Computer Science for Year 10 and 11 -Chapter 3.2 -Computer architecture and the fetch-execute cycle

Describe the purpose of an operating system (You will be required to understand the purpose and function of an operating system and why it is needed. you will not be required to understand how operating system work.)
Show understanding of the need for interrupts
Show understanding of the basic Von Neumann model for a computer system and the stored program concept (program instructions and data are stored in main memory and instructions are fetched and executed one after another)
Describe the stages of the fetch-execute cycle, including the use of registers and buses