System Software

• What is the purpose of secondary storage in a computer?

  It stores software programs that are persistent and non-volatile.
• Why is RAM considered volatile?

  Data in RAM is lost when the power is switched off.
• What cycle does the CPU perform to execute instructions?

  The CPU performs the fetch-decode-execute cycle.
• What are the learning objectives of the lesson on operating systems?

  • Describe the role of the operating system in a computer system
  • Identify tasks carried out by an operating system
  • Describe how the OS organizes files and allocates space on a hard drive
  • Construct an expression to calculate the number of blocks/sectors needed to store a file
  • Describe how file permissions control access to files
  • Select an appropriate level of file access for a user

  
• What are the two types of software that computers need to be useful?

  System software and application software.
• What is an example of application software?


  Web browsers and games.
• Which operating systems are mentioned in the study material?

  Linux, Microsoft Windows, and macOS.
• What is the main purpose of an operating system?

  To enable hardware to communicate effectively with software.
• What are the broad categories of tasks performed by an operating system?

  • File management
  • Process management
  • User management
  • Peripheral management
• How does the OS organize stored files?

  Using a hierarchy of directories and subdirectories.
• What is the purpose of access permissions in an operating system?


  To control who can perform actions on each file.
• What actions can be carried out on files according to the study material?

  Create, save, edit, open, delete, and rename.
• What are the different levels of access that can be granted to files?

  • Read: users can view the content but not alter it
  • Write: users can read and amend the contents
  • Execute: users can run the file if it is executable
  • Delete: users can remove the file

  
• What level of access should Alice have for the JavaScript code for the website?

  Read/write access.
• What level of access should Bob have for the register for his class?

  Read/write access.
• What does the term 'slack space' refer to in file management?

  Wasted space left when a file does not fill an entire sector.
• How does the OS allocate space on the hard disk?

  By breaking files into blocks that fit into sectors.
• What is the ceiling function used for in calculating required space?

  To round a number up to the next whole number.
• How would you express the number of blocks needed to store a file of size 2.8 KiB with a block size of 512 bytes?


  $\text{Number of blocks} =$$\lceil \frac{(2.8 \times 1024)}{512} \rceil$
• What is the maximum sector size used by the NTFS file system?

  64 kibibytes.
• What have you learned about the role of the operating system in a computer system?

  • The OS provides a platform for application software to run.
  • It enables communication between hardware and software.
  • It manages files, processes, memory, and peripherals.

  
• What are the responsibilities of the operating system?

  • File management
  • Process management
  • User management
  • Peripheral management