1. a) byte - Group of binary digits used to encode a single character. Most

computers use 8 –bits codes to represent one character.

bar code - A set of parallel printed lines and spaces of different thickness, normally used to store the identity of the articles on which it is printed. It is used for data capture. It can be found on stickers posted on supermarkets goods. The bars can be read by a laser scanning device or a light pen.

graphical user interface (GUI) - The use of menu, mouse and icons to select commands. It is a Human Computer Interface(HCI) provided by operating system such as Windows.

random access - The process of obtaining data from, or placing data into, a storage location in which access is independent of the order of the storage. Another name for direct access.

technical documentation - Is a documentation provided with a software/system which may give details of how to install, the minimum hardware configuration required, meaning of the error codes/messages, trouble shooting guide and a help-line telephone numbers/Email address/Internet address.

expert system - A computer program which is capable of emulating human reasoning. An expert system has access to a large database of knowledge. It can draw conclusions, make decisions and offer advice based on that knowledge.

2. a) State two reasons why automatic cash dispensing machines, sometimes

known as ATMs, are popular with bank customers.

Reason1: It can do 24-hours cash withdrawals.

Reason2: Customers can save time by avoiding standing in a queue for a

cashier in a bank and by avoiding driving through traffic during office hours.

State two bank services which are not available from the automatic cash

dispensing machines.

Answer1: Opening new account or closing an account.

Answer2: Cashing cheques.

3. Describe two differences between high-level and low-level languages.

High-level languages are problem oriented while low-level languages are

machine oriented.

High-level languages are closer to natural languages while low-level language instructions are in mnemonic form or binary forms.

4. a) What is the relationship between object code and source code?

A program code written in Assembly or High-level languages is called the

source code. When the source code is translated by an Assembler(for

Assembly language) or Compiler(for High-level language) into machine

code we call it as Object Code.

Why are programs converted to machine code before they are run?

This is because computers can only understand machine codes which are in binary forms.

5. A user switches on a microcomputer which is connected to a network. He

then word processes and prints a letter. Describe three tasks that the network

operating system might be required to do during this process.

Log-in the user by checking the password.

Loading a word processing software.

Up load the user file/work to the printer server.

6. a) Describe one application which uses batch processing.

Payroll or billing.

State two reasons why batch processing is more appropriate than real-time

processing for this application.

1. Payroll is a routine task, which held once a week or once a month.

Therefore there is no need to have an online system which is switched

on all the time.

2. A conventional configuration, which is cheaper is capable of running

batch processing.

7. a) State a household item that contains a microprocessor.

Microwave oven.

For this item describe the input to the microprocessor, the processing and

the output.

Input: Required temperature(or power), Function(Cooking, Thawing or

Baking), Type of food, Time duration and Indication to start(by pressing

the START button).

Processing: Setting the appropriate devices according to the requirements

of the user. Using feedback to regulate activity.

Output: Providing the required Function at the right Temperature for the

Time requested and stop the system at the end.

 

8. A company has decided to change from a manual accounts system to a

computerized system.

Describe two stages in this process.

1. Analysis

2. Design

Describe two effects on the employees of changing to the new system.

1. Unemployment

2. Retraining

 

9. Read this algorithm.

Counter = 0

input Character

while Character is not a full stop do

if Character = space then

Counter = Counter + 1

endif

input Character

endwhile

Number = Counter + 1

Output Number

What is the output if the following is input?

The holidays will soon be here.

Answer: 6

What is the algorithm designed to do?

Answer: To count the number of words in a sentence.

Explain why the following input would cause problems.

Holidays are over

Problem1: There are too many spaces between ‘are’ and ‘over’. As each of

these spaces are keyed in, the program will increase the number of words

by one. The count will be much more than the actual number of words.

Problem2: There is no full stop. Without a full stop the loop cannot be

ended.

Problem3: There will be no output produced.

10. Modular programming is to be used to develop a program for stock control.

State two benefits of using modular programming to develop this program.

1. All modules can be developed in less time than the whole program.

Because the problem has been simplified and more than one

programmer can work simultaneously.

2. Standard modules can be used in two or more programs. For

example, ‘DISPLAY STOCK’ can be used in a Report production

program or in a Management Information System(MIS) program.

Describe three different types of test data that should be used to test the program when it is written.

1. Normal data or standard data that are valid.

2. Abnormal data that are invalid.

3. Extreme data that are permissible– maximum and minimum.

State two items of user documentation that should be used to test the program when it is written.

1. User manual which describes the various functions of the software

performs, meaning of menu options, input format etc.

2. Technical/Operational manual, which may give details of how to install

the software, hardware requirements and trouble shooting guide and a

help-line telephone numbers/Email address/Internet address.

