Wednesday, February 9, 2011

Answers 1.2



1.      Define what is meant by the term operating system.                             (2)

   A.  -A (suite of) programs…
         -which run the basic functions of the computer/controls the hardware…
         -giving an environment in which to run application software.
         A question which begins with the word define, leaves very little room for manoeuvre because it is asking for a standard answer. This is not an opportunity to show your prowess by making up an answer that is original - there aren’t any. Note, also, the fact that three answers have been given. Always try to give one more answer than seems to be required by the question.
       
  If you look at a mark scheme for an examination paper, the mark points are listed as a set of bullet points so there is no reason why you should not do the same. This style of answer helps you to write down your thoughts easily without getting confused by the language. The purpose of this examination is not to test your ability with English, rather to test your knowledge of computing.

2.      Give two reasons why an operating system is likely to be stored on backing storage rather than in the memory of the computer.                                     (2)

   A.  - A full operating system requires a large amount of storage space that is better utilised in the computer memory for applications
         - Storage of the operating system on backing storage allows for easy upgrading or changing from one system to a different one.
        
Note that the temptation to call the operating system the O.S. has been resisted in the answer. In general, do not use abbreviations in your answers. There are exceptions, where the abbreviation is the accepted form, but your own versions may be ambiguous or, even, not understood by the examiner. If you do need to use an abbreviation, because the term is to be used a number of times, give the term in full with the abbreviation that you want to use in brackets after it. For example, the first time that you use the term operating system write   “…operating system (OS)…” you can then use OS as often as you like in the rest of your answer.

3.      Distinguish between a multi-tasking and a multi-access operating system.       (2)

   A.  - A multi-tasking operating system is one where the user of the machine is given the impression that they can carry out more than one task at a time.
         - A multi-access operating system is one where it is possible for more than one user to access the system apparently at the same time.
         
 Note that there are a large number of points that could have been made about both of these operating systems, but most of them would not answer the question. It is important when answering a question starting with ‘distinguish’ to choose facts that show a comparison.


4.      State what is meant by a distributed system, and give an advantage of this type of multi-access system over a simple network of machines.(2)

   A.  - A distributed system is one which uses many storage locations on different machines to store software and files.
         - Access to files can be speeded up because more than one file command can be carried out at a time.
         When an advantage is asked for it is normal to state in the question, either explicitly or implicitly, with what the comparison should be made. Be careful to give an advantage using this comparison and not a more generalised one.

5.      A computer operator takes phone calls from the public who ring up asking whether a particular item in a catalogue is available. The operator needs to type in a series of responses to questions put to the caller, so that the computer can check the file and determine whether there are any of that item available. Design a screen interface that would be suitable for the operator to use.                                               (4)

   A.  - Form type interface
         -  Catalogue number
         - Space for the description of goods which will be filled in by the computer itself
         - Spaces for computer to produce availability and price
         - Laid out with spaces for input.
        
What is just as important here are the things that would not be on the screen. The question makes it quite clear that there is no ordering going on, so spaces for name and address, or method of payment, are not only going to score no marks, but will probably be penalised because they demonstrate that the candidate has not understood the question. In this type of question it is important to demonstrate that you have taken the situation into account.

6.      The technician responsible for maintaining the system in question 5, uses a command line interface.
         a) Explain what is meant by a command line interface.             (2)
         b) Give two advantages and one disadvantage to the technician of using a command line interface rather than a menu based interface.                         (3)

   A.  a)-Series of commands typed at a screen prompt…
         -which give specific instructions to the computer.
         b)Advantages:
         -Entire system is available to the technician
         -Access to the particular part of the system required is gained more quickly than using other types of interface.
         Disadvantage:
         -The technician needs to know the commands that are available
         -The technician needs to understand the way the system is designed so that it can be navigated efficiently.
        
Note. The language used in this answer is not the sort of language that a candidate will use in an examination. Don’t worry about this. Answers like “so that you can get around the system” are perfectly acceptable.

7.      State three different types of utility software and explain why they are necessary in a computer system.   (6)

    A. - Disk Formatter
         - to divide up the surface of a disk so that the computer can use it.
         - File handling
         - to allow the computer to manage files e.g. storing, and finding them.
         - Hardware driver
         - to give the instructions necessary for using a piece of hardware.
         - File compressor
         - to reduce the size of files so that transmission can be done faster.
         - Virus checker
         - to find and delete viruses on a system before they can damage files.
          
Note. Lots of answers here, but they are all from the syllabus, none are made up because there is no doubt about these whereas there may be doubts if you do not stick to the accepted ones.
         No proprietary brand names are used. Scandisk and Winzip are brand names and will not get the marks.
         Be careful about giving different types – file storage, file sorting and file deletion are all utility programs but they are all file handlers, so would only get one pair of marks.


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