• Main document
• Data source
• merged document

• it is a format style that shows the listed items of different levels rather than at one level. Each level has a different indentation and numbering style

1. Chapter 1

     1.1. Introduction

                 1.1.1.Definition of terms

The booting process is the sequence of events that occur when a computer is turned on or restarted. It involves a series of steps that allow the computer's operating system to initialize and become functional. Here's a simplified explanation of what happens during the booting process:

1. Power-On Self-Test (POST): When the computer is powered on, the first thing it does is perform a Power-On Self-Test. During this step, the computer's hardware components, such as the CPU, memory, and storage devices, are checked for proper functioning. The POST verifies that all essential hardware components are present and operational.

2. Bootloader: Once the POST is completed, the computer looks for the bootloader. The bootloader is a small program stored in the computer's firmware or on the bootable device (such as the hard drive or a USB drive). It is responsible for loading the operating system.

3. Loading the Operating System: The bootloader locates the operating system's files and initiates the loading process. It may display a boot menu allowing the user to choose the operating system if multiple options are available. The selected operating system's core files are loaded into the computer's memory.

4. Kernel Initialization: The operating system's kernel, which is the central component responsible for managing system resources, is initialized. The kernel sets up essential components such as device drivers, memory management, and process management.

5. System Initialization: After the kernel is initialized, the operating system proceeds with system initialization. During this stage, various system services and processes are started, and hardware devices are initialized and configured. The operating system loads essential system files and prepares the environment for user interaction.

6. Login/Graphical Interface: Once the system initialization is complete, the user is presented with a login prompt or a graphical user interface (GUI). The user can then log in with their credentials or interact with the GUI to access the computer's functionalities.

• The different factors that can influence the performance of a network include: bandwidth, network design, data collisions, and excess broadcast traffic.
• The bandwidth can influence through the method of transmission and medium used

SECTION A (40 MARKS)

ANSWER ALL THE QUESTIONS IN THIS SECTION

1.Compare the two types of diskettes used in microcomputers in terms of physical size and densities.    (2mks)

2.Why is it necessary to have a UPS in a computer laboratory?  (2mks)

3 a) Explain what is meant by batch processing   (1mk)

   b) Give one advantage and one disadvantage of batch processing ( 2mks)

4. List any four high level programming languages  (2mks)

5.A 3 by 4 matrix M is to be added to another 3 by 4 matrix array N so as to give a third 3 by 4 matrix array P.  Using a high level programming language, write a program segment that assigns the sum of M and N to P.(4mks)

6. The first column in the table below contains the formulae as stored into the cell F10 of a spreadsheet.  Enter the formulae, as they would appear when copied to the cell M20 of the same spreadsheet.  (3mks)

7.  Give three advantages of separating data from the applications that use the data in database design. (3mks)

8.  Explain the impact of information on organizations in each of the following areas:  (2mks)

   a) Competition

   b) Pace of growth

9. a) List any four tasks that an electronic spreadsheet should be able to perform other than calculations  (2mks)

    b) Explain what is meant by automatic recalculation as used in a spreadsheet.(1 mk)

10. Describe the functions of the following computer hardware components:

   a)Mouse                     (2 ½  mks)

   b)Scanner.                   (1 ½ mks)

11. a)State two differences between Disk Operating System (DOS) and WINDOWS operating system.

 b. i) Define the term application software  (1mk)

     ii) Give one example of application software (1mk)

12. a)  Give one difference between internal and external commands in Disk Operating System.   (2mks)

      b)  Name two DOS commands that may be used for checking disk errors.  (2mks)

13. Explain how a paragraph can be moved from one place to another in word-processing. 2mks)

14.  Define the term structured programming. (2mks)

SECTION B (60MKS)

Answer question 15 and any other three questions from this section.

15.a)  What is meant by each of the following terms:

 i)   pseudocode        (1 ½ mks)

  ii)  Flowchart           (1 ½ mks)

b) a program is required to list the first 1000 numbers in the series:  2, 4, 6, 8,

10. Draw a flowchart and write a program that can be carried out this task.   (12 mks)

16. The following car details are to be entered in a database; make, date-of-manufacture, colour and cost.

 a) Prepare a suitable database structure showing field names and their field types   (5mks)

 b) Explain how you index the data such that cars of the same make and colours are together   (2mks)

 c)  Write a statement that can be used to select cars of the colour green        (2 mks)

 d) Give an instruction that would;

  i)select cars whose cost lie between 500,000/= and 1,000,000/=  (3 mks)

 ii)Determine the average cost of all cars         (3mks)

17.  a)The diagram below represents the essential features o a computer system. Study the diagram and answer the questions that follow:

i)Name the components (4mks)

            A

            B

            C

            D

ii) On the diagram above, indicate the direction of data flow using arrows.  (3mks)

b) Name the three types of buses in a computer system (3mks)

c) Explain how CPU registers may be used to carry out a basic calculation such as:2 + 7 = 9

d) Name two computers output devices. (1 Mark)

18. a)State three ways in which computer technology may affect employment patterns in organizations   (3mks)

b) State three ways in which computer technology may affect employment patterns in organizations (3mks)

c)Suggest three strategies that can be employed to manage resistance to change  (3mks)

d) Give three advantages of computerization in an organization.  (3mks)

19. a)In a computer based information system, state the purpose of the following files and give one example where such a file may be required in a school.                (8mks)

i) report file

ii)Back-up file

iii)Reference file

iv) Sort file

b) State three precautions that should be taken to ensure that diskettes are well stored.  (3 mks)

c)  Distinguish between “serial” and Indexed sequential” file organization methods.  (2mks)

d)  Distinguish between binary and octal number systems and give an example of each  (2mks)

1. Virus scanning / Anti-virus. Used to locate and delete viruses / scans and compares files with databases of known viruses.
2. Firewall: checks data packets / examines source address / filters out unexpected packets.
3. Back up. Copies data onto a separate storage device for use if the original data is lost or corrupted.

