Open source : refers to software provided freely with its source code. The user can modify and redistribute the software.

Freeware: these are software that can be downloaded for free and distributed, buta  the source code is hidden and cannot be altered.

Shareware: is software that is available for free within a given trial period, after which it must be bought.

Proprietary: software made for commercial purposes. The source code is hidden, and it can only be used after paying for a licence.

Acme company needs to ensure that if they are reselling the drives they wipe the drive (this should be done regardless of the destruction of the drive) to the DoD standard.

• Disassemble the drive by pulling it apart the drive so that the data would not be accessed
• Destroy the metal disk either by drilling holes so it cannot be read
•  Encrypt drives with passwords that are not accessible
• Degaussing the hard drives
• Use specialized overwriting software

This would ensure that any software cannot be used to locate files.

Many components that go into computer systems are toxic and dangerous to the environment if released or disposed of inappropriately.
Heavy metals are used in batteries and circuits and these can pollute groundwater or kill animals if left exposed on landfill. Large quantities of plastics are used in systems, which take a long time to break down, some of the plastic will eventually break down into toxins as it degrades.

Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common

Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again

Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.

Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.

Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations

Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.

• Computer systems use binary/ones and zeros/voltage on or off;
• Sound is analogue/continuous;
• Computers use digital data/discrete values

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)

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)

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.

        Misreading error

A PAN exist around a single person whereas a LAN covers a larger area

• 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.

• 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.

• Making prosthetic limbs for patients
• Making items which allow precise reconstructive surgery
• Making light-weight plane wings
• Making sculptures

• A computer is an electronic device that operates (works) under the control of programs stored in its own memory unit
• An electronic device that accepts data, as input and transforms it under the influence of a set of special instructions called programs, to produce the desired output (referred to as information)

• Sequential processing occurs in the order that the tasks are received while distributed processing where more than one computer or CPU is used to run specific programs.

• Developing training materials
• Training computer users
• Conducting ICT examinations
• Managing the learning and examination process
• Developing guidelines for using the computer lab
• Planning the course content
•  

Advantages of  of Hard Disk Drive

• Hard disk drives are cheaper per gigabyte than solid state drives.
• Hard disks have a longer lifespan than solid state drives

Disadvantages of Hard Disk Drives

• Consumes more power than SDD
• They are noisy.
• They are slower than solid state drives.
• They are susceptible to wear and tear as they have movable parts.

Advantages of Solid State Drives

• Are faster than HDDs
• It is more durable as it does not have moving parts
• Consumes less power
• Are not noisy

Disadvantages of SDD

• It costs more than a conventional hard disk
• Have fewer write/erase cycles compared to a hard disk drive
• Lost data cannot not be recovered

Manages memory (RAM) 

• Allocates memory to programs currently executing •

Ensures programs/data do not corrupt each other: Ensures all programs and data including itself is stored in correct memory locations

Manages processes: Ensures different processes can utilise the CPU and do not interfere with each other or crash •

Allows a user to run programs : On a multi-tasking O/S ensure that all tasks appear to run simultaneously

• Allocates time slices 
• Scheduling of programs
• Handles interrupt
• Allows a user to configure hardware

Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition

Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers

• Realtime processing
• Batch processing
• Timesharing
• multiprogramming
• Online
• Batch
• Distributed