Computer Systems Essay

Explain the function of the system unit components and how they communicate Central processing unit – The Central Processing Unit (CPU) carries out the actual processing of data. The data it processes is gathered via the system bus, from the main memory. The CPU then sends back the results to main memory via the system bus. The CPU also controls and times the operations of the other key components. CPU’s use in their operation: Fetch, decode, execute, and writeback. BIOS – The BIOS is a built-in software that decides what a computer can do without having access to a hard drive or CD/DVD. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of other miscellaneous functions. Motherboard – The motherboard is a printed circuit board (PCB) that houses and controls the components that are in charge of processing data. A motherboard provides the electrical circuit connections, these circuits are used by other components of the system to communicate. The central processing unit and other subsystems such as real time clock, and various peripheral interfaces are also located on the motherboard. This is motherboard doesn’t use active heat sinks on its bridges instead it uses a complex passive heat sink. Power Supply – A power supply unit (PSU) is the component that supplies power to a computer. In a PC the power supply is the metal box usually found in a corner of the case. The power supply has many various power leads all for different things such as: * 20+4pin power connector o Powers the motherboard, depending on what motherboard you have it will either require a 20pin or a 24pin connector. * 4+4pin ATX 12V Connector o Powers the CPU, depending on what motherboard you have it will either require a 4pin or a 8pin connector * 6pin PCI-E VGA card Connectors o Power modern graphics cards, depending on the graphics card it will either require 1 or 2 6pin connectors. * SATA Connectors o Used for most internal components such as SATA hard drives and SATA optical drives. * 4pin peripheral Molex Connectors o Molex connectors are used for fans, lights and various other internal components. * Floppy connectors o Used to connect floppy disk drives. Heat Sink & Fan – A heat sink is specifically designed to reduce the temperature of an electronic device by releasing the heat into the surrounding air (case fans would then push out this hot air while pulling in cool air). All modern CPUs need a heat sink and most heat sinks require a fan. A heat sink without a fan is called a passive heat sink; a heat sink with a fan is called an active heat sink. Heat sinks are generally made of an aluminium alloy. This picture shows various heat sinks used for devices like the CPU, graphics card, bridges on a motherboard and much more. Depending on how hot a device gets an extra fan may be required, the CPU, graphics card and motherboard all tend to use active heat sinks. Hard Disk Drive – The hard disk drive is non volatile memory storage that uses a mechanism to read and write data on a hard disk. Every modern computer contains one or more hard disks. The purpose of the hard disk drives is that they give computers the ability to remember things when the power goes out. A typical modern desktop machine will have a hard disk with a capacity of between 250GB and 1TB. Data is stored onto the disk in the form of files. The master (typically C:) is the primary drive, which the computer uses to boot up, the slave (D:) is usually used for extra storage and buck ups. Integrated Drive Electronics (IDE) – Floppy drive, hard drive and the CD-ROM drive are all connect to the computer through an Integrated Drive Electronics (IDE) interface. An IDE interface is a standard way for a storage device to connect to a computer. Serial Advanced Technology Attachment (SATA) – Is a computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives. SATA speeds are far greater than IDE and the size difference means they are easier to manage and don’t restrict air flow, so most modern computers tend to use SATA over IDE. The size difference between IDE (left) and SATA (right). Describe the purpose, features and functions of two different operating systems. Windows 7 Features Feature Description Useful? #1 Snap Snap lets you drag one window to the left and one to the right, allowing you to see two windows side by side. Very much, I think this feature alone makes Windows 7 stand above the rest. #2 Taskbar A remake of the old taskbar that introduced some new features such as pinning, this allows you to pin a application to the taskbar (similar to Mac dock) Again this is a very useful feature, you can pin as many applications to the taskbar as you wish. #3 Thumbnail Previews Exactly what it sounds like, thumbnail previews allow you to preview a window that is minimised or behind another window, it is also the new way to group similar windows. This feature is helpful if you have multiple similar windows open however if you just have one or two windows open its not so great #4 Jump List Jump list lets you access your recently used files, depending on the application you can see your most played music (media player) or recently opened documents. Handy for some applications although not a key feature in my opinion. #5 Aero peek This feature allows you to make all open windows transparent this lets you view your desktop without minimising all your windows. This is another feature I love, I tend to save quite a lot of downloads to my desktop and being able to flick back and forth without minimising is great. #1 Snap #2 Taskbar #3 Thumbnail Previews #4 Jump List #5 Aero Peek Undertake routine maintenance tasks in relation to a PC. I will show you how to carry out several forms of maintenance, software, hardware and file management. Software maintenance To demonstrate software maintenance I’m going to update my antivirus. To start the process you first need to load up your antivirus (I’m using NOD32). Once the main antivirus window is open I need to navigate to the update option. Fortunately my antivirus does not need updating as my current virus signature database is up to date . This is what happens when it’s not up to