• Distributed data processing is where computers located in physically separate location transmit data after processing to a server computer that updates the master file. Time-sharing on the other hand is where various terminals transmit data to be processed by a central computer's CPU. Each terminal's tasks are allocated a time slice of the CPU

Both translate source code written in high level programming languages into machine code.
Compiler: Produces a single executable file that is portable between machines
Interpreter: Source code needs a special environment to run
Compiler: Needs to be compiled for a particular architecture
Interpreter: Can run on any architecture that has the translator/interpreter
Complier: Entire source code file is translated at once
Interpreter: Code is translated line by line
Compiler: Provides error report at the end of the compilation
Interpreter: Errors more obvious in the sequence
Compiler: The program source code is not available (so helps protect IP)
Interpreter: Source code is available
Compiler: Only has to be translated once (affecting the speed of execution)
Interpreter: Has to be translated each time, therefore (affecting the speed of execution)
Compiler: Requires two files to be maintained (one for execution and for editing purposes)
Interpreter: Requires only one file to be maintained
 

The organisation of files is in a hierarchy/tree structure
A node is either a folder/directory/sub-folder/sub-directory or the file itself
The top node/folder/directory/drive is the root

(a) Identifying technologies that may be used in a proposed system

• System Analysis/Information gathering/Problem recognition

(b) Identifying the shortcomings of the old system

• Problem definition

(c) Prepares the software migration plan

• Implementation stage

• Implementation

17. a) i) Explain the term search as used in the Internet.                                            [2]

A web based application that locates items or information from the World Wide Web

ii) Peter intends to download a movie from the Internet. State the three factors that may determine the total time taken to complete the download.                                           [3]

• Size of the video/format
• The bandwidth of the media/speed of network/network traffic
• Type of browser software
• Background activities running in the computer
• Restrictions enforced in the computer/firewall/antivirus
• Speed of the computer/CPU speed
• Size of RAM

b) Wakulima online is an organization that runs a web based system for assisting farmers to obtain market for their produce. State four technological reasons that may cause a farmer not to access the organization’s system.                                                                                  [4]

• Poor network/lack of connection
• Software failure in the system

• Hardware failure
• Lack of access rights
• System overload/hanging
• Lack of skills/disability/illiteracy
• Lack of power supply

c) Explain a situation when each of the following Desktop Publishing program features may be used when creating a publication:

i. Cropping                                                                                                               [2]

Applies to graphics – used to trim/remove/hide some portions in the graphics

ii. Transparency                                                                                                         [2]

Used to make background of a graphic to be clear/visible

d. List two areas where infrared waves are used in data communication.                             [2]

18. a) List four activities of the planning stage of systems development.                             Ignore this question, marks redistributed elsewhere

b) Explain a circumstance when each of the following feasibility studies are carried out during systems development.

i. Technical                                                                                                               [3]

Done to determine whether technology exists to support the proposed solution

ii. Economic                                                                                                              [3]

Done to determine whether the proposed solution is economically viable

iii. Schedule                                                                                                               [3]

Done to determine whether the proposed system can be done within an acceptable time.

c) Table 1 and Table 2 are related tables in a database. Use them to answer the questions that follow.

Table 1

Table 2

i. Identify the appropriate primary key for each table.                    [2]

Table 1 – Dept code, Student Registration No

ii. Explain two benefits of enforcing referential integrity in the database. [4]

• No record can be added in Table 2 if its corresponding record in Table 1 does not exist
• No record in Table 1 can be deleted without first deleting the corresponding record in Table 2
• Reduces data redundancies/ensures integrity
• Prevents deletion of related table

19. a) Describe each of the following validation checks as used in data processing.

i. Preserve check                                                                                                      [2]

Ignore this question, marks redistributed elsewhere

ii. Data type check                                                                                                    [2]

Ensure correct type of data is entered for the field

iii. Check digit                                                                                                           [2]

This is a number added/calculated by the computer to a binary number. The check digit ensures correct transmission of the binary number.

