Marking Scheme for the Sample Exam Paper

Transcription

1 INFORMATION SYSTEMS EXAMINATION BOARD BUSINESS SYSTEMS DEVELOPMENT CERTIFICATE IN INFORMATION AND COMMUNICATION TECHNOLOGY for the Sample Exam Paper As this is a sample paper, both the paper and the marking scheme may be freely copied for your private use.

2 Hardware, Software & User Interfaces QUESTION 1 What is RAM? Briefly explain why it is necessary in a computer. Marking scheme Main memory 1 mark Temporary storage (volatile memory) 1 mark Used for running programs and storing data which is about to be processed 2 marks (maximum is 3 marks) QUESTION 2 What are the main differences between a hard disk and a floppy disk? Hard disk fast access to data, expensive, not removable, stores vast volumes of data. Floppy disk slow access to data, cheap, removable, stores small volumes of data. QUESTION 3 A byte is made up of 8 bits (i.e. a combination of eight 0 s or 1 s). What are bytes a measure of? (1 mark) : Size of memory QUESTION 4 What is a Megabyte? : 1,000 kilobytes (1,000,000 bytes approximately) (1 mark) QUESTION 5 How much memory is necessary to store 10 characters? : 10 bytes (1 mark) QUESTION 6

3 What is software? (2 marks) Set of instructions (along with data) to the computer which tells the computer to do things 2 marks It is the intangible part of the computer systems (as opposed to the hardware) 1 mark (Total marks - 2 marks maximum) QUESTION 7 What is an Operating system? Piece of software which allows users to interact with machine 1 mark Shares resources among many users. 1 mark Allows users to: use/control peripheral devices 1 mark Run programs/applications 1 mark (3 marks maximum) PC Operating Systems and Application Packages QUESTION 8 What is meant by file and file name (in the context of a computer system)? (2 marks) File collection of instructions (program) or data 1 mark File name name given to a file allowing both user and op system to identify it. 1 mark QUESTION 9 What is a computer package? Give some examples. off the shelf (i.e. 3 rd party vendor) software 1 mark examples: word processor spreadsheet database accounts package drawing package project management tool etc (1 mark each maximum of 4 marks)

4 QUESTION 10 What is a High Level Language? Give some examples. An English-like language for writing computer programs. Needs to be translated into machine code 1 mark Examples: Cobol Basic Pascal PL1 RPG etc 1 mark each maximum of 3 marks Total = maximum 4 marks QUESTION 11 Why is software divided into modules or components? To facilitate: structured design Re-use of code Ease of maintenance programming in teams ease of extension/modification reduced error propagation 1 mark each maximum of 4 marks Data and Information QUESTION 12 What is the difference between data and information? Information is structured data 1 mark Data are raw facts, information is something that is useful at some point in a business process 2 marks Data to one person is information to another and vice versa 1 mark QUESTION 13

5 What do we mean by the flow of data in an organisation? (5 marks) Horizontal flow: Data is passed from one stage to another in a business process, as businesses are organised around processes rather than function, data has to flow from one dept. to another - 3 marks Vertical flow: data used to control and monitor a business 2 marks QUESTION 14 Why is it important to have accurate data in a computer system and how can this be achieved? (5 marks) Garbage in, garbage out a business cannot operate properly/efficiently/legally if it holds inaccurate data 2 marks Achieved by: Validation and verification on input Designing internal data integrity processes Restricting access to authorised people Accurate specification of calculating and reporting parameters - 1 mark each maximum of 3 marks Basic Computer Functions QUESTION 15 What is JCL and how is it used? Job Control Language is a set of instructions given to a computer which defines, to the operating system, how a batch job will be processed. Including: schedule, resources, devices used, data storage and what to do if an error occurs 4 marks QUESTION 16 Briefly explain four ways of maintaining data security in a computer system? (8 marks) Restrict access to system to appropriate people Restrict access to data to appropriate people Audit/monitor system usage.

6 Physical security 2 marks for each total of 8 marks QUESTION 17 What does a TP Monitor do? Manages transactions i.e. packets of data to/from screen conversations Facilitates systems scalability Optimises calls on databases Balances workload between available resources - 1 mark each 4 marks maximum PCs, Mainframes & Networks QUESTION 18 What is a Local Area Network? Local Area Network: Computers (clients and servers) along with peripheral devices connected together using cables over a small geographical area e.g. an office. The nodes on the network are able to communicate with each other at high transmission speeds and share data. 3 marks QUESTION 19 What is the advantage of a LAN over stand-alone computers? Software and data can be easily shared Peripheral devices can be shared Easier to manage user requirements 3 marks QUESTION 20 How does a Token ring LAN work? Illustrate your answer with a diagram if necessary. (8 marks)

7 2 marks Token-ring networks make use of a token to determine which node has the right to use the cables to transmit data (token passing). The free token circulates around the ring until a node has data to transmit. This node collects the token, adds its data and transmits it to the ring. When the packet returns, it removes the data and releases the token, allowing other nodes to transmit. As a result, the usable bandwidth is around 95% of the maximum bandwidth. 6 marks