• It sends control signals that manage the transfer of data and instructions within the CPU
• It decodes an instruction using an instruction set

Direct Change-Over

• A date is chosen for the shutdown of the old system, then at that time, the old system
  is turned off and the new system is implemented

Phased

• Parts of the new system are implemented in stages or for a period of time, both the old and the new system are running together until all parts of the system are implemented.

– software that can be used to design new products/amend existing products
– makes use of features such as 2D, 3D, wire frames, library of parts, links to CAM

Give three different applications that make use of CAD.

– aerospace
– architecture
– designing cars
– designing consumer goods
– chemical/nuclear plant design
– designing electronic circuit boards
– ergonomic design
– landscape/garden design

Name three specialist input/output devices used in CAD.

– large monitor/screen with hi-res
– touch screen
– plotter
– space mouse/space ball/4D device
– 3D glasses (in some applications)
– light pen
– graphics tablet
– 3D printer
– 3D scanner

Trojan (horse); a program which misleads the user into thinking it is another

piece of software which, when run, executes another program;

Spyware; a program which records data such as usernames and passwords on

a host system and forwards the information to a third party;

Adware; code embedded or attached to program files which will persistently

show adverts (that attempt to generate revenue);

Worm; code which will run autonomously and replicates itself on a host system;

Ransomware; a program that encrypts user’s data to make it unreadable until

they pay for the key;

Remote Access Tool (RAT); allows access to control and monitor a computer

from a remote network location;

Rootkit; malware that has managed to gain ‘root’ admin privileges;

Bots/Zombies; a program installed on a computer that performs a job for the

remote owner of the bot/zombie such as sending spam or sending web requests

to perform a DOS or attacking a computer system;

Scareware; malware that tells you something is wrong with your system in an

attempt to get you to make a purchase;

Keylogger; a program that monitors/records a user’s keystrokes in order to steal

passwords/confidential details;

Sequence: Sequential execution of a program one line after another

Selection:  Involve the a decision between two or more options e.g  if...then...else

Loops/Repetitions: Used for looping i.e a line of code can be made to execute a given number times before terminating.

RAID (Redundant Array of Independent Disks) technology refers to a method of combining multiple physical disk drives into a logical unit to improve performance, data availability, and data redundancy. RAID technology is commonly used in storage systems to provide fault tolerance, data protection, and increased storage performance.

The primary purpose of RAID is to create a more reliable and robust storage solution by spreading data across multiple drives and implementing various data redundancy techniques. This helps to mitigate the risk of data loss and system downtime in case of drive failures.

There are different levels or configurations of RAID, each offering different features and trade-offs. The most commonly used RAID levels are:

1. RAID 0 (Striping): Data is split evenly across multiple drives, resulting in increased performance as data can be accessed from multiple drives simultaneously. However, there is no redundancy, so if one drive fails, data loss can occur.

2. RAID 1 (Mirroring): Data is duplicated or mirrored across two drives, providing redundancy. If one drive fails, the other drive can still function and serve the data. RAID 1 offers data protection but does not offer increased performance.

3. RAID 5 (Striping with Parity): Data and parity information are striped across multiple drives, providing both increased performance and fault tolerance. Parity information allows for the recovery of data in case of a single drive failure. RAID 5 requires a minimum of three drives.

4. RAID 10 (Combination of Mirroring and Striping): RAID 10 combines elements of RAID 1 and RAID 0. It involves mirroring data across two sets of drives and then striping the mirrored sets for increased performance and fault tolerance. RAID 10 provides high levels of data redundancy and performance but requires a minimum of four drives.

Syntax error

• An error in the source code of a program like pront("Hello, " + name) instead of print
• These are errors that emanate from improper use of language rules such as spelling mistakes,improper use of variables and misuse of reserved words

Logical error

• A mistake in a program's source code that results in incorrect or unexpected behaviour like if age == 65: print("Eligible for a discount.") instead of using if age >= 65: print("Eligible for a discount.")
• These are errors that occur due to imperfect comparisons

Run-time error

• An error which occurs when a program is asked to do something that it cannot, resulting in a ' crash'9. For example, asking a number to be divided by 0 such as 72/0.
• An error that results in a sudden halt of an executing program

• College authorities are the experts in the problem
• A system Analyst is an expert with computers
• The two need to pool resources to come up with a clear definition
• Agree on the outcomes so that when the system is , there are a set of criteria to judge it by

• Bus topology is characterised by common transmission media shared by all the connected nodes
• Star topology is characterised by a central switching node connected directly to each of the multiple nodes in the network

Advantages of Star topology over Bus topology

• Faster communication as compared to bus topology
• Independent line of connection allows freedom of removing or adding nodes

Disadvantages of Star topology over Bus topology

• Expensive as compared to the bus topology
• Long cable length

Transcription Errors: Transcription errors involve the incorrect entry of data due to mistakes made during the copying or typing process. These errors can occur when transferring information from one source to another.

Transposition Errors: Transposition errors specifically refer to errors where the order of characters or digits is accidentally reversed or swapped. This can happen during manual data entry or when processing information.

Serial

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

Program counter // PC
• Stores the address of the next instruction to be fetched
Memory address register // MAR
• Stores the address where data/instruction is to be read from or saved to
Memory data register // MDR
• Stores data that is about to be written to memory // Stores data that has just been read from memory
Current instruction register // CIR
• Stores the instruction that is currently being decoded/executed

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)

• star - if one computer goes down the others can still be used
• ring - if one computer goes down the others can not be used

• mirrored hard disk/hot standby/second computer
• re-run the old master file with the transaction file

• connecting wireless headphone to a phone
• Using a wireless mouse, keyboard etc
•  

• Network
• Commercial
• Enterprise
• Proprietary

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

• ICT provides graphic design tools that allow marketers to create visual content for ads , websites and even social media
• computers enable marketers to produce video content crucial for modern digital marketing using video editing tools 
• Computers are used to distribute and analyze online survey polls  that help in understanding customer preferences
• Social media platforms offer ad placement based on user demographics and interest
• Online marketing
• Social media marketing
• Target marketing
• Email marketing
• Blogging

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