A manager wishes to replace the current manual system with a computerized one. Describe three areas that must be evaluated to justify the replacement  (6 marks)

• Technical feasibility

• Does the current technology suffice

• Economic feasibility

• Benefits outweigh costs/ whether the project is cost effective

• Schedule feasibility

• Can it be done within the schedule

Headache, back and neck pain may result from the use of computers. State how each of them can be minimized (2mks)

• Proper lighting
• Regular breaks
• Use of antiglare
• Correct position of the screen
• Ergonomic furniture

Students of a school intended to elect their school Captain by secret ballot.  State three ways in which computers can be used to improve the election process                           (3mks)

• Registrations of voters
• Voter identification
• Actual voting
• Tallying

Interviews

Advantages

• can gather specific information and additional information
• high response rate to questions
• The question can be rephrased to seek more clarification
• it is possible to win the confidence of the interviewee and get honest answers

Disadvantages

• time consuming
• responses to interview questions are subjective.
• the interviewee may not open up on some sensitive issues
•  

Questionnaire

Advantages

• easy to administer
• can be anonymous.

Disadvantages

• fixed (inflexible) design
• potential differences in understanding and interpretation.

• The user can access the source code  so, they can tailor the software to their needs and they can fix any bugs in it
• the source code could be studied for educational purposes
• The user can redistribute the software/program  but this must be done under the same terms as the original software

High level languages are used in situations when:

1. Speed of execution is not a critical factor, such as in office applications.
2. a programmer needs to use complex commands that perform complex tasks.
3. A programmer wants to make use of standardised library / sub routines.

Low level languages are used in situations when:

1. a program must execute quickly such as real time applications
2. a programmer needs to write code that interacts directly with the hardware, such as device drivers
3. a programmer needs to perform a specific command not available in a HL language.

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

Twisted pair cables

Coaxial cables

Fibre optic cables

Dual input of data

• Two inputs are compared by the system and any discrepancies are reported (and not stored.)
• Data input once, either printed out or checked on the screen and  errors corrected

 Rules are given to the processor

• Only accept A, B, C, D, E, F, G i.e Any other input rejected.

Drop-down list/radio buttons

• Provides only valid inputs, so no other validation is required

• Protection against Password-related Vulnerabilities: Traditional password-based authentication methods are vulnerable to various risks, such as weak passwords, password sharing, or password theft.
• Stronger Access Control: Biometric readers add an additional layer of access control to laptops. Even if someone gains physical possession of the laptop, they would still need the authorized user's biometric data to unlock it and access the data. This helps prevent unauthorized individuals from accessing sensitive information stored on the laptop,
• Audit Trail and Accountability: Biometric authentication systems often come with built-in logging and auditing capabilities. This means that each time someone accesses the laptop using their biometric data, it can be recorded and associated with a specific user. This creates an audit trail, allowing organizations to track and monitor access to laptops and establish accountability in case of any security incidents or breaches.

emails: – fast delivery of messages (to recipient’s mail box)
– able to send attachments
– can store messages for later use
– auto-translation no language problems
– can open email at a convenient time
video conferencing/calling/chat:
– removes need to travel (saves time and money)
– allows face to face discussions
– works in real time (only allow once)
VoIP: – much cheaper than normal international calls
– direct communication between people
– works in real time (only allow once)
chat rooms/instant messaging:
– instantaneous reply
– anyone can join in
social networking:
– can ensure only your “friends” are in communication
– usually free to join and use
– talk to (multiple) friends at the same time

State the characteristics of each of the following network topologies (KCSE COMPUTER STUDIES 2021 )

i) Mesh Topology  (2mks)

• a host/node is connected to one or multiple hosts
• a   host/node in point to point connection with every other host or a few hosts
• hosts/nodes in mesh topology also work as relays for other hosts which do not have point-to-point links

(ii) Ring Topology (2mks)

• each host/node connects exactly to two other hosts
• data travels around the ring in one direction through all intermediate hosts
• failure of any host results in the failure of the whole ring

A computer virus is a program designed to damage other programs or causes irregular behaviour in a computer system.

2.1.1 Explain the concept of open source in the context of FOSS. (2)

• Is a software whose source available and user can modify and redistribute

Give ONE example of a free operating system the company could install on a laptop. (1)

• Linux
• FreeBSD
• ReactOS
• Android
• ChromeOS
• OpenSolaris

2.1.3 State TWO disadvantages of using free open-source software.

• Lack of support
• Security risks
• Compatibility issues
• Hidden costs

• Font Formatting:

  • Font Style: You can change the font style (e.g., Arial, Times New Roman) for cell content.
  • Font Size: Adjust the size of the text within cells.
  • Bold, Italic, and Underline: Apply these formatting options to emphasize text.
  • Font Color: Change the color of the text.

• Cell Formatting:

  • Number Formats: Apply various number formats, such as currency, percentage, date, and time.
  • Cell Borders: Add or remove borders around cells or cell ranges.
  • Fill Color: Change the background color of cells.
  • Text Alignment: Control how text is aligned within cells (left, right, center, top, bottom).
  • Text Wrapping: Allow text to wrap within a cell if it's too long to fit in one line.