b. Write each of the following abbreviations in full:

i) BCD                                                                                                                                    [1½]

Binary Coded Decimal

ii) EBCD                                                                                                                                 [

This question was thrown out and marks redistributed elsewhere

iii) ASCII                                                                                                                    [1½]

American Standard Code for Information Interchange

c) Using 10-bits binary number system, perform the following decimal operation using two’s complement.                                                                                                                                   [6]

12910 - 12810

+129 = 00 1000 0001

128 = 00 1000 0000

-128 = 11 0111 1111 (ones complement)

                            +1

          11 1000 0000 (Twos complement)

129- 128

     00 1000 0001

+ 11 1000 0000

 100 0000 0001

Hence = 00 0000 00012 or 12 (the overflow bit is ignored)

A backup is a copy of data that can be used if the original data is lost.

(i) the potential health hazards of this type of work,

• backstrain due to long periods of immobility
• eye strain due to long periods of staring  at the screen
• RSI- continual use of the same muscle group

(ii) the ways that management can help to overcome the effects of the health hazards.

• Move around regularly
• use ergonomic chair
• use anti-glare screen
• use of wrist pads

1.State two reasons for the increased use of laptop computers in government offices. [2]

They are small and fit in a small storage space

They are light weight hence can be carried to areas where their services are required

The monitor, system unit, keyboard units are integrated together

Easy to share

Have rechargeable battery

Have low power consumption

2.Computer network technicians prefer to use command-line based operating systems when configuring networks. State three reasons for the preference. [3]

Do not take up a lot of memory

Have direct access to most hardware devices/provide complete control during configuration

Cheaper to acquire as some are freeware/shareware

Faster to execute commands

Difficult to hack/more secure

More stable

3.State three measures that should be put in place in a computer laboratory to safeguard users’ health. [3]

• All power cables must be insulated and hidden from users
• Furniture used must be of standard
• Room should have adequate lighting
• No overcrowding
• Monitor should be fitted with anti glare
• Avoid dust
• Avoid slippery floor
• Avoid bright coloured walls
• Promote use of ergonomic devices

4.State three ways in which barcode readers may be used in schools. [3]

Take inventory of items

Transactions in the school library

Keep track of movement of goods

Track students in and out of school

Used to register roll call

5.State three advantages of flat panel monitors over cathode ray tube monitors as used in computers.                                                                                                                     [3]

• Compact and light/portable/less bulky/occupy less space
• Consume less power
• Low angle distortion
• Improved color depth
• Higher resolution
• Have less radiation
• Produce less heat

6.State three possible reasons for the extinction of daisy wheel printers in the market. [3]

• Slow
• Noisy
• Lack of graphic support
• Monochrome printer
• Supported on font type and size

7.State three ways in which an operating system secures a computer system.             [3]

• User authentication
• Secure user accounts with privileges
• Encryption of data
• Keeping log files
• Auto backup and auto recovery features
• Inbuilt antivirus

8.A law firm prefers to use hard copy output when handling documents for legal matters. State two reasons for this preference.                                                            [2]

• Can be used without electricity
• Can serve as physical evidence/exhibit
• Not easy to change content without leaving evidence
• No need of computer knowledge

9.State the function of each of the following feature in a word processor

a. Thesaurus                                                                                                                    [1]

Feature that suggests words with similar or opposite meanings to the selected word

b. Comments                                                                                                                   [1]

Feature that allows a user to attach remarks

10. With the aid of an example, explain the term multi-level list as used in word processing.                                                                                                                [3]

1. Chapter 10
   1. Summary
      1. xxxxxxxx

Formatting style that shows listed items at different level instead of using one line

11. Distinguish between real-time operating system and distributed operating system. [3]

Accept answers based on data processing concept

12. Explain the function of protect sheet feature in a spreadsheet program.                   [2]

A tool/feature that prevents unwanted changes to the spreadsheet. Requires a user to key in a password inorder to make changes

13. State four computer based careers introduced as a result of computerized data processing method at the airport.                                                                                     [2]

• System analysts
• Web designers
• Network administrators
• Network technicians
• Programmers
• Database Administrators

NB/ Accept any computer based career

14. In a spreadsheet, the formula = If(A1>10,A1*77,A1*50) is entered in a cell. Interpret the results.                                                                                                                        [3]

Checks the value in cell A1if it is more than 10, if the comparison is true then the outcome of the value in cell multiplied by 77 is displayed, else if it is false the results of the value in cell A1 multiplied by 50 are displayed.

