State what is meant by real time
- Real time OS provides a guaranteed response time
Explain why a Real time OS would be suitable for Intensive Care Units
- Responses are immediate if something happens to a patient whereas other systems may have a delay in response.
Explain why a First Come First Served scheduling method may not be efficient
- Once a job starts it stops other jobs from being processed
- A job using a slow resource wastes processor time like a printer
Explain why scheduling is necessary
- Scheduling is necessary as it processes as many jobs as possible quickly in a fair manner with fast response times and makes most efficient use of the processor
Describe what is meant by the term BIOS
- BIOS tests if hardware components are working and boots up the operating system
Why is First Come First Served suitable
- Each job has the same processing time and is treated equally
Describe one difference between paging and segmentation
- Paging splits up memory into 4k fixed sizes whereas segmentation splits up memory into sizes that vary
- Paging uses physical addressing but segmentation uses logical addressing
Why would removing an external hard disk drive need to interrupt the FDE cycle
- The operating system will need to remove open files
Describe how a stack is used when handling interrupts
- A stack uses FILO storage and the processed halted by the ISR are pushed on the stack
Explain what is meant by the term device driver
- A program that controls a piece of hardware providing a user interface
Why is a star network topology useful?
- Faster communication as the switch acts as a central point which all communications are passed
- If security is installed centrally it will be automatically installed in all other devices
Define what is meant by a layer
- A layer routes packets of data back and forth between different networks
Adv & Disadv of storing data in cloud
Adv:
- Cloud has more security as it’s updated frequently
- Accessible on any device as long as it’s connected to the internet
Disasv:
- Access to data depends on internet connection, serves down means no access
- Costly
Describe two software based security methods companies can use to protect data
- A firewall can be used to filter packets coming in and out of the system and if a packet is suspicious it’s reported or rejected.
- An antivirus is used as it prevents viruses from capturing internal data which can be downloaded online
HTML
To insert an image use:
<img src = “_______” >
To insert a link use:
< a href = “_____” > ____ </a>
To write an unordered list use:
<ul>
<li>”\_\_\_\_\_\_\_\_\_”</li>
</ul>
To write an ordered list use:
<ol>
<li>”\_\_\_\_\_\_\_\_”</li>
</ol>
Explain what happens when a search engine indexes the page
- A program called a spider traverses the web following link and takes each word in the document adding an entry for the page and index alongside the word’s position on the page
Describe the Rapid Application Development process
- A prototype is created and feedback is used to inform the next iteration where any changes are made
CSS
Text {
Color:”__”;
Variable:”__”;
}
Explain how linkers are used during the compilation process
- The main program is linked to libraries and can either include them in the final code or get executable code to point to external libraries
Advantages of a LAN
- Files can be shared on a local network
- Files can be access by nearby devices
- Files can be printed to shared printers
Advantages of a WAN
- Centralised security point
- Users can share resources
- Covers a large geographical area increasing communication over large distances
Explain the differences between a flat file and relational database
- A flat file may have redundant data and is harder to update but a relational database has more security and linked tables
Describe what is meant by a utility
- A utility performs a specific task for example a virus checker
Waterfall lifecycle
- A linear development model where one phase ends and the next begins
- Cannot revisit old stages
- Not suited for projects that require change
- User involvement is limited and is used for low risk projects
