• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Identify and fully describe the main developments of Operating Systems, giving examples of their origins and use.

Extracts from this document...


Chris Oliver Unit 27 - Operating Systems OLI02032345 1. Identify and fully describe the main developments of Operating Systems, giving examples of their origins and use. Batch Operating Systems were an early operating system available, and were first introduced in the mid 50's. They were designed to make human manual work easier; humans were replicating identical jobs over and over again, hence in batch. A batch operating system keeps itself eventful; it does this by taking jobs from a batch queue, instead of waiting for people to submit jobs. The jobs are then processed one or more at a time under control of the operating system, however most jobs undertaken in this operating system would be single-task. These type of operating system were often left to work overnight, mainly because the jobs were 'batched' the next job in the queue would be commenced as soon as the previous job had been completed, this way of processing would allow for a large work load to be automatically completed without the requirement to wait and tell the computer to do the next job. Real Time Operating Systems (RTOS) are often embedded, meaning a integral part of a system inside another device. They have very little user interface capability. Real time operating systems like their name implies, respond to an input immediately. "Real time operating systems are capable of processing data so quickly that the results are available to influence the activity currently taking place." [Computer Science 5th Edition, CS French, Ashford Press Gosport, 1996] Real time operating systems guarantee a certain capability within a specified time constraint; these time constraints are usually very rigid. If the system does not conform to this time limit, the system ultimately fails. They are used for various purposes; a few of these are medical equipment, industrial control systems and car computers. Parallel Systems have more than one processor to carry out a single job. ...read more.


This is handled by using virtual memory; using the hard disc drive as a temporary memory source for processes and data. This can benefit the user in various ways: - The user is not rigidly restricted to space available. Using a large virtual memory space provides convenience for instances where large programs etc. are required to be stored in memory. - Users are using less physical memory; therefore the system can handle more users on the system. High Speed Cache is a fast memory storage; cache predicts the data that the CPU may need next, it then retrieves it from RAM and places it in to the high speed cache, this speeds up system performance, as cache is a lot faster than RAM is in providing for the processor. The operating systems task is to control an even flow of the processes and decide where they should go practically, moving processes to the best location as the scheduler asks it to do so. This scheduler knows what process is next in line therefore can tell memory it is next and to move it to a suitable location for it to be quickly accessed. Paging Paging is a method used in operating systems to make a program's memory non-contiguous, in simple terms; allowing a program to be allocated to any memory location available. This is used when a bulk of data is bigger than the memory allocation it has been given; it firstly fills the memory allocation provided, and then stores the rest of the data in any space available in memory. This method of splitting the data is known as 'Fragmentation'. This decreases system performance. Defragmentation To enhance the performance of the memory of a secondary storage medium, the operating system runs an operation called 'Defragmentation'. Defragmentation is a process that sorts data in to a contiguous sequence. If a non-contiguous set of data is found, it will be relocated and stored as a whole. ...read more.


Size constraints are a major problem with RAM disks, as they are limited to that only of the RAM contained in the machine. For example in modern home computer systems 256mb of RAM is contained, therefore only 256megabyte of RAM disc can be used. 256mb in today's computing is very little in comparison to what users require. OS Services - files, copy, delete, rename, view, find, backup Directories - create, rename, list, delete Programming, Open, close, read, write, seek File allocation methods, FAT 32, NTFS, UNIX, Disk caching RAM disk Defragmentation I/O System Management DMA DMA takes control of the system by imitating the processor; it does this to enable itself to transfer data to and from the memory using the system bus. Buffering is required primarily because of the slow nature of I/O Device function. It is a way of smoothing out an I/O operation, Virtual Segmentation - each process is divided in to slices (segments) non-resident Caching and Spooling of Input and output devices Drivers System Components ( CPU, RAM, System Bus, Local Buses, Device Controllers, Control Registers, Devices). IO response System (polling, interrupts, I/O, DMA Kernal Layers, Purpose, Device, Drivers, System calls Device Management Device management controls hardware resources; this includes the control over selection and operation of the devices used for input, output or storage. 2. Select an appropriate type of operating system for the following ICT needs, giving the choice of current operating systems [trade names]: a) Local council office department in charge of the collection, and distribution of council tax. b) A national car-rental agency, whose main computing centre is located in Sheffield, through which all of the daily transactions for the business are conducted. c) An electro-plating circuit board manufactures. d) A travelling company representative, who uses technology to keep in touch with his office. 3. Research and identify the different operating systems currently available for desktop computers. From your research and investigations of these operating systems you must critically evaluate them. This evaluation should clearly demonstrate your understanding of the differences found including and potential disadvantages. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Computer Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Computer Science essays

  1. Marked by a teacher

    Memory Managment Operating Systems

    3 star(s)

    This process is controlled by the memory management unit, also know as the MMU. Dynamic Loading and Linking The operating system memory management is also capable of dynamic loading and linking, this is a process required by the state of address binding.

  2. Marked by a teacher

    The systems development life cycle (SDLC) is a conceptual model used in project management ...

    3 star(s)

    Link: http://www.oddtodd.com/mw/clip_image003.gif One such approach/process used in Software Development is "The Waterfall Model". Waterfall approach was first Process Model to be introduced and followed widely in Software Engineering to ensure success of the project. In "The Waterfall" approach, the whole process of software development is divided into separate process phases.

  1. Peer reviewed

    information systems assignment 2

    4 star(s)

    However should somebody request information which is covered by the FoIA law, public authorities legally have to answer any requests within 20 days. Below, is an example of the constraints within the FoIA. It also shows below, that decisions are made based on these information requests and bad decisions can then be made.

  2. Computer systems assignment 1

    First I take a look at the motherboard and ribbon cables. I take a mini vacuum cleaner with brush designed for computers and carefully hoover the dusty motherboard and cables. When done I do the same with the components and I make sure that there are no liquids inside the

  1. Control Unit, Memory Unit, and Arithmetic Logic Unit. The CPU or Central Processing ...

    The characters are printed using magnetic ink. The value is that the characters are readable by humans and by machines. The only common use for such characters is the data printed on the bottom of cheques containing account identification. e)

  2. Stace & Dunphy (2001) identify five dilemmas of change

    The networks of an organization function as culture maintainers - organization members who communicate in predictable ways about predictable things based on history. Fundamental and lasting change requires the transformation of the networks that are the foundation for communication and relationships within the organization.

  1. GCSE I.T Security Case Study - Riverside Leisure Centre

    * Mostly manually operated or force operated. This is better than if it was automated because mistakes are rare and shifts are operated so workers are constantly awake and 'on the ball'. To every good system there is a downside.

  2. I have been given the task to design a database for a company called ...

    up certain fields in a certain table and searching for something within that field. Parameter Queries A parameter query is more complicated than a simple query. It is a query which when runs, displays a dialog box, which asks you for information e.g.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work