Compare And Contrast Microsoft Dos With Unix Essays -

Compare And Contrast Microsoft Dos With Unix Compare and Contrast Microsoft DOS with UNIX Arthur Bennis Microcomputer Operating Systems CGS 1560 INTRODUCTION As is suggestive of its name, an operating system (OS) is a collection of programs that operate the personal computer (PC). Its primary purpose is to support programs that actually do the work one is interested in, and to allow competing programs to share the resources of the computer. However, the OS also controls the inner workings of the computer, acting as a traffic manager which controls the flow of data through the system and initiates the starting and stopping processes, and as a means through which software can access the hardware and system software. In addition, it provides routines for device control, provides for the management, scheduling and interaction of tasks, and maintains system integrity. It also provides a facility called the user interface which issues commands to the system software. Utilities are provided for managing files and documents created by users, development of programs and software, communicating between users with other computer systems and managing user requirements for programs, storage space and priority. There are a number of different types of operating systems with varying degrees of complexity. A system such as DOS can be relatively simple and minimalistic, while others, like UNIX, can be somewhat more complicated. Some systems run only a single process at a time (DOS), while other systems run multiple processes at once (UNIX). In reality, it is not possible for a single processor to run multiple processes simultaneously. The processor of the computer runs one process for a short period of time, then is switched to the next process and so on. As the processor executes millions of instructions per second, this gives the appearance of many processes running at once. User programs are usually stored on a hard disk and need to be loaded into memory before being executed. This presents the need for memory manageme nt, as the memory of the computer would need to be searched for a free area in which to load a users program. When the user was finished running the program, the memory consumed by it would need to be freed up and made available for another user when required (CIT). Process scheduling and management is also necessary, so that all programs can be executed and run without conflict. Some programs might need to be executed more frequently than others, for example, printing. Conversely, some programs may need to be temporarily halted, then restarted again, so this introduces the need for inter-program communication. In modern operating systems, we speak more of a process (a portion of a program in some stage of execution (CIT, 3)) than a program. This is because only a portion of the program is loaded at any one time. The rest of the program sits waiting on the disk until it is needed, thereby saving memory space. UNIX users speak of the operating system as having three main parts: the k ernel, the shell and the file system. While DOS users tend not to use the term kernel and only sometimes use the term shell, the terms remain relevant. The kernel, also known as the Real Time Executive, is the low-level core of the OS and is loaded into memory right after the loading of the BIOS whenever the system is started. The kernel handles the transfer of data among the various parts of the system, such as from hard disk to RAM to CPU. It also assigns memory to the various system-level processes that occur whenever the computer does anything. The kernel is also responsible for scheduling the CPUs operations and for letting the shell access the CPU (PC Mag, 1). The shell is the visible user interface to the OS and is a program that loads on top of the operating system and offers users commands that lets them access the OS. Strictly speaking, the shell is an input utility that offers access to the operating system. Technically speaking, the shell, being a separate program, is no t a part of the OS at all. In the UNIX world a number of shells are available, among them the Korn shell, the C-shell, the

Free Essays on Drugs In The Workplace

Random drug testing in the workplace is a good practice. Although some people believe it is a violation of privacy, companies have a business to run and don’t need the responsibility or the hassle of a drug-addicted employees and how their behavior will affect the company and its bottom-line. Employers should be allowed to test for drug use if an employee’s behavior seems appropriate, the job requires precise handling, or the driving and/or safety of others is involved. Poor judgment and impaired motor functions makes for an accident-prone employee. Operating a complex piece of machinery while impaired by drugs poses serious risks to others. Airline pilots, air traffic controllers, train operators, taxi drivers, and bus drivers are only a few examples of occupations where even the slightest bit of drug use could be life threatening for all those involved. Factory workers are not an exception. There are huge machines in a factory that when operated by an impaired employee, could cause the loss of a limb, or even the loss of a life. Drugs change behavior and limit the ability to accurately complete tasks. There is also evidence that drug dependant employees use more sick leave and medical benefits than other employees. This is a cost to the employer in many different aspects. An employee, who is addicted to drugs, may not be able to support the growing habit on their current salary. A company may find that not only are they paying for these employees’ health problems, but that they are also supporting their habit. The companies’ cash, supplies, equipment, and products may be stolen by the employee and sold to help buy drugs. In addition to the losses, the ongoing threat can mean costly security measures for many companies. Also, sick absences can mean less or inadequate production for each day a sick absence occurs. No matter what the job calls for, whether it’s flipping burgers or working on the police force, mis... Free Essays on Drugs In The Workplace Free Essays on Drugs In The Workplace Random drug testing in the workplace is a good practice. Although some people believe it is a violation of privacy, companies have a business to run and don’t need the responsibility or the hassle of a drug-addicted employees and how their behavior will affect the company and its bottom-line. Employers should be allowed to test for drug use if an employee’s behavior seems appropriate, the job requires precise handling, or the driving and/or safety of others is involved. Poor judgment and impaired motor functions makes for an accident-prone employee. Operating a complex piece of machinery while impaired by drugs poses serious risks to others. Airline pilots, air traffic controllers, train operators, taxi drivers, and bus drivers are only a few examples of occupations where even the slightest bit of drug use could be life threatening for all those involved. Factory workers are not an exception. There are huge machines in a factory that when operated by an impaired employee, could cause the loss of a limb, or even the loss of a life. Drugs change behavior and limit the ability to accurately complete tasks. There is also evidence that drug dependant employees use more sick leave and medical benefits than other employees. This is a cost to the employer in many different aspects. An employee, who is addicted to drugs, may not be able to support the growing habit on their current salary. A company may find that not only are they paying for these employees’ health problems, but that they are also supporting their habit. The companies’ cash, supplies, equipment, and products may be stolen by the employee and sold to help buy drugs. In addition to the losses, the ongoing threat can mean costly security measures for many companies. Also, sick absences can mean less or inadequate production for each day a sick absence occurs. No matter what the job calls for, whether it’s flipping burgers or working on the police force, mis...

Causes and effects of recession in uk Essay Example | Topics and Well Written Essays - 1500 words

Causes and effects of recession in uk - Essay Example The causes and effects of the recession should be examined to help scholars and the local population alike come to full understanding of the worsening situation. Historically the UK has experienced recessions five times between 1974 and 1991. In recent times the economy between July and September 2008, there were signs that the UK was entering a recession when it shrank for the first time in sixteen years. In January of 2009, confirmation that the UK was in recession came from the Office for National Statistics after showing that the gross domestic product fell 1.5pc in the first quarter of 20008. Compared to the 1990s when the economy shrank in a single quarter by 1.2pc this recession is considered to be far worse. There are several causes of the recession in the UK. While the world started to experience a recession the situation in the UK was imminent especially when the United States of America started to decline. International trade is one of the factors of the UK recession. As the economic situations in countries begin to worsen trade suffers because governments in taking several precautions do not trade with other countries as they use to thus making the global recession even worse. Consequently, if imports exceed exports this will have negative effects on the trade gap as was experienced in January 2009. The trade gap went up to  £8.3bn. The Office for National Statistics reported that this was caused by falling exports to non European countries especially the United States. Exports to countries outside of the European Union fell by sixteen percent. Economists have predicted that a weaker pound would have a more positive effect but that was not proven to be so. A signal that domestic d emands for goods were also falling was evident in the figures given for the imports of goods. These imports decreased by 1.8 percent to 28.2bn pounds. The credit crunch experienced in the United States of America was soon felt in the United