• Ease of installation and use
• Application software intended for use in the computer
• Processor type. Some processors do not support all operating systems

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

• All the characters and symbols that can be represented by a computer system.
• Each character and symbol is assigned a unique value.

(b) One disadvantage of using the Unicode character set, instead of the ASCII character set, is

that the text stored takes up more storage space

• Each character is encoded using more bits

• A compiled program will only execute on a processor of specific type/family/with same instruction set
• A program run using an interpreter can execute on a computer with any type of processor;

• Is the protection of programs and data in computers and communications systems against unauthorized modification, access or disclosure
•  

There could be several possible causes for the issues Jane is experiencing with her computer keyboard, including:

1. Software Issues
   - Cause: Outdated or corrupt system files, drivers, or operating system.
   - Solution:
     - Ensure the operating system and drivers are up-to-date.
     - Run a system file checker to repair any corrupted system files (e.g., on Windows, run "sfc /scannow" from the Command Prompt).
     - Consider reinstalling the operating system if issues persist.

2. Hardware Issues:
   - Cause: Physical damage or malfunction in the keyboard hardware.
   - Solution:
     - Check for physical damage or debris under the keys and clean the keyboard if necessary.
     - If cleaning doesn't help, consider replacing the keyboard with a new one.

3. Resource Overload:
   - Cause: The computer may be running too many background processes or lacking sufficient hardware resources.
   - Solution:
     - Close unnecessary background applications and processes to free up system resources.
     - Consider upgrading the computer's RAM, CPU, or storage if it's outdated and unable to handle current software demands.
     - Use task manager or activity monitor to identify and terminate resource-intensive processes.

4. Malware or Viruses:
   - Cause: Malicious software can slow down a computer, cause hanging, and delay startup.
   - Solution:
     - Perform a full system scan using reputable antivirus or anti-malware software to remove any threats.
     - Ensure that the operating system's security patches are up-to-date.

5. Disk Fragmentation:
   - Cause: Fragmented files can slow down the loading of applications and overall system performance.
   - Solution:
     - Run a disk defragmentation tool (e.g., Windows' built-in tool) to optimize file storage on the hard drive.
     - Consider upgrading to a solid-state drive (SSD) for faster application loading times.

6. Insufficient Storage:
   - Cause: If the hard drive is nearly full, it can cause slow performance.
   - Solution:
     - Free up space by deleting unnecessary files and programs.
     - Consider upgrading to a larger capacity hard drive or SSD if storage space remains an issue.

7. Background Processes and Startup Items:
   - Cause: Too many unnecessary programs running in the background or starting up with the computer.
   - Solution:
     - Disable or remove unnecessary startup items and background processes to improve startup time.
     - Use the Task Manager or System Preferences (on macOS) to manage startup items.

It's important to diagnose the specific cause of the issues Jane is facing by troubleshooting each potential problem one by one. In some cases, a combination of these solutions may be necessary to fully resolve the problems with her computer keyboard.

device: beeper/loud speaker
use: to indicate barcode correctly read/error in reading barcode
device: (LCD) screen/monitor
use: to show prices and other information about goods
device: touch screen
use: to show prices and other information about goods/to select items that need to be
weighed/identified
device: weighing machine
use: to find weight of loose items (e.g. fruit) to enable pricing
device: (magnetic) card reader/CHIP and PIN reader
use: to read customer’s debit/credit card/enable customer to pay for goods using a
credit or debit card
device: printer
use: to print receipts

• All nodes ‘listen’ for traffic to sense when the network is idle.
• When a node wishes to transmit, it transmits a ‘request to send’ frame’ (RTS)
• The intended receiving device will transmit a ‘clear to send’ (CTS) frame if it is available.
• All other nodes ‘sense’ the network is busy and wait a random amount of time before trying to transmit

Describe how the computer on board the aeroplane uses GPS to find its exact location

– satellites transmit signals to onboard computers
– computers receive/interpret these signals
– system depends on very accurate timing/use of atomic clocks
– each satellite transmits data indicating location and time
– computer in aeroplane calculates location based on at least three satellites
– at least 24 satellites in operation at any one time
– position accurate to within one metre
– can also calculate altitude of aeroplane
– ref to “triangulation”:

