• 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. Peer reviewed

    information systems assignment 2

    4 star(s)

    When the information is no longer needed the company must remove the information, this should be kept longer than necessary. It should be kept very securely and only be able to be accessed by certain people and have valid security when being moved.

  2. 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)

  1. 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

  2. Primary or Secondary Storage.

    Electrically Erasable PROM This type of memory is similar to EPROM except that is uses electrical pulses to erase and to write to the chip. It is also possible to erase the chip while it is in the computer.

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

    Conclusion In conclusion, I have discovered that the physical security of Riverside is very good. They are currently utilising 10 out of 14 of the physical security measures I suggested and the statistic of only one unauthorised entry to the complex in five years (Chelmsford Borough Council 2001)

  2. System I designed in order to produce a promotion package for her newly formed ...

    It gives their ID number, name, address, age, gender, telephone number and what way they would like to pay; either by Visa, cheque or case. Influences of Hardware and Software available The software I chose did not help as much as I expected it too much.

  1. Video Rental System

    EMP_STRT_DTE Employee Start Date Date/Time dd/mm/yyyy hr:min:sec am/pm EMP_END_DTE Employee End Date Date/Time dd/mm/yyyy hr:min:sec am/pm EMP_JOB_TITLE Employee Job title Text 255 X(255) CREATED_DATE Employee Created Date Date/Time dd/mm/yyyy hr:min:sec am/pm PURCHASE_ORDER PUR_ORDER_ID Purchase Order ID Autonumber Long Int 1-99999999 Y PK PUR_ORDER_DATE Purchase Order date Date/Time dd/mm/yyyy hr:min:sec am/pm

  2. Programming Techniques

    to be translated from one to the other, just as a letter in Chinese may need to be translated into English if an English speaker is to be able to read it. High-level Machine Language Translator code A program which is written in a high level language is called the source code.

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