A-Level Computer Science – Operating Systems Explained (Memory Management & Paging) (OCR / AQA) | S2:Ep 1

New Episode Every Monday In this Episode we focuses on the functions of an operating system, a critical piece of software that manages computer hardware and provides interfaces. Key areas discussed include memory management, detailing methods like paging, which divides memory into fixed-size chunks, and segmentation, which uses variable-length parts related to program structure. The concept of virtual memory is also explained, where a portion of the hard drive is used to extend available RAM, though frequent swapping can lead to performance issues known as disk thrashing. Furthermore, the document covers interrupt handling, outlining how the CPU responds to signals from hardware, software, or the internal clock using an interrupt service routine and a stack to manage priorities. Finally, processor scheduling is described, illustrating how the OS allocates CPU time to multiple applications to create the illusion of multi-tasking, and various scheduling algorithms are introduced, such as round robin, first come first served, shortest job first, shortest remaining time, and multi-level feedback queues.