Operating System Flashcards
Operating system
set of programs that control how the user interacts with hardware and software of a computer
9 Functions of an operating system
- Provides a user interface for applications
- Opens, closes and installs software
- Manages the hardware and peripherals
- Manages memory e.g. loading programs into RAM
- Manages processor time allocation
- Manages interrupts and error handling
- Manages file handling e.g. organising, saving and deleting
- Manages security e.g. logging on and passwords
- Manages user accounts
Device driver
software that allows peripheral devices to communicate with OS
translates signals to/from peripherals to something OS can understand
Spooling
simultaneous peripheral operations on-line
data is temporarily held in buffer waiting for an output device to access it
useful when peripherals access data at slower rates
OS multi-tasking
allows multiple tasks to run concurrently
shares processor time between programs
OS multi-programmung
several programs are running at once
Batch processing
programs or data are collected together in a batch and processed in one go
OS scheduling
determines the order in which programs should use the CPU and how much time is allocated to each one
interrupt
signal sent from a device or software to OS or CPU
causes processor to temporarily stop what it’s doing to service the interrupt
buffers
temporary memory area
store data being transferred between components
polling
OS regularly checks each peripheral device in turn to discover whether it needs the attention of the operating system
less efficient CPU use than interrupts, as CPU has to constantly poll devices
utility software
programs that perform specific tasks required for operation of computer system
disk defragmenter
moves parts of files around so all parts are stored together
free memory space is collected together
memory management
OS assigns blocks of memory to programs running in a computer
