fail-safe in which a hot standby component is part of an active system. If any component of the system fails, the hot standby component takes its place. In general, a hot standby can refer to any device, system etc. that overtakes operation from a failed device and reduces the startup delay that would otherwise be huge.A figure to further explain the hot standby mode is as follows −In general, it is expected that a system will have some failures. So, a hot standby is necessary to combat these failures.At the extreme, a hot standby ... Read More

Cache is a type of memory that is used to increase the speed of data access. Normally, the data required for any process resides in the main memory. However, it is transferred to the cache memory temporarily if it is used frequently enough.A diagram to better understand the data transfer in cache management is as follows −Cache PerformanceThe cache performance can be explained using the following steps −If a process needs some data, it first searches in the cache memory. If the data is available in the cache, this is termed as a cache hit and the data is accessed ... Read More

Memory management plays an important part in operating system. It deals with memory and the moving of processes from disk to primary memory for execution and back again. Some basic concepts related to memory management are as follows −Virtual Address Space and Physical Address SpaceThe address generated by the CPU is known as the virtual address and the address seen by the memory is known as the physical address. In compile time and load time address binding schemes, both the virtual and physical address are the same. They differ only in the execution time address binding scheme.All the logical addresses ... Read More

A distributed system contains multiple nodes that are physically separate but linked together using the network. All the nodes in this system communicate with each other and handle processes in tandem. Each of these nodes contains a small part of the distributed operating system software.A diagram to better explain the distributed system is −Types of Distributed SystemsThe nodes in the distributed systems can be arranged in the form of client/server systems or peer to peer systems. Details about these are as follows −Client/Server SystemsIn client server systems, the client requests a resource and the server provides that resource. A server ... Read More

Dynamic RAM (DRAM) is a type of semiconductor memory that uses capacitors to store the bits. The charging and discharging of the capacitor represents 0 and 1 i.e. the two possible values that can be stored in a bit.The DRAM is a volatile memory i.e. the data in memory is lost when power is switched off. However, it still displays some data remanence. DRAM is low cost compared to SRAM so it is primarily used in main memory.The following displays a DRAM:Versions of DRAMAsynchronous DRAMThis was the first type of DRAM in use but was gradually replaced by synchronous DRAM. ... Read More

Random access memory (RAM) is a type of primary storage. It allows the user to randomly access any part of the data regardless of its position in roughly the same time. This is not possible using other storage devices such as hard disks, CD’s etc. because they have physical constraints such rotation speeds, arm movements etc.RAM is mostly volatile i.e. the data in RAM is dependent on the power and as lost when power is switched off. However, there are some non - volatile versions of RAM also available.There are mainly two types of RAM available i.e. Static RAM (SRAM) ... Read More

Computer storage has components that store computer data. The different storage types in the storage hierarchy are as follows: Primary Storage This is also known as the main memory and is the memory directly accessible by the CPU. All the instructions are executed in the main memory by CPU and the data required by these instructions is also stored in main memory. Main memory primarily consists of the RAM which is volatile in nature. It is also quite small compared to secondary memory and expensive as well. Secondary Storage Secondary or external storage is not directly accessible by the ... Read More

Computer storage contains many components that are used to store computer data. Some information about the various storage devices is given below.Computer Storage DefinitionsThe computer storage devices include Primary and Secondary Storage devices. These are explained in detail as follows −Primary Storage DevicesPrimary storage is also known as the main memory and is the memory directly accessible by the CPU. Some primary storage devices are −ROMROM is read only memory. This memory cannot be changed, it can only be read as required. Since ROM is unchangeable memory, it is used by data and programs that are frequently required and seldom ... Read More

The computer system is a combination of many parts such as peripheral devices, secondary memory, CPU, etc. This can be explained more clearly using a diagram.The salient points about the above figure displaying Computer System Organisation is −The I/O devices and the CPU both execute concurrently. Some of the processes are scheduled for the CPU and at the same time, some are undergoing input/output operations.There are multiple device controllers, each in charge of a particular device such as keyboard, mouse, printer etc.There is buffer available for each of the devices. The input and output data can be stored in these ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.The place of an operating system in a computer can be demonstrated aptly using the following diagram:As can be seen from the above diagram, the computer system is divided into four components namely, hardware, operating system, application programs and users.The operating system coordinates between the hardware and the application programs. It makes sure that adequate hardware resources are distributed ... Read More