• System software manages the computer hardware/application software
• application software is for end-user tasks

• the pain felt in muscles, nerves and tendons caused by repetitive movement and overuse.
• Injury as a result of repetitive use of parts of the body while performing work
• Strains and injuries due to prolonged typing and use of the mouse

• Access Controls: Authentication of users in order to access files
• Performing regular patches of updates
• creating secure accounts with required privileges
• scrutinizes all incoming and outgoing packets of data through a firewall
• encryption of data, during transmission
• Log files to detect any breach

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

System Stability: Computers require a consistent and stable power supply to function properly. Fluctuations or interruptions in the power source can cause various issues that can disrupt the computer's operation or lead to hardware damage.

a. Data Loss: Sudden power outages or voltage fluctuations can cause the computer to shut down abruptly, resulting in data loss if unsaved work is not properly stored. This can be particularly problematic when working on critical tasks or handling important files.

b. Hardware Damage: Power surges or inconsistent power supply can damage the computer's internal components, including the motherboard, CPU, memory, and storage devices. These damages can result in system instability, reduced performance, or even complete hardware failure.

c. Operating System Corruption: Abrupt power loss or inconsistent power supply can corrupt the operating system files, leading to system crashes, error messages, and instability. This may require system repairs or reinstallation of the operating system.

d. Component Lifespan: Inconsistent power supply can put unnecessary stress on computer components, shortening their lifespan. Frequent power fluctuations or surges can cause wear and tear on various parts, reducing their efficiency and overall longevity.

1. Ergonomic Chair: Ensure that each user has an ergonomic chair that provides proper lumbar support. The chair should be adjustable in terms of height and backrest angle.

2. Adjustable Desk: Provide adjustable desks or workstations that can accommodate different user heights and allow for proper positioning of the keyboard, mouse, and monitor.

3. Monitor Placement: Ensure that the computer monitors are positioned at eye level or slightly below to prevent users from straining their necks and shoulders. Consider using monitor stands or adjustable monitor arms for better positioning.

4. Keyboard and Mouse: Encourage the use of ergonomic keyboards and mice that are designed to minimize strain on the wrists and hands. Provide wrist rests if needed.

5. Proper Lighting: Ensure that the computer room is well-lit, with appropriate lighting levels to reduce eye strain. Avoid glare on the computer screens by using adjustable blinds or curtains.

6. Regular Breaks: Encourage users to take regular breaks from prolonged computer use. Suggest the 20-20-20 rule: Every 20 minutes, look away from the screen at an object 20 feet away for at least 20 seconds.

7. Stretching Exercises: Promote stretching exercises for the neck, shoulders, and back to help alleviate muscle tension and improve blood circulation. Display posters or provide resources on desk stretches and exercises.

8. Correct Posture: Educate users about proper sitting posture, emphasizing the importance of maintaining a neutral spine position. Provide visual aids or ergonomic training materials to demonstrate the correct posture.

9. Desk Organization: Encourage users to keep their workstations organized to minimize the need for reaching or straining. This includes keeping frequently used items within easy reach and arranging cables to prevent trip hazards.

10. Individual Assessments: If the backache issue persists, consider offering individual ergonomic assessments for users. A specialist can evaluate the user's workstation setup and suggest personalized recommendations.

Serial

• -more accurate/fewer errors over a longer distance
• -less expensive wiring  
• less chance of data being skewed/out of synchronization/order

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

• Sequential
• Random
• Serial
• Indexed-sequential

– when transferring large files/attachments with emails
– when streaming music/video files/bit streaming
– when using VoIP/video conferencing
– software updates
– online transactions
– Using VLE (Virtual Learning Environment)

a)Spreadsheets                                                                                                                               (2mks)

• Microsoft Excel
• Lotus 1-2-3
• Google Sheets
• OpenOffice Calc

                                           Any 2 @ 1mk

b) Word processors                                                                                                                          (2mks)

• Microsoft Word
• Wordpad
• Corel WordPerfect
• Lotus Word Pro

                                         Any 2 @ 1mk

• The preparation of a system proposal which lists the problem definition, objectives of the study, terms of reference of study, constraints, and expected benefits of the new system, in light of the user requirements

– faster communications now widely available
– safety reasons, e.g. increase in terrorist attacks on international flights
– reduced transportation/accommodation/hardware costs
– environmental issues, e.g. reduced carbon footprint
– increase in multinational working

(i) Crop - used when handling a graphic and there is a need to remove some of the portions in the graphic

(ii)Transparency - used when there is a need to make background of a graphic visible

• Software may be designed to run on 1 core and not multiple cores
• depends on the task(s)  i.e some tasks cannot be split across cores
• Clock speed also affects speed i.e dual core may have a faster clock speed and quad-core may have slower clock speed so one task may be run faster/slower
• RAM size also affects speed i.e Quad-core may have less RAM  amount of VM being used
• Cache size also affects speed i.e Quad-core may have less cache

Multi-tasking - It is a data processing modes where a single CPU processing more than one task or program apparently at the same time

Time-sharing - a processing mode where a single CPU processes tasks from more than one user apparently at the same time

Time-sharing - this is a processing mode in which the CPU serves two or more users with different processing requirements ( tasks)

On-line processing - is a mode of processing where the result of data processing transaction is available immediately

Real-time processing - is a mode of data processing in which the time interval required to process and respond to inputs is so small that the response itself is useful for controlling the physical activity of a process

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