11. A company receives telephone orders from customers for flowers and then

sends the flowers by post. In order to this the company needs to ask for the

customer’s name, address, telephone number, credit card number and the

cost of the flowers required. In addition name and address of the person

who is to receive the flowers must be obtain.

In the box below design a suitable screen display foe entering the data.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The computer operator checks the data with the customer before entering the data into the customer database. Describe two different validation checks that could be done on this data.

1. Field length check – to fixed the number of characters for a field. Eg.

The CREDIT CARD NO. field would required 16 characters.

2. Invalid character check – to check for the validity of a field. Eg. The

NAME field will accept only alphabetical characters or spaces.

State the type of storage medium that would be used to store this database and give a reason why.

Storage medium: disk

Reason: An order would be quickly accessed and displayed on the screen if the customer phoned to query or cancel and order.

12. a) Why is a modem required when communicating with other computers on a

wide area network(WAN)?

Answer: To enable digital data to be sent down telephone lines, it must

first be converted into analog form and then converted back at the other

end. This is achieved by means of a modem.

b) State two advantages of using electronic mail (e-mail) rather than using

letter post to send a document from one side of the world to the other.

It is cheaper.

It is faster to receive and send mails.

c) Describe two ways that being able to access the WAN can change the way

that some subjects are studied.

Distance learning or video conferencing to enable students to be taught by experts.

The use of e-mail, bulletin board or chat lines for research.

 

13. A customer went to the same shop everyday for a week. The spreadsheet

shows the time in minutes which the customer spent at the checkout. Some

of the time was spent waiting and some was spent being served. The

average times spent waiting and being served are calculated in B10 and C10.

Circle and label on the diagram a cell which contains

i. numeric data

ii. a label

Write a formula in cell D2 to calculate the total time spent at the checkout on Monday.

= B2 + C2

Describe how a user can copy a formula in cell D2 into cells D3 to D8.

Highlight D2, point to the right hand bottom corner of the cell until you see the crosshair sign, then drag the cursor down from D3 until D8 to copy the formula and then release the mouse click.

A mistake was made on Friday. The serving time on Friday is corrected to 2 minutes. Which two cells would change automatically?

D6 and C10.

Describe how the spreadsheet data can be inserted into a word processed

letter to be sent to the shop’s head office.

- Opening the word processed letter.

Highlighting the appropriate data in spreadsheet.

Copying and pasting the spreadsheet into the word processed letter.

14. A car manufacturer uses a computer to design parts of cars. Describe, with

reasons, the special hardware and software that is required.

hardware: - a high resolution graphics display(monitor)

- a graphics tablet

reasons: - a high resolution monitor to get better softcopy of the design.

- a graphics tablet which contains a grid that corresponds to the

resolution of the monitor. Using a stylus or mouse, x and y co-

ordinates on the tablet can be mapped directly onto the screen.

software: - CAD software

reasons: - it can draw lines, curves, arcs, circles, 3D objects that can be

viewed at any angle and it allows scaling and drawing by the

computer.

15. A mail order company selling computers keeps details of its stock in a

database. Part of the database is shown below.

Write down an item of string data.

Which COMPUTERs will be listed if the following search condition is input:

(RAM = 32) AND (CD > 4)

CA233, CA266 and CA267.

Write down the order of the COMPUTERs after the PRICE($) field has

been sorted in ascending order.

CA166, CA201, CA200, CA233, CA266, CA 267

Explain how a macro could help if a particular search has to be done

frequently.

A macro allow you automatically to produce a sequence of keystrokes, so that, for example, you can just press one key or a combination of keys in order to open the stock file, sort the PRICE field in ascending order and print the fields of COMPUTERs and PRICE

 

16. An on-line control system is being used to maintain the correct temperature

and humidity(moisture level) in a room where lenses are being made.

i. State how the data is collected and how it is converted to enable it to be

stored.

1. Sensors would be used to detect the levels of temperature and humidity.

2. An analog to digital converter (ADC) is needed to convert the data.

ii. Describe the processing which takes place in order to maintain the

correct temperature and humidity level in the room. Refer to the use of

feedback in your answer.

Answer: Comparisons of readings will take place with the stored set of

values in order to maintain the levels of temperature and humidity in

the room. If for example the temperature is higher than required, the

sensors will be used to regulate it to the correct temperature.

Describe an additional task which the on-line control system could

undertake.

Answer: Security or manufacturing of the lenses.

 

 

 

 

17. A payroll master file contains employee records in key field order. A

transaction file contains details of new employees. Write an algorithm, using

pseudocode or otherwise, for updating the master file with these new

employee records.

Assume sorted transaction file

Read first master file record

Read first transaction file record

Compare key fields

Write record with lowest key filed to new file

Read next record from the appropriate file

Until EOF(M or T)

Write test of appropriate file to new file