CP2 Computing June 2002

Describe the difference between a local area network and a wide area network, giving an example of a use for each type of network.

[3]

LAN is a network of computers linked together using cables - usually on the same site.
Eg a school network
WAN is a network of computers linked by telephone or satellite.
Eg Branches of a bank in different countries may be networked using a WAN

2(a)

Sian works from home and has a number of directories on her computer. Part of the file structure she uses is shown below.

(i) What name is given to this type of "tree" file structure?

[1]

a hierarchical structure

(ii) What is its advantage over using a single directory?

[1]

It is easier and therefore faster to find a file.

(b)

(i) Give one advantage of storing data on an optical disc compared with storing data on a floppy disc.

[1]

Much more data can be stored

(ii) Give one advantage of storing data on a floppy disc compared with storing data on an optical disc.

[1]

Smaller size and more robust so it is easier to carry around./ Easier to delete and re-save

(c)

What is meant by the term cache? Why might cache be used?

[2]

Cache is an area of hard disc which is used as memory. This may be needed when software requires more memory (RAM) than is available.

A video rental store uses both a bar-code reader and a keyboard to input data to its computer system. Data validation methods are used with some of the data input.

(i)

Describe one application in the video rental store where the bar-code reader is preferable to the keyboard, describing why it is more suitable.

[2]

Inputting details of videos and members when a video is hired out. Data can be automatically read from barcodes on the video and membership card, making input faster and more accurate than keying.

(ii)

Describe one application in the video rental store where the keyboard is preferable to the bar-code reader, describing why it is more suitable.

[2]

Entering details of new members or videos. The data is not available on a barcode.

(iii)

I. What is the purpose of data validation?

[1]

To make sure that data is 'sensible' before processing it.

II. State two types of data validation which might be used by the video rental store, giving a clear example of how this would operate in each case.

[4]

Length check - video code numbers may all be the same number of digits and the validation check will see if this is correct.
Range check - the date of rental is checked to make sure it lies within a certain range of dates.

Explain what is meant by each of the following terms:

(i)

address bus;

[1]

a path between the CPU and memory along which the address of data being accessed passes.

(ii)

control bus.

[1]

a path between all parts of the computer along which control signals pass to make sure operations within the computer happen at the right time and in the correct sequence..

5(a)

Using a diagram, and giving an appropriate example, describe in detail each of the following file structures:

(i)

serial access file;

[3]

data is placed into a serial access file at the end.
when data is to be accessed, each record is searched from the start of the file until the requested record is found.
Example : a daily transaction file for mail order catalogue sales.

(ii)

sequential access file.

[4]

each record has a unique key field
the records in a sequential file are sorted in order of a key field.
when a new record is added, it is 'inserted' into the correct position in the file.
access to a record may be by using a binary search method.
Example : a master file of items for sale in a mail order catalogue, sorted by item code number.

(b)

Files often have variable length records.

(i)

State an advantage of variable length records.

[1]

storage sizes are smaller

(ii)

Give an example of the use of variable length records.

[1]

A file where each record may have a different number of fields. Eg a file of pupils names and the subjects they take for A Levels. Each field is separated by an end-of-field marker ('#')and reach record is separated by an end-of-record marker ('@')

etc

Coolcoaches is a small company which organises coach trips to local attractions such as stately homes, theatres, theme parks and nature reserves. Some trips are in the evenings or at weekends, while others are during the day, to appeal to as wide a range of possible customers. Coolcoaches uses various methods to try to increase business, such as advertising on posters and in the local press. It also sends information to customers who may be interested in planned trips.

Coolcoaches uses a paper-based system to store information about previous customers. However, the business is expanding, and it is increasingly clear to the owner of Coolcoaches that a paper-based system is no longer adequate.

(i)

Describe two possible problems with the current paper-based system.

[2]

too much storage space might be needed. Paper is bulky.
it might be too slow to find details about a particular customer.

(ii)

Data stored in the system include basic customer data such as name and address. Describe two other items of data which should be stored in the system.

[2]

a customer identification number (key field)
a coach trip ID number which that customer has booked.

(iii)

Describe, with reasons, the most suitable type of software for this application.

[3]

a database would be needed for this application.
It would allow data to be stored systematically, sorted and searched to find information.

(iv)

The owner of Coolcoaches has recently decided to use the internet to advertise and sell planned trips. Describe two ways in which this might improve business.

[2]

a wider audience could be reached with advertising.
financial transactions may be done over the internet using credit card facilities.

(v)

Describe three ways in which the Data Protection Act will affect Coolcoaches.

[3]

they will need to register their data with the DPA as it is personal data about their customers.
they will need to make sure the data is kept secure
they will need to make sure the data is kept up-to-date and only used for the purpose for which it was registered.

A large firm of architects which has offices in a number of cities uses email extensively.

(i)

Describe three ways in which email might be particularly useful to this firm.

[3]

clients may be contacted quickly to discuss contracts
management may contact all the employees at the same time with news or instructions etc..
plans may be attached as files to emails and sent to clients.

(ii)

The managing director is very worried about the increasing use of email in the firm. Describe three concerns which the managing director might have.

[3]

employees may be wasting company time by sending personal emails.
viruses may be received with incoming emails.
there may be breaches of security - employees may be disclosing sensitive information to the wrong people.

(iii)

There are also health concerns over the widespread use of computing equipment. Some workers are concerned about possible damaging effects on their fingers and wrists. Describe two other health concerns associated with the use of computing equipment.

[2]

eyesight may be affected by poor monitors and incorrect lighting.
back and neck strain may be caused by incorrecr posture.

A computer uses a handshaking procedure when it communicates with a printer. The computer sends a message to the printer, to find out if it is ready to receive data.

Describe the communication that is likely to take place after this message.

[2]

the printer will respond with a signal to indicate it is ready to receive data.
the data is then sent to the printer for printing.

In the following question, additional credit (up to 3 marks) will be gained if your answer demonstrates skill in written communication.

The operating system of a microcomputer provides utilities for the user and manages the computer's resources. The features of the operating system include multi-tasking and spooling, and it provides security.

Describe in detail the function of the operating system of a microcomputer, paying particular attention to the points in italics in the above paragraph.

[6+3]

The operating system is a set of programs which manage the operation of a computer. These will include utilities which perform such tasks as file management (deleting, copying, editing) and day-to-day tasks such as organising disc space, formatting, making backups..etc

One of the tasks of the operating system is to manage the computer's resources. When data is loaded into memory (RAM) the OS will decide where to store it, and will allocate memory needed for any running processes.

In a multi-tasking system, a number of programs are loaded into memory and ready to run. The OS will decide the order in which these will be run and allocate CPU processing time to each.

When output (eg to a printer) is requested by a program, the OS will send the output to hard disc before it is output to the printer. This is spooling and means the processor does not have to wait for slow peripherals.

The OS will also manage the security of the system, checking passwords, and only allowing access to authorised users.