Unit - 1 Notes On Operating System(OSY) Introduction Of Operating System
Operating System acts as an intermediary between the user of a computer and the computer hardware. The purpose of an operating system is to provide an environment in which a user can execute programs in a convenient and efficient manner. Mainframe operating systems are designed primarily to optimize utilization of hardware. Personal computer (PC) operating systems support complex games, business applications and everything in between. Mobile computer operating systems provides an environment in which a user can easily interface with the computer to execute programs
Unit - 2 Notes On Operating System(OSY) Structure Of Operating System
On completion of this lesson you will know : what interrupt is the causes of occurring interrupt instruction cycle with interrupt I/O structure.
Unit - 3 Notes On Operating System(OSY) Process Management
UNIT - III STORAGE MANAGEMENT Main Memory Background Memory is central to the operation of a modern computer system. The part of the OS that manages the memory hierarchy is called the memory manager. to keep track of which parts of memory are in use and which parts are not in use, to allocate memory to processes when they need it and deallocate it when they are done, to manage swapping between main memory and disk when main memory is too small to hold all the processes. Memory consists of a large array of words or bytes, each with its own address. The CPU fetches instructions from memory according to the value of the program counter. These instructions may cause additional loading from and storing to specific memory addresses. The memory unit sees only a stream of memory addresses; it does not know how they are generated (by the instruction counter, indexing, indirection, literal addresses, and so on) or what they are for (instructions or data)
Unit - 4 Notes On Operating System(OSY) Scheduling
Central Process Unit (CPU) scheduling deals with having more processes/threads than processors to handles those tasks, meaning how the CPU determines which jobs it is going to handle in what order. A good understanding of how a CPU scheduling algorithm works is essential to understanding how an Operating System works; a good algorithm will optimally allocate resources, allowing an efficient execution of all running programs.
Unit - 5 Notes On Operating System(OSY) Partitioning
A file is a named collection of related information that is recorded on secondary storage. A file is the smallest allotment of logical secondary storage (i.e.) data cannot be written to secondary storage unless they are within a file. Files represent programs and data. Data files may be numeric, alphanumeric or binary. The information in a file is defined by its creator. Different types of information may be stored in a file such as source or executable programs, numeric or text data, photos, music, video and so on.
