Systems Software - A Level Computing

This is a revision document with the notes from lessons. All of the content included in this booklet is what you need to know about Unit 1.2.1 from OCR’s A Level Computer Science specification.

Perfect to use for revision, or as a handout.

Includes the following sub-topics:

• The need for, function and purpose of Operating Systems
• Memory management (Paging, segmentation & virtual memory)
• Interrupts (the role of interrupts and Interrupt Service Routines (ISR), role within the fetch decode execute cycle)
• Scheduling (round robin, first come first served, multi-level feedback queues, shortest job first, remaining time)
• Distributed, embedded, multi-tasking, multi-user, and real time operating systems
• BIOS
• Device Drivers