Operating Systems and Systems Software

Flashcards covering key concepts related to operating systems and their functionalities.

Operating System

A collection of programs providing an interface between the user and the computer, managing computer memory and resources.

Memory Management

The function of an operating system that ensures fair sharing of the main memory between multiple programs through techniques like paging, segmentation, and virtual memory.

Paging

A memory management scheme that eliminates the need for contiguous allocation of physical memory and ensures that the main memory is shared efficiently by splitting it into equal-sized sections called pages.

Segmentation

Splitting memory into logically sized divisions called segments, which represent the structure and flow of a program.

Virtual Memory

A memory management capability that uses hard drive space to simulate additional RAM when the main memory is insufficient.

Interrupts

Signals generated by hardware or software to inform the processor that it needs attention, allowing the operating system to manage processing efficiently.

Interrupt Service Routine (ISR)

A specific block of code executed by the processor to handle an interrupt when it occurs.

Scheduling Algorithms

Methods employed by operating systems to allocate processing time among various jobs that need execution.

Round Robin

A scheduling algorithm that assigns equal time slices to each job in a queue, cycling through until completion.

First Come First Served (FCFS)

A straightforward scheduling algorithm where jobs are processed in the order they arrive, without prioritizing based on urgency.

Multi-level Feedback Queues

A scheduling approach that uses multiple ready queues, each prioritized differently, to determine which job to execute next.

Embedded Operating System

An operating system designed to perform a limited number of specific tasks on embedded devices.

Real Time Operating System (RTOS)

An OS designed to execute tasks within a defined time constraint, crucial for time-sensitive applications.

Basic Input Output System (BIOS)

The initial program that runs when a computer is turned on, responsible for hardware checks and loading the operating system.

Device Drivers

Small programs that allow the operating system to communicate with hardware components.

Virtual Machine

A software-based simulation of a computer that allows running different operating systems and software.

Intermediate Code

Code that is neither machine code nor high-level code, used in virtual machines to enable execution across various architectures.