A bus is a set of wires. The elements of the computer are linked to the buses. It can transfer data from one element to another, the source element outputs data onto the bus. The destination element then inputs this information from the bus. As the complexity of a computer system improves, it becomes more effective (in methods of minimizing connections) at using buses instead of a direct connection between each pair of devices.Buses use less area on a circuit board and need less power than a huge number of direct connections. It can also need fewer pins on the ... Read More

The optical disk storage system includes a rotating disk coated with a diminished layer of metal that facilitates a reflective surface and a laser beam, which is used as a read/write head for recording information onto the disk. Unlike magnetic disk, the optical layer consists of a single long track in the form of a spiral shape. The spiral shape of the track produces the optical disk applicable for reading huge blocks of sequential information onto it, including music.Types of Optical DisksThere are two types of optical disks which are as follows −Compact Disk (CD) − The terminology CD used ... Read More

Magnetic tape transport includes the robotic, mechanical, and electronic components to support the methods and control structure for a magnetic tape unit. The tape is a layer of plastic coated with a magnetic documentation medium.Magnetic tapes are used in most organizations to save data files. Magnetic tapes use a read-write mechanism. The read-write mechanism defines writing data on or reading data from a magnetic tape. The tapes sequentially save the data manner. In this sequential processing, the device should start searching at the starting and check each record until the desired information is available.Magnetic tape is the low-cost average for ... Read More

A magnetic disk is a storage device that can be assumed as the shape of a Gramophone record. This disk is coated on both sides with a thin film of Magnetic material. This magnetic material has the property that it can store either ‘1’ or ‘0] permanently. The magnetic material has square loop hysteresis (curve) which can remain in one out of two possible directions which correspond to binary ‘1’ or ‘0’. Bits are saved in the magnetized surface in marks along concentric circles known as tracks. The tracks are frequently divided into areas known as sectors.In this system, the ... Read More

In a multiprogramming system, the main memory is broken into two parts as one part for the operating system (resident monitor) ad one part for the program currently being implemented. In a multiprogramming system, the “user” part of memory is divided to contain various processes. The task of the subdivision is carried out dynamically by the operating framework and is called memory management.Address spaces − The Pentium-II contains hardware for both segmentation and paging. Both mechanisms can be disabled, enabling the user to select from the definite aspect of memory −Unsegmented unpaged memory − In this case, the virtual address ... Read More

LatchA latch is a device with particularly two stable states and these states are high-output and low-output. A latch has a feedback direction, to maintain the data. Latches can be memory devices and can save one bit of information. It is used to “latch onto” data and save it in the required area. One of the most generally used latches is the SR latch.An SR latch is an asynchronous device. An SR latch does not rely upon control signals but relies only on the state of the S and R inputs. An SR latch can be generated by interlinking two ... Read More

Classic mask-programmed ROM chips are joined circuits that physically encode the information to be saved, and therefore it is inaccessible to modify their contents after fabrication. Several methods of non-volatile solid-state memory allow some degree of modification −Programmable read-only memory (PROM) − It is a one-time programmable ROM (OTP) and can be written to or programmed through a unique device known as a PROM programmer. This device uses high voltages to permanently damage or generate internal connections (fuses or anti-fuses) inside the chip.Erasable Programmable read-only memory (EPROM) − It can be erased by hazard to powerful ultraviolet light (generally for ... Read More

RAM is an element of the main memory that is directly usable by the CPU (Central Processing Unit). Memory can save programs and information during computer operations. The major technology used for the main memory depends on semiconductor integrated circuits.The feature of RAM is that it is volatile. A RAM should be supported with a fixed power supply. If the power is disrupted, therefore the data is hidden. Therefore, RAM can be used only as temporary storage. RAM technology has been divided into technologies which are as follows −Static RAM − Memories that include circuits that are adequate for maintaining ... Read More

Convex was the first device produce to commercialize a CC-NUMA machine, known as the SPP1000. SPP represents a Scalable Parallel Processor. The goals of the SPP Exemplar series are to make a family of high-implementation computers where the multiple processors can simply range from 10 to 1000 and the peak implementation would arrive at the TeraFLOPS.The node of the SP1000 is symmetric multiprocessors, called hyper nodes. Each hypernode includes four functional blocks and an I/O subsystem. Each functional block includes two CPUs (HP PA-RISCs) sending an individual CPU agent, and a memory unit influencing hypernode private memory data, global memory ... Read More

The Wisconsin multicube architecture employs row and column buses constructing a two-dimensional grid structure as shown in the figure. The three-dimensional generalization will appear in a cube structure.It can describe the cache coherence protocol of the Wisconsin multicube architecture, the following definitions must be given −Possible state of blocks in memoriesUnmodified − The value in the main memory is correct and it can have several correct cache copies.Modified − The value in the main memory is stale and there exists exactly one correct cache copy.Possible state of blocks in cachesData blocks in a particular cache can have three different local ... Read More