15. State a stage in systems development cycle where each of the following activities are carried out:

a. Identifying the technologies that may be used in a proposed system.                       [1]

Accept any sub stage within system analysis e.g. requirement specification, problem definition, information gathering, etc

b. Identifying shortcomings of a system.                                                                       [1]

All stages of system development

c. Preparing the system migration plan.                                                                          [1]

Implementation stage

The following are some of the possible definitions:

It is system software designed to help the users to analyse, configure, optimize, or maintain a computer

System software that helps maintain the proper and smooth functioning of a computer system

Examples include antivirus software, Disk clean-up tools, disk defragmenters, backup software, etc

SECTION A (40 MKS)

Answer all the questions in this section in the spaces provided.

1.Describe the computer booting process.    (2 mks)

2. State the functions of the following keys on the computer keyboard   (2 mks)

  a) Backspace

  b)Insert (ins)

3. Jane has noticed the following problems with her computer keyboard    (2mks)

• It is taking a longer time to start-up;
• It is often hanging;
• Applications are taking longer to load.

 State three possible causes of these problems and how they can be solved (3mks)

4 a)Define authenticity as used in software selection  (1mk)

  b) List four ways of acquiring software in an organization     (2mks)

5 some of the storage disk available are:  zip disks, 3 ½ inch floppy disks, DVDs and 5 ¼ inch floppy disks. Arrange these devices in ascending order of storage capacity.    (2mks)

6.You have been asked to change your computer password. State a precaution you need to take in order to avoid each of the following:           

a) Forgetting the password     (1mk)

b) Hacking       (1mk)              

7.State four benefits of using a computer in a school library   (2 mks)

8. Using six bits, find the two’s complement of -2310.     (4 mks)

9. Explain data series, axis and legends as used in spreadsheet charts.  (3mks)

• Data

• Axis

• Legend                       

10. a) Describe the term data integrity.                                            (2 mks)

     b) State four situations in which data may lose integrity.           (2mks)

11.State the function of each of the following:

            a)Network interface card                                                           (1 mk)

            b)Network protocol                                                                    (1 mk)

           c)Hub                                                                                         (1mk)  

12. List four types of publications that can be designed by using desktop publishing software.   (2mks)

13. Differentiate between the following pair of terms as used in database design:

    a)  Input mask and design.                                                           (2 mks)

    b) Table and query                                                                      ( 2mks)

14. List four factors to be considered when purchasing an operating system.     (2mks)

15   Write an algorithm to compute the area of a triangle.   (2mks)

SECTION B (60 MARKS)

Answer question 16 and any other three questions from this section in the spaces provided

16. Study the flowchart below and answer the questions that follow

i) Name the control structures used in the flowchart                 (2mks)

ii) Determine the values of M, N, P and Q.                                ( 4 mks)

M………………………….. N………………………..

P ………………………….. Q ………………………

  iii) Write the pseudo code for the flowchart   (7mks)

 b)  List four functions of an assembler    (2 mks)

17. Define the following web related terms:       

 i)  Web browser   (1mk)

 ii)  Hyperlink      (1mk)

iii) Hypertext document                (1mk)

b)  List six activities performed on the web      (3mks)

c) An institution has ten stand alone computers

i)  Suggest with reasons the most appropriate topology required to inter-connect the computers.   (3mks)

ii) State the necessary steps required to connect the computers to the  internet.      (4mks)

d) Below is an email address:

Name the parts labeled:

                        i)

                        ii)

                        iii)

