Chapter 4 Flashcards
What is an operating system?
A type of system software that acts as the master controller for all activities that take place within a computer system
What does an operating system do?
Provