Computer Peripheral Architecture - Essay Example

A Report on Computer Peripheral Architecture 5th December, 2009 This report will discuss the various peripherals being used in virtual environments. There are three main areas are to be researched into, which are Data storage and representation, Environment manipulation, and Communication. These days, a lot of new peripherals are being introduced which run at greater speeds. Thus there is the need for more interactivity for applications. Most interface are also becoming smaller and more of them are now wireless equipped Data storage and representation The computing industry has a definition of primary and secondary storage that refers only to secondary storage. In this definition, primary devices refer to the computer's main storage device, such as an IDE or SCSI hard drive. Secondary devices, under this definition, are any non-primary storage device, such as a tape drive, writeable CD-ROMs or removable flash drives. Each type of storage media has different applications. Hard drives are the best choice for large volume, primary data storage. Regardless of the hard drive technology, the hard drive sacrifices speed for storage capacity and density when compared to volatile storage devices such as RAM (Random Access Memory) . RAM, on the other hand, is not typically used for file system data storage because of its non-permanent nature. Due to its high-speed connection to the computer's CPU, RAM makes the best choice for primary storage. RAM typically can store and retrieve data at speeds that exceed 4 to 5 times that of the fastest hard drives. Writeable CD-ROM media, tape drives and flash drives make good choices for secondary storage devices (using either definition). These devices are often removable and, with the exception of magnetic tapes, offer higher reliability than hard drives that are dependent on moving parts. Computer users often depend on these devices to store backup or archive information, or to carry data that must be easily portable from site-to-site. "A character file may be transferred to a host for one of three purposes: for printing, for storage and later retrieval, or for processing. If a file is sent for printing, the receiving host must know how the vertical format control is represented. In the second case, it must be possible to store a file at a host and then retrieve it later in exactly the same form. Finally, it should be possible to move a file from one host to another and process the file at the second host without undue trouble. A single ASCII or EBCDIC format does not satisfy all these conditions." (DATA REPRESENTATION AND STORAGE) Flash drives, tapes or Zip disks. Unlike secondary storage, primary storage is volatile and all primary storage information is lost when the computer is powered down. Secondary storage devices are non-volatile and store information not currently being processed by the computer. Secondary storage devices do not lose information when the device is not powered. The real world objects that are included must be represented by an object defined in the GISystem software. For example, a road network of a town comprises the road surfaces, footpaths, kerbing (and other structures). In a GISystem it will usually be represented by a network of lines defining the centre lines of the roads. In a raster model GISystem, a connected series of cells (rather than a line) would represent a road. The objects that are represented in a GISystem will have defined boundaries. Real world features like forests or soil parcels, do not have sharp boundaries in the real world, however in a GISystem, they will be assigned boundaries. The likely uses of the data will again be decisive in determining the form of representation. At small scales, roads are usually represented by line networks defining the centre lines of the roads. For engineering uses, larger scales are employed, and the objects represented will include the kerbing and footpaths, the exact shapes of the curves, etc., but not just single lines. Thus, representation depends on usage, which also effects scale. "Data is transferred from a storage device in the sending host to a storage device in the receiving host. Often it is necessary to perform certain transformations on the data because data storage representations in the two systems are different." (DATA REPRESENTATION AND STORAGE) What extra data will be required to be generated by the application to service these new devices Like data storage, the computer industry uses several different definitions of "speed" when discussing computer performance. The theoretical "speed" of a computer, in purely technical terms, is defined by the actual clock rate of the various components: CPU speed, bus/switch backplane bandwidth and speed, memory bus speeds, hard drives. Most users define "speed" by measuring application performance or usability under normal conditions. Viewed from a technical standpoint, the type of RAM (registered, unregistered, DDR, SDRAM, etc.), the size of level 1 and level 2 cache on the CPU and the memory bus speed dictate the actual speed. The amount of RAM does not affect speed. However, from a usability standpoint, users will commonly report an increase in "speed" when they install additional RAM. In this case, users are more properly reporting usability or performance and not actual differences in speed. The clock speed of a CPU, memory bus, PCI bus, switch fabric directly impacts the speed of a computer in both technical terms and in terms of user perceptions. Differences between architectures and combinations of various components obviously have a significant impact that is beyond the scope of discussion in this paper. Barring performance bottlenecks caused by capacity issues, when all other things are held equal, a faster clock rate indicates faster "speed" both technically and in terms of usability. In reality, the clock speeds of various components do not operate in a vacuum and the clock speed alone does not indicate the overall speed of the computer. The storage of data on various types of media (hard drives, CD-ROM, floppy, flash, etc.) does not affect the actual speed of a computer. However, the various media will often create differences in a user's perception of a computer's "speed." In today's computers, hard drives typically offer the fastest access to data when all other things are held equal. CD-ROMs, while faster than ever before, typically perform more slowly than hard drives or flash-based media. Media that offers faster access to stored data will result in a user's perception of a "faster" computer. The speed increase also depends on the type of hard drive, CD-ROM or flash drive technology used in the computer. For example, hard drives generally rely on one of five major technologies: IDE, SCSI, Serial ATA, fiber channel or SCA. Each offer advantages and disadvantages and differences in speed. Individual drives differ in speed as well, based on drive size, number of platters and variables. Today's business and home consumer has a range of input and output devices and computer hardware available. Each device and type of hardware offers distinct advantages in accuracy, convenience, quality and performance. Users must carefully select the proper technology for their needs and understand the underlying components that determine the speed and usability of their computing platforms. Environment manipulation When providing feedback to the user, for example, the force feedback systems used for joysticks and steering wheels, binary data stored in ram can be used to generate the analogue physical feedback for the user. A simple circuit diagram of this process is depicted below Communication A lot of devices used in the manipulation of software are knowable to provide feedback to the user. Thus, a user can experience virtual environments that match more of our senses. These senses including touch, hearing, temperature, sight and even smell. i. Data rates The characteristics of the transmission facilities lead to an emphasis on efficiency of communications techniques in the design of WANs. Controlling the volume of traffic and avoiding excessive delays is important. Since the topologies of WANs are likely to be more complex than those of LAN (Local Area Network), routing algorithms also receive more emphasis. WAN is used across a state and country or even around the global. Many LANs are connected to each others using WAN communications under a high speed communication. Bridges, routers and multiplexers and other devices are used for correct data transmission. The technology in this field continues to evolve rapidly manufacturers of wireless systems continue to develop new and faster products. Wireless benefits offer flexibility, and mobility with low long-term costs. The data rates are slower that wired networks, but the gap is closing. It is up to the enterprise to justify which WLAN to choose one that is of most value to them as they offer benefits in different areas i.e. higher data transfer verses range of transmission. iii. Buffer sizes A buffer is a memory section that can be used for temporary storage of data. The buffer size in a drive, which is also known as the cache size, represents the amount of data that can be stored inside it, while preparing to burn the information onto a CD or DVD. If there is need to write data to a CD or DVD, it is advisable to avoid writing the data directly from the hard disk. The Data should be written at a rate that is constant, so writing directly from the hard drive is not advisable, as the speed of the process from a hard disk can fluctuate. Thus, the data should first be copied into a buffer. The buffer size is normally 256K in size. "If the rate at which data is read off the buffer is faster than the rate at which data comes into the buffer, a buffer underrun may occur where there is no data left to read. This causes a problem for recording discs, as once the laser is on it cannot stop and resume flawlessly. If the buffer underruns then the laser has to pause, and this may cause the data on the disc to become invalid and make the disc unusable. This was a major problem with CD burning in the early 1990s, but various buffer underrun protection methods have now been implemented in drives." (http://www.misco.co.uk/content/MODULE/REMOVABLESTORAGE/WHAT-IS-BUFFER-SIZE.HTMbp=1) The easiest way to prevent buffer under-run is by increasing the buffer size. DVD burners usually have buffer size of about 2 MB, although in some models, buffer size may be as high as 8 MB. A bigger buffer size allows longer interruptions in the flow of the data from the hard disk to happen, while preventing an under-run. Have a larger buffer size cannot handle every problem in the flow of data however, and there may still be buffer under-run if the rate into the buffer slows down too much. Thus, a lot of CD writing software can monitor the buffer and decrease the speed of the recorder when necessary. If that fails, there are still a lot of hardware that are now able to resume the CD burning process even if when there is a buffer under-run. Combining a hard drive with a high data transfer rate and a burner with a large buffer size can also help to avoid too much slowing down the rate of recording when burning data onto a large number of discs. Works Cited Berry, L., Parasuraman, A. and Zeithaml, V. (1994) Improving Service Quality in America: Lessons Learned. The Academy of Management Executive, 8, 32-52 Nickerson, R. (2001). Business and Information Systems, Second Edition Upper Saddle River, NJ: Prentice Hall. Federal Reserve System (2004). Fedpoint: Float. Retrieved December 5, 2004 from http://www.ny.frb.org/aboutthefed/fedpoint/fed08.html DATA REPRESENTATION AND STORAGE. Retrieved from http://www.freesoft.org/CIE/RFC/959/7.htm http://www.misco.co.uk/content/MODULE/REMOVABLESTORAGE/WHAT-IS-BUFFER-SIZE.HTMbp=1 Read More