Give two benefits of using GPS in this application

– safer as the known location is exact/more accurate
– reduces the possibility of pilot error
– allows accurate estimation of arrival time
– display and guide the pilot to the nearest airport in case of emergency

Twisted pair cables

Coaxial cables

Fibre optic cables

• The users may not have gained enough confidence to run the new system
• It may be very inconveniencing in case the new system fails or faces problems
• The weaknesses of the old system may not be corrected or may still be transferred to the new system

• Data Integrity: they provide ways or mechanisms for enforcing data integrity constraints, such as referential integrity. If a record in the parent table is deleted, related records in the child table also get deleted. This ensures accurthe acy and consistency of data stored in the database
• Data Security
• Concurrency control
• Reduces data redundancy
• Data retrieval and querying
• Data indexing
• Data consistency and acid transaction
• Data backup and recovery
• Data sharing and collaboration
• Convenient data maintenance

• Overtype mode: deletes the current text at the cursor position and replaces the existing characters with new text
• Insert Mode: pushes the existing text away as new text is inserted between the existing text

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.

• To get the latest features
• To update security features

• Recommendation on whether to continue or abandon the project
• Methods used to collect data
• benefits and limitations expected
• the technology required to develop and maintain the project
• Installation and running cost
• Time limit

• car factories/factories
• chemical/nuclear factories
• production lines
• warehouses
• deep in the ocean/down mines
• on other planets/in space
• road junctions

Virus / trojan / worm / malware

• Piece of software/code/a program that replicates itself  or causes damage e.g. editing/deleting files

Prevention

• Running anti-virus/anti-malware software 
• don’t download from unknown sources
• don’t click on unknown links

Spyware / malware / keylogger

• Piece of software/code/a program that records actions/key presses and sends this data to a third party analysis

Prevention

•  Running anti-spyware/anti-malware software/firewall

Data interception / passive

• Data is sent to another device and is intercepted by a third party

Prevention

• Encryption

Phishing

• An e-mail has a link that when clicked directs the user to a fake website that collects personal data

Prevention

• Network policy // firewall

Pharming

• A piece of code installed that redirects user to fake website that collects personal data

Prevention

• Anti-malware or firewall

Hacker

• Person attempting to gain unauthorised access to the network/computers/ data/files 
• unauthorised access and then deleting/editing data/files

Prevention

• Firewall
• strong password 
• biometrics
• penetration testing

1. SECTION A
2.  Answer all questions in this section
3. What is a computer?                                                                                                            1mks
4. State three physical components that make up a computer                                                 3mks
5. State the hardware technological differences between the second generation and third generation computers                                                                                                          2mks
6. State and explain three characteristics of a computer                                                         3mks
7. State the functions of the following special memories in a computer                                3mks
8. Buffers
9.  
10. Registers
11. Cache
12.  
13. Define the following as used in data representation in a computer                                  (5mks)
14. Bit
15.  
16.  
17. Byte
18.  
19.  
20. Nibble
21.  
22.  
23.  
24. Word
25.  
26.  
27.  
28. Word-length
29.  
30.  
31. State two reasons why a DVD is superior to a typical compact disk                               (2mks)
32. State three advantages of flat panel monitors over cathode ray tube monitors                   3mks
33. Explain the following terms as used in word processing                                                  3mks
34. Section breaks
35. Thesaurus
36. Superscript
37. State two advantages of  impact printers                                                                             2mks
38. State the function of the following keys on the computer keyboard                                  3mks
39. Enter key
40. Insert key
41. Delete key
42. State the technology used by the following secondary devices to store data                      3mks
43. Magnetic storage devices
44. Solid state storage devices
45. Optical storage devices
46. State three reasons why an operating system is important in a computer                         3mks
47. A typical computer’s main memory consists of both volatile and non-volatile memory.
48. i)  Explain what is meant by the term volatile memory                                          (1mark)
49. ii) What is normally stored in the non-volatile part of a computer’s main memory (1mark)
50. Explain why having cache memory can improve the performance of the CPU         (2mks)
51. What is a computer system?                                                                                           (1mk
52. Give two differences between a solid state drive (SSD) and a hard disk drive (HDD)   2mks
53. State three categories of software classified according User license agreement              (3mks)
54. State two disadvantages of Random Access Memory                                                       (1mk)
55.  
56.  
57. a) Explain the functions performed by the following components of a processor   (2 marks)
58. Control unit