A-level Computing 2009/CIE/Operating Systems
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Basic process flow:
__________________________________________________________________________________________________________ | | Yes | Yes | Yes V | | |
Start - Fetch - Decode - Execute - Check for interrupt - No - Check for more instructions - No - Return to previous instruction? - No - End
Operating system is made out of 4 components:
User interface - provides an interface for the user to communicate with the hardware
Kernel - translates the inputs from the U.I. in Machine Code for the hardware ( device drivers and utilities ) to understand
Device drivers - The set of instructions that the hardware can understand ( a user manual of the device for the kernel , basically )
Utilities - Power management, Managing Fragmentation, System Security etc.
The Scheduler is a part of the OS that manages how much time each process spends using the processor.