4098800
Flashcards by Sophye Reynolds , updated more than 1 year ago
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Created by Sophye Reynolds
over 5 years ago
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Description
| Question | Answer |
| OPERATING SYSTEM FUNCTIONS In any computer, the operating system: controls the backing store and peripherals such as scanners and printers deals with the transfer of programs in and out of memory organises the use of memory between programs organises processing time between programs and users maintains security and access rights of users deals with errors and user instructions allows the user to save files to a backing store provides the interface between the user and the computer - for example, Windows Vista and Apple OSX | OPERATING SYSTEM: An operating system is a system program that controls and organises the general operation of the computer. |
| BOOTING THE COMPUTER: Computers powered by the central processing unit can only execute code found in the systems memory. Modern operating systems and application program code and data are stored on nonvolatile memories or mass storage devices. When a computer is first powered on, it must initially rely only on the code and data stored in nonvolatile portions of the systems memory. At boot time, the operating system is not really loaded and the computer’s hardware cannot peform many complex systems action. The program that starts the “chain reaction” which ends with the entire operating system being loaded is known as the boot loader (or bootstrap loader). The term creatively came from early designiners imagining that before a computer “runs” it must have it’s “boots strapped”. The boot loader’s only job is to load other software for the operating system to start. Often, multiple-stage boot loaders are used, in which several small programs of increasing complexity sequentially summon one after the other, until the last of them loads the operating system. | BOOTING THE COMPUTER: Booting is a start-up sequence that starts the operating system of a computer when it is turned on. A boot sequence is the initial set of operations that the computer performs when it is switched on. Every computer has a boot sequence. |
| RESOURCE SYSTEMS: Being the most fundamental of all system programs, Operating Systems are trusted with the job of controlling and sorting through the hardware, and this includes all the main components of the computer. To ensure that there is little confusion, the OS programs managing the key resources are giving relatively simple names depending on the resource they manage: Key Resource OS Program Processors Processor Scheduling Storage Memory management I/O devices I/O management Data File management | HANDLES SYSTEM RESOURCES: A resource, or system resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource. |
| THIS IS A RESOURCE SYSTEM. |
