Major Issues of a Computer System - Essay Example

?A computer may be defined as a high speed electronic device, which accepts raw data through an input device for processing in order to provide userswith information through an output device (Anderson 2001). Raw data may be in form of text, digits, graphics, voice etc while out put may be for example; printouts, softcopy display through the screen, sound etc. A computer system consists of three major entities, which must work together for there to be efficiency. These include; hardware, software and liveware. Hardware refers to all the tangible parts of a computer system such as keyboard, mouse, screen, among others while software refers to the programs that run in a computer such as application software, operating systems etc. On the other hand, liveware refers to the users i.e. human beings, who operate the systems by issuing commands to be executed by the system (Anderson 2001). However, for these users to be able to input data and commands, which instruct the system to perform various actions, there must be a way through which they can interact with the computer, which is commonly referred to as human computer interface (HCI) (Stephenson 2001). For example, if a user wants to open an already existing document, he must issue an ‘open’ command to the system through the computer interface available in his system. Currently, there are two major HCI i.e. command line (CLI) and the graphical user interfaces (GUI). Command line interfaces were the most widely used before technological advances in programming resulted to the designing of window based operating systems, which enabled users to interact with their computers through GUI. In a command driven interface, the user uses the keyboard to type commands, which are acceptable to the computer, after which the results are displayed on the screen in form of text. This type of interface came in to use in the early 1950s, an invention which was motivated by the introduction of teletypewriters, which demanded instant display of results (Stephenson 2001). Before this, batch interfaces were used, which are considered to have been non-interactive as they only required the user to input all the data in order for processing to begin, after which there was no opportunity for inputting more data until after all the data was processed and output was given (Stephenson 2001). The disc operating system (DOS) is one of the environments that make use of the command line interface. In order to be able to operate such an interface, it is a must for one to have excellent skills and understanding of the various internal and external commands, which follow predetermined syntaxes (Gookin 2004). For example, if a user intends to view files located in the hard drive i.e. the hard disk, he would have to type a command, which would order the system to display all the files as per the user’s request. The syntax in such a context would appear as follows; c:\dir after which you press enter to display the contents. To access a removable storage media named drive E, one has to type a special command designed for that purpose. This would appear as follows; c:\e: then press enter. C:\ in this case is the root directory, while e: is the destination drive. This implies that command driven interface is tedious to use as one must follow the exact syntax and path in order to get results, which may be the reason why it is widely used by programmers and other IT specialists, who are well conversant with the commands (Gookin 2004). The graphical user interface as opposed to command line interface uses images, which are event driven. This means that once the user clicks on the image, a predetermined action is triggered and as such, clicking becomes a command executor in contrary to CLI where one had to type a specific command on a command prompt (Anderson 2001). However, it is important to note that GUI enables the user to use both the keyboard and the mouse to execute commands. Images in this context are for example; radio buttons, windows, icons, menus among others, which are designed in a manner that enables a user to easily recognize their functions (Anderson 2001). The save icon for example, in most of the window based computer applications, is usually represented by a small picture of a diskette, which displays a ‘save’ message on mouse over. Several options are provided for performing the same action such as clicking on the file menu and clicking on the save or save as options, which then initiates a dialog box prompting the user to input file name and specify the storage location. This makes it easy and interesting for a person, not necessarily an expert, to operate a computer, which might be one of the major reasons why even young children are capable of accessing and utilizing this important communication resource. Graphical user interface is advantageous due to the fact that the user is enabled to view immediate results after a command is executed (Senn 2003). For example, movement of files from one location to the other can be achieved through the cut and paste commands. For this to happen, the user must be in the exact location where the file is in order to be able to cut it after which he would have to open the destination location where he is to paste it. Once pasting is done, the icon representing the file appears thereby indicating that the operation has been completed. On the contrary, command line interfaces do not offer this privilege to the users i.e. there is no automatic feedback to prove that the operation has been successful. Graphical user interfaces enable users to multitask. In this context, a user is facilitated with a windows environment where he can utilize the three major buttons i.e. minimize, maximize or restore, to switch between multiple windows. On the other hand, he can opt to utilize the task bar, which displays icons of the various documents or programs running concurrently. To activate a window, the user is only required to click on one of the icons on the task bar. This enhances productivity and efficiency as one person can serve numerous clients requiring information from different files stored in the computer (Senn 2003). In addition, GUI has made it possible to operate computer applications such as AutoCAD, PageMaker among others, which are used in graphic design (Senn 2003). In these applications, several buttons are used to represent the type of object the user intends to draw such as lines, text boxes, arrows, circles among others. Most importantly, it becomes easier to modify properties of these objects, for example width, height or even angles by rotating, which is conducted by dragging the mouse pointer over the object in the desired direction. Double clicking on the object also produces a dialog box, through which a user can define more properties such as line colour, background fill etc, thereby producing high quality outputs. These are operations which cannot be achieved through a command line interface. However, there are various shortcomings associated with GUI. For example, the ease of use makes it possible for other users to delete or modify important documents stored in a computer either accidentally or intentionally. This may be much more difficult in a command driven interface as such users must know the exact location of such files so as to be able to enter the correct syntax for such operations to occur (Stephenson 2000). This means that accidental deletion of files is next to impossible in such a circumstance. Similarly, hackers and crackers have utilized this interface to lure unsuspecting users into their traps. For example, a user accessing the internet may encounter pop up menus, which are usually designed in a manner that once the user clicks on them, a channel is created for computer viruses to enter and attack the computer. Such menus may display messages such as those informing the user that he or she has won certain amounts of money and therefore they have to click on a certain button so as to access more information. This has also been used to commit identity theft, which continues to facilitate criminals with a channel to commit credit card frauds (Senn 2003). Bibliography Anderson, A. (2001) Foundations of Computer Technology, CRC Press Gookin, D. (2004) DOS for Dummies, IDG Books Senn, J. (2003) Information Technology: Principles, Practices, and Opportunities, Prentice Hall Stephenson, L. (2000) In the Beginning...was the Command Line, Harper Perennial Read More