18.A computer C directory has folders for form 1, form 2, Form 3 and form 4.  Each class has student’s folders labeled according to their number.  The students create their own folder for the subject the are studying based on the table shown below

a)Assuming there is one student per class, draw the corresponding directory tree structure.  (6 mks)

b) i)  a form four student wants to create a folder to store her project. State the path for that project folder.(2 mks)

ii)Suggest how the student can ensure that:

                        1.         Work is not lost in case the hard disk fails.                (1mk)

                        2.         The project is not copied by other students.               (1mk)

c) i).  Other than I/O devices, list other three devices under the control of the operating system.                                                  (3mks)

 ii)Explain any one of the devices named in C (i) above            (1mk)

d)Define the term trouble shooting    (1mk)

19. A manager wishes to replace the current manual system with a computerized one

 a)Describe three main areas that must be evaluated to justify the  replacement   (6mks)

b) List the three areas that would be considered in the requirements specifications.      (3mks)

c)State and explain three ways that can be followed to replace the current system    (6mks)

20. a)  A head teacher keeps the following student details in a database:  Name, Address, Town, Date of Birth, Marks scored, Fees paid.

i)Name the most appropriate primary key. Give a reason      (2mks)

ii)For each item in the student’s details above, indicate its most appropriate data type as used in the database.           (3mks)

iii)Explain why input screens are better data entry designs than entering data directly to a table.        (2mks)

b)List two career opportunities associated with databases.       (2mks)

c)Distinguish between:

i) A table in a word-processing application and a table in a database application (2mks)

ii)Mouse pointer and insertion point.    (2mks)

d)Outline the steps to be followed in order to merge cells in a word processing table.    (2mks)

Advantages

• Sharing of software and data files
• Sharing of hardware, e.g. printers
• Communication

Disadvantages

• Security of files is more of a problem

(a) Phishing

• Phishing is a strategy that encourages a computer user to part with sensitive information such as bank details hence the term ‘phishing’ – i.e. fishing – trying to catch someone out. For example, a perpetrator sends a user an email that appears to be genuine, for example, pretending to be a bank or a lawyer requesting that the user verify bank account details or send money to assist in the completing of a legal case.

(b) DoS

• DoS is a means of attack on a specific user/system/website which involves overloading a target with too much network traffic resulting in system slowdown, shutdown or a violation of security.

Uses transistors( resistors and capacitors) . It can be implemented by the use of NAND or NOR gates. Data is stored on the chip as a charge

A computer keyboard is an input device used to enter text, characters, and various commands into a computer or other digital devices.

• Physical topology deals with the placement of nodes
• Logical topology deals with the data flow  in the network

i) To manage the execution of instructions
By running a clock
To decode instructions
(ii) To store OS
To store those parts of applications programs currently running
To store data currently in use
(iii) Part of the processor where data is processed/manipulated
All I/O must pass through here

• Commandline/ Character interface Operating systems
•  Menu Driven Operating Systems
•  Graphical User Interface Operating Systems

Windows for example a word processing application and a spreadsheet
 
Menus, for example, allow the user to perform operations or run applications such as right-click to create a new folder  
 
Icons for example a picture of linked computers for networking
 
Pointers(mouse or touchscreen)  for example to select items/trigger events  
 
Shortcuts for example to frequently used applications for example having a shortcut to your mail client on your desktop
 
File navigation for example when searching the hard disc for a file/folder using a browser
 
copying / deleting / moving/sorting/naming/searching of files or folders for example copying of a file from the hard drive to a USB pen drive (File handling)
 
Desktop customisation for example changing the colours and background image
 
Copy and paste for example between applications e.g. copying a graph from a spreadsheet to a word processor
 
Error messages for example provide users with error/warning/help messages for example ‘printer out of paper’ 

• No licence agreement as a certificate of authenticity
• Prices that are extremely cheap
• No documentation manual
• when one connects to the internet for authentication, the report from the manufacturer indicates that the user may be a victim of software counterfeiting
• frequent runtime or occurrence of fatal errors when using the machine