• Commandline/ Character interface Operating systems
•  Menu Driven Operating Systems
•  Graphical User Interface Operating Systems

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

Legend

• Legends are a small visual representation of the chart's data series to understand each without confusion.

A data series

• is a row or column of numbers that are entered in a worksheet and plotted in your chart, such as a list of quarterly business profits
• A group of related data points or markers that are plotted in charts and graphs

Data Marker

• A symbol on the chart that represents a single value in the worksheet.
• A column, dot, pie slice, or another symbol in the chart that represents a data value

• do not allow outside floppy disks/CD’s/DVD’s
• use disk free work stations
• download/install and use anti virus software
• scan hard disks regularly
• update the anti virus program regularly
• do not open file attachments from unknown sources/download
• doubtful software from the Internet
• do not use files that come from unknown sources
• buy original software/do not buy pirated software
• use firewalls

1. Slow Performance: If your computer suddenly becomes significantly slower than usual, taking longer to boot up, open applications, or respond to commands, it could be a sign of a virus. Viruses can consume system resources, resulting in decreased performance.

2. Frequent Crashes: If your computer frequently crashes, freezes, or experiences sudden system reboots without any apparent reason, it could be due to a virus. Some viruses can interfere with system stability, leading to unexpected crashes or instability.

3. Unusual Pop-ups or Ads: If you start noticing an excessive number of pop-ups, advertisements, or banners appearing on your computer screen, especially when you're not browsing the internet, it might be an indication of adware or malware infection.

4. Unwanted Modifications: Viruses can modify system settings or configurations without your consent. If you observe changes in your default browser homepage, new toolbars appearing, unfamiliar icons on the desktop, or altered settings, it could be a sign of a virus.

5. Unusual Network Activity: If you notice excessive network traffic, unusual data transfers, or a sudden increase in data usage without any known reason, it could be an indication of a virus or malware actively communicating with external servers.

6. Missing or Modified Files: Viruses can delete, encrypt, or modify files on your computer. If you find missing files or encounter unexpected changes in file sizes, names, or extensions, it could be a result of a virus infection.

7. Disabled Security Software: Some viruses attempt to disable or circumvent antivirus or security software to avoid detection. If you notice that your antivirus program or firewall is deactivated, modified, or unable to update, it could be due to a virus compromising your security software.

8. Unexpected Email or Message Activity: Viruses can use infected computers to send spam emails or messages to contacts in your address book without your knowledge. If your friends or colleagues report receiving suspicious or unexpected emails or messages from you, it could be a sign of a virus.

• data must be accurate/up-to-date
• personal data must be registered
• data must be used for the purpose that is registered for
• if data is to be used for another purpose the registrar must be notified/
• subject gives consent
• patients must be able to see the data and have it changed if it is incorrect
• processed fairly and lawfully
• kept no longer than needed
• kept secure
• not transferred to other countries without protection

Convert the HTML into a webpage which is rendered on the screen

• it generates and/or allocates an IP address

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

• memory used up/slows down computer/alters setting/systems failure
• erases files/erases data/corrupts data/data needs restoring
• infects other computers on the network
• production loss/financial loss

(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

• hexadecimal is easier (for humans) to read (than binary);
• numbers are displayed in a more compact way (in hexadecimal than in binary);
• it is quicker to type in (hexadecimal numbers than binary numbers);
• it reduces the risk of typing errors (in hexadecimal numbers than binary numbers);

• The process of rewriting parts of a file to contiguous sectors on a disk

• when designing a database a data dictionary provides the description and purpose of the fields/attributes of the database table(s). For example the field name (i.e. “phone number”), the data type (text); the size of the field (10) etc.

• 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

– multiple choice/yes-no answers
– easy to understand interface e.g. use of icons/drop down menus etc.
– output shown as % probabilities of fault

Responsibilities of the software developer is to ensure that the ergonomics focuses on making software user-friendly, reduces repetitive motions or eyestrain and enables movements of users to promote comfort and efficiency.

Software can be designed with adjustable text sizes and screen brightness settings to prevent eye strain, offering users a way to customise their visual experience for better comfort during prolonged use.

emails: – fast delivery of messages (to recipient’s mail box)
– able to send attachments
– can store messages for later use
– auto-translation no language problems
– can open email at a convenient time
video conferencing/calling/chat:
– removes need to travel (saves time and money)
– allows face to face discussions
– works in real time (only allow once)
VoIP: – much cheaper than normal international calls
– direct communication between people
– works in real time (only allow once)
chat rooms/instant messaging:
– instantaneous reply
– anyone can join in
social networking:
– can ensure only your “friends” are in communication
– usually free to join and use
– talk to (multiple) friends at the same time

• Resizing using resize handles
• Rotating
• Cropping
• Flipping
• Moving