CP2 Computing June 2008

[1]	State, giving a reason in each case, the most suitable secondary storage medium for each of the following situations.
(i)	Making a backup copy of a school's file server (200 Gigabytes)	[2]
	magnetic tape large storage capacity
(ii)	A school pupil submitting course work to an examination board that contains text, graphics and video (600 Megabytes).	[1]
	a CD or DVD the medium is portable.

[2](a)	Files on the hard drive of a personal computer are stored in a hierarchical directory structure. Using a diagram, show how files might be organised in a typical hierarchical directory structure used on a personal computer.	[1]

(b)	Explain why this type of structure is used.	[1]
	The structure allows files to be found much faster

[3]	A firm of solicitors using a number of stand-alone personal computers decide to update their computer system. They employ a consultant who recommends that they install a network.
(i)	Apart from sharing hardware such as a printer, give two reasons why the consultant would probably recommend installing a network.	[2]
	the computers could communicate with each other and transfer files between them. data can be shared - a central database could be used by all computers on the network.
(ii)	Give one reason why the consultant might recommend keeping some stand-alone computers.	[1]
	they would be immune from attack by viruses or hackers.
(iii)	The consultant recommends networking the computers using a star network topology. Draw a diagram that illustrates this topology.	[1]
	xxx
(iv)	Give one advantage and one disadvantage of using a star network topology rather than other topologies.	[2]
	Advantage - the breakdown of one workstation would not affect the others. Disadvantage - high cabling costs

[4]	Students enrolling on a college course are asked to provide personal details: these include their postcode and number of GCSE subjects for which they have achieved grades A*-C, which should be an integer. These details are entered into the college computer system. Describe suitable validation checks that could be carried out on this data and give an example of invalid data that would be detected by the check described. A different validation check must be used in each case.	[4]
	Postcode : Format check - first two characters must be alphabetic Invalid data - F456 7FT Number of grades : Range check between 0 and 20 Invalid data : -1

[5]	Sun All Year is a tanning studio. Client details are collected during their first visit and these details are stored on paper in files at reception. The number of clients is growing and the studio owner believes that storing the client details on a new computerised database system could improve the business. The studio has found that contacting clients using the paper-based system is extremely time consuming.
(i)	Describe one other possible problem with the current paper-based system that may lead to the studio losing business. Describe how a computerised database system could solve this problem.	[2]
	Problem : Changing data is difficult on paper. Incorrect data may lead to customer problems. Solution : Database records are easier to alter and save.
(ii)	Describe two ways in which the studio could use a computerised database system containing the client details to attempt to increase the number of visits from clients.	[2]
	A mail-merge could be used to send all the clients information about special offers. The database could be used to search for all clients who have only visited once, and send them reminders about the studio's facilities.

[6](a)	The operating system of a computer provides an interface between the hardware and the user. Describe three typical functions of the operating system from the user's point of view.	[3]
	loads and runs application programs maintains security by asking for usernames and passwords to authenticate users outputs error messages (Eg printer out of paper)
(b)(i)	A gas company uses batch processing to produce quarterly bills. Describe how batch processing works in this case and explain why it is the most suitable mode of operation.	[2]
	all the jobs are collected and run together at the same time there is no need for human intervention / can be run at off-peak usage times such as night or weekends.
(ii)	A nuclear power station uses real-time processing to control reactor temperature. Describe in detail how real-time processing works in this case and explain why it is the most suitable mode of operation.	[3]
	readings from sensors are input to the controlling computer... ...that outputs control signals to activate devices if necessary Inputs are immediately processed and any required actions are done straight away.

[7]	A holiday company specialises in adventure ski holidays. The company has thousands of customer records which are stored on a computer. These records include information about customer financial status. The manager of the company is concerned about computer crime and believes that some computing staff may be benefiting illegally from their position.
(i)	Describe one way in which a dishonest employee with access to customer records could illegally benefit from their position in the company.	[1]
	employee may accept payment to change customer record to show incorrect credit status
(ii)	All company employees are asked to comply with the company code of conduct. Describe one effect a code of conduct may have on the behaviour of employees.	[1]
	all employees would act in a consistent manner
(iii)	Security systems introduced by the company include the use of usernames and passwords. Describe two other measures that could be adopted to prevent its computer staff illegally benefiting from their position in the company.	[2]
	checks of accuracy by senior staff restricting database access to trusted members of staff
(iv)	The company has registered with the Data Protection Commissioner. The company complies with two principles of the Data Protection Act by processing the data lawfully and storing the data securely. State three other principles of the Data Protection Act with which the company will need to comply.	[3]
	data must be kept up-to-date data must be relevant and not excessive for the purpose data must not be stored for longer than necessary

[8](a)	Explain the difference between serial file organisation and sequential file organisation.	[2]
	serial file - records are added to the end of the file as they arise. sequential file - data is sorted in order of a key field.
(b)	Records can be fixed length or variable length. Give one advantage of a fixed length record and one advantage of a variable length record.	[2]
	Advantage of fixed length - processing/searching of data is faster Advantage of variable length - file sizes are smaller so they are faster to load, save and transmit down networks.
(c)(i)	A water company sends bills out to every customer. Draw a detailed diagram that clearly shows how the master file and the transaction file are used to produce the bills.	[4]

(ii)	When bills are produced, several items of data are updated in the master file. State one data item that is updated.	[1]
	Total amount of water used by the customer

[9](a)	What is the computer term for the number of bits that can be processed as a single unit by the CPU?	[1]
	a word
(b)	A computer often has to exchange signals with a peripheral device to establish their readiness to send or receive data. What is this communication called?	[1]
	handshaking
(c)	Hardware and associated software is required for communication to take place between the processor and a peripheral. What is the name given to the hardware?	[1]
	interface

[10](a)	Explain, using a diagram, how four parallel processors P1, P2, P3 and P4 could be used to find the total of eight numbers 3, 7, 5, 8, 2, 9, 1 and 6.	[2]
	P1 : 3 + 7 = 10 P2 : 5 + 8 = 13 P3 : 2 + 0 = 11 P4 : 1 + 6 = 7 P1 : 10 + 13 = 23 P2 : 11 + 7 = 18 P1 : 23 + 18 = 41
(b)	Give one advantage of using parallel processing rather than a single processor.	[1]
	processing is much faster

[11].	In the following question, additional credit (up to 3 marks) will be gained if your answer demonstrates skill in written communication. A parcel delivery company has many drivers delivering parcels. The parcels are loaded on a van in the morning in the order required for the delivery route. Every parcel has a delivery note that contains all the delivery details and has space for the customer's signature. The company office frequently needs to contact the drivers to give new delivery instructions. The driver often has to contact the office for alternative routes to avoid congestion and to give reasons for failed deliveries. This communication is currently made using mobile telephones. The company decides to replace the driver's mobile telephone and paper delivery notes with a new hand held computing/communication device. Describe what functions this hand held device could carry out. Describe what methods of input would be most suitable to perform the functions described.	[7+3]
	The device can store a database of the details of the deliveries for that day. These could be sorted into delivery order. The device could act as a GPS satellite navigation system to help the driver plan the route to the delivery address. GPS also can be used for the office to know where the delivery van currently is. When each delivery is made, the customer can sign on a touch-screen on the device to confirm the delivery and the signature is saved. The device could be used to contact the office by email or messaging service over the Internet using wireless technology. Each package for delivery would have a barcode on it, and a barcode reader on the hand-held device could read the barcode to identify the package. The device would also have a touch-screen device for input using a stylus.