4.1 Types of Software and interrupts

• system software is the software that runs on the computer and controls the hardware.
• Application software is software that is designed to perform a specific task.
• Operating system is a program designed to run other programs on the computer and it manages both software and hardware resources.
• Utility programs are designed to perfom a specific task, such as file management, system maintenance, and system security.
• an example of a utility software would be a firewall that monitors network traffic
• freeware software doesn't allow users to access the source code.
• free software is where users can access the sources.
• free software allows the user to tailor the code to their needs
• free software is also known as open source
• freeware software is covered by copyright so the users must get the owners permission to access or alter the code.
• operating systems manages files and file permissions.
• operating system's file managers organise and control files
• An interrupts is a signal from the hardware or software to the CPU that stops the processor temporarily from completing the request immediatly. this is used to prevent errors such as crashes.
• users interact with the operating system using the interface. it converts user inputs to a form that the computer can understand. (vice versa)
• the operating system manges peripherals and drivers. making suer they're compatable.
• the operating system manges memory, processing, allocating and deallocating memory from RAM to virtual memory.
• the operating system mangeges multitasking using time slicing which splits different tasks into small segments.
• application programs and hardware communicate within the operating system called an API (application program interface)
• applications and hardware must communicate through the operating system

  
• firmware is the software that controls the hardware of a computer.
• interrupts must ensure that the CPU can stop executing its current program.
• interrupts need to be added to an area called the interrupt service routine.
• hardware interrupts are interrupts that are caused by hardware failure
• software interrupts are interrupts that occur when an application stops or a request from the OS is received e.g. ctrl alt del
• multitasking is created by applications interrupting each other to process different programs simultaneously.
• the interrupt handler handles the interrupts signals from the sender, it then prioritises the interruptions, creating a queue to be handled.