date, after a speedy download it will take me to the previous page and let me know if it’s up to date. Hardware maintenance. To demonstrate hardware maintenance I’m going to find and use a printer that is connected to a separate computer on my network. How I installed the printer on the other machine. Installation was simple and fast, all I needed to do was connect the printer to the computer via USB and plug in the power lead. After turning on the printer I turned on the computer, then I installed the drivers and relevant software from the CD. After a quick reboot I printed a test page and it worked fine. Finding the network printer. To start the process I went to Start > Control Panel > Hardware and Sound > Devices and Printers > Add a printer. Decide what type of printer you are trying to find, because the printer i intend to use runs through another computer i need to select Add a network, wireless or Bluetooth printer. Hit Next and allow it to search, once the results are displayed select the printer you wish to use. You should get a quick window showing you its being connected. You should get a window telling you everything was successful. Followed by the option to print a test page. File management. To demonstrate file management I’m going to show a simple way to manage your files. Sometimes folders and files get in the wrong place and things start to get lost and missing files get accidently deleted. Make sure you delete useless and old files to free up hard disk space, do this by selecting the document and hitting delete or right clicking the file and selecting delete. After creating relevant folders and deleting unnecessary files the folder looks much more organised and manageable. Disk Cleanup Disk Cleanup is a maintenance utility bundled in with Microsoft Windows, its purpose is to free up disk space on the computer’s hard drive. Disk Cleanup first searches your hard drives for files that are no longer being used it then deletes these unnecessary files. As well as cleaning unused files Disk cleanup can also compress files that haven’t been used for a long period of time, this helps make space but if you wish to access files that have been compressed at a later data the loading times can be Disk Cleanup looks in various categories to target these files. * Downloaded Program files * Compression of old files * Temporary Internet files * Recycle Bin * Offline files * Removal of unused applications or optional Windows components * Setup Log files * Temporary Windows file These aren’t the only locations Disk Cleanup looks for files, some options only appear with certain computer configurations. There are also options to remove unused windows components to help free disk space. Quick example of how it works To start Disk Cleanup go to Start > Programs > Accessories > System Tools When the program launches it will begin analyzing how much space it will be able to free. The next step is selecting what you wish to clean, be careful you don’t delete things you need, saved passwords for internet website ect. The View Files button allows you to see the files that will be cleaned. After selecting what to clean you then run the programs, the progress bar shows you how long till its done. Antivirus Every computer that connects to the internet needs an antivirus program, an antivirus program is used to detect, prevent and remove computer viruses, Trojans horses, worms and in some cases spyware, adware and other malicious software. There are various strategies for detecting threats the most common is signature-based detection, this involves using a library of already known threats and searching for these patterns in executable code. Unfortunately some threats are too new to be in this library; in cases like this the antivirus attempts to compare code in its library with new threats. Quick example of how it works This depends on where you install your antivirus but they can be launched by going to Start > Programs > [Antivirus manufactures name] > [Antivirus program]. For this example ill be using my colleges antivirus, Sophos. When you launch the antivirus it will have several options, the first thing you need to do is to update the program, and it’s no good searching for viruses if you’re using and out of date database. After updating you need to scan for potential threats. The scan progress window will give you a rough idea of when it will finish as well as what’s being scanned and what infections have been found. After the scan is completed you should get some form of summary, this will tell you the amount of items scanned, infected items and items that have been place in quarantine. By quarantining threats it ensures your computer stays completely safe, some items are misread and are actually not harmful so quarantining these allows the user to tell the antivirus that they are safe before they get deleted. Available utility software Utility software allows a user to analyze, configure, optimize and maintain their computer and should ned be confused with application software, this type of software allows us to create text documents, listen to music, browse the internet and much more. Utility Description Disk Defragmenters Locates files that are broken over different locations then moves the fragments to the same location to increase efficiency. Disk Cleaners This disk utility is designed to free up disk space and a computer’s hard drive. It does this by searching and analysing the hard drive for files that are no longer of any use, it then removes the unnecessary files. Backup This involves making copies of important data so that these additional copies can be used to restore the original if it were lost or damaged. CLI and GUI CLI allows you to interact with a computer by typing commands in the text only interface. GUI is another way you can interact with a computer, instead of using a text interface it has a graphical interface that consists of icons. Registry Cleaners This utility was designed to remove registry entries that are no longer in use and are unwanted. Antivirus That is used to prevent and remove malware, including Worms, Trojan horses and computer viruses.