6.2 Functions of an Operating System Flashcards
What are the four main roles an Operating System does?
Device Configuration
Files Management
Memory Management
Interface Platform
What does Device Configuration mean?
Controls Peripheral devices connected to the computer
What does File Management mean? [4]
Transfers files between main memory and secondary storage.
Manages file folders.
Allocates secondary storage space
File protection and recovery.
What does memory management entail?
Allocates the use of RAM to requesting processes.
What is the interface platform?
Allows the computer to run other applications.
How does the OS achieve its roles? [6]
It controls peripheral devices Manages Primary and Secondary Memory Controls Virtual Memory Provides an Interface Time Slicing Interrupt Handling
How does the OS control peripheral devices?
Through drivers, which allows translation programs to translate the input/output information from the peripherals.
How does the OS manage primary Memory?
The OS ensures each program runs in its allocated memory space.
What problems could occur if the programs are not allocated primary memory space?
corruption and security issues
What is the role of Virtual Memory for the OS?
Virtual Memory compensates for shortages in physical memory by temporarily transferring data from RAM to disk storage.
How does the OS manage secondary Memory?
The OS provides structure to secondary storage called folder-structure
What is the folder-structure?
it is a file system that allows the OS to store data in organised positions, and that they are secure.
What does the User interface allow?
User interface allows the user to interact with the system.
User sends input/output data through the interface which sent to the correct memory address to be processed.
What is time-slicing?
A time slice in a multi-user system is the set amount of processing time each user gets.
In a single-user system, a time slice is the set amount of processing time each program gets.
Why does an OS time-slice?
The slices are alternately processed to give the illusion of many tasks happening at once.
What is an interrupt?
a high quality task that needs the current code to stop to complete.
What is interrupt handling?
The interrupt handler in the OS causes the program to stop.
What techniques does the OS use to manage resources? [6]
Scheduling Polices Multi-tasking Paging Interrupt Polling
What is scheduling?
The process of assigning resources to complete the work.
What are policies?
The policies is the OS telling what is to be done, and how long you have to do it.
What are mechanisms?
The OS mechanism tells it how it is to be done.
Why are policies and mechanisms separated in the OS?
The separation of mechanism and policy allows flexibility for the system.
What is paging?
Paging is the process of moving RAM to disk storage.
Paging is carried out by the MMU (memory manager unit)
What does interrupt allow?
To help prioritise important instructions.
