OCR H446/01 Computer systems · 1.2.1

Systems Software

Revision notes for OCR A Level Computer Science (H446) 1.2.1 Systems Software.

Revision notes

• a.The need for, function and purpose of operating systems
• b.Memory management: paging, segmentation and virtual memory
• c.Interrupts, Interrupt Service Routines (ISR) and their role in the FDE cycle
• d.Scheduling: round robin, FCFS, multi-level feedback queues, SJF and SRT
• e.Distributed, embedded, multi-tasking, multi-user and real time operating systems
• f.BIOS
• g.Device drivers
• h.Virtual machines: executing intermediate code and running one OS within another