Definition

• Disk formatting is the process of preparing a data storage media for initial use

Reasons:

• To make a disk blank for reuse
• To make it compatible with another operating system
• to create tracks and sectors for first time use

(a) Cookies

• Information that a website stores about a user on their hard disk; this enables
  the website to remember details about the user when they next visit the website.

(b) Spyware

• Program installed on a PC to gather information about the user. It monitors
  every key press and relays the information back to the home base

(c) Phishing

• Sending an email that claims to be from a legitimate company; the recipient is then directed to a bogus website where their personal details will be collected

(d)Spam

• Junk/ (unsolicited) electronic mail advertising products and services sent to a general mailing list.

(e) Pharming

• Malicious code installed on a PC or on a server. This code directs users to a
  a fraudulent website without their knowledge.

• 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

– if one station/cable fails, others are not affected
– easier to identify faults when using star topologies
– it is easier to expand this type of network
– performance doesn’t deteriorate under load

• Better/improved traffic flow control
• reduces accidents
• keeps delays to a minimum
• reduces pollution
• cars use less fuel

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

• she had actually described verification
• data could be incorrect, therefore same incorrect data typed in twice
• accept description of validation process e.g. range check

• 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 parent can) set criteria for the websites she is allowed to visit such as a whitelist/blacklist of websites. The firewall will examine the data/traffic incoming and outgoing from her computer. If data is sent from a website that is not allowed, it will be blocked

Taking a four-digit 0  binary number i.e (0000)2

In ones complement this is  1111

In twos complement this becomes 1111+1= 0000

So, It is clear that 0 and negative zero is the same in twos complement while in ones complement they are two different values

Benefits

• The user is not restricted to the predetermined options//the GUI uses icons and set menus
• The user has more control over the computer settings//in GUI computer settings are protected from the user
• Uses less memory than GUI
• Requires less processing power for the interface
• More processing power is made available for the task

Drawbacks

• The commands used have to be learnt
• The commands used have to be remembered
• The commands used have to be typed in/entered exactly
• Have to remember the exact path/correct name of application
• More prone to errors on data entry Commands have to be typed in//in a GUI can use touchscreens/mice
• Tends to be used by specialist people//GUI is more user-friendly and can be used by non-experts

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 the user to run programs 

• On a multitasking operating system, it ensures that all tasks appear to run simultaneously 

Other roles

• Allocates time slices
• Scheduling of programs
• Handles interrupts
• Allows the user to configure hardware

• Because data is recorded to the disks once but can be accessed many times without changing the content
• once data is written to the disk, it becomes read-only and cannot be altered or erased.

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

• StudentID: String
• FirstName: Required 1
• Year: 2 1
• Email: Email address containing @ sign 1
• AccountBalance: Real

The data before encryption is known as .......plain.................. text.
To scramble the data, an encryption ......................key.........................., which is a type
of ...................key............................, is used.
The data after encryption is known as ....................cipher............................. text.
Encryption prevents the data from being ......................understood...................... by a hacker

b) What Simeon and Anna said about the life of Jesus during the dedication. (7mks)

Jesus would save people

He would bring glory to Israel

He would be a light to the gentiles

He would be a universal savoir

He would bring judgment to the Israelites

Many people would oppose his work

He would reveal secret thoughts of people

He would be the source of redemption for Jerusalem

Virus

• - program/software that replicates/copies itself
• – can delete or alter files/data stored on a computer
•  – can make the computer “crash”/run slow

Pharming -

• malicious code/software installed on a user’s hard drive/actual webserver
•  – this code redirects user to a fake website (without their knowledge)
•  – to obtain personal/financial information/data

Phishing

• - legitimate-looking emails sent to a user
• – as soon as the recipient opens/clicks on the link in the email/attachment …
• – … the user is directed to a fake website (without their knowledge)
• – To obtain personal/financial information/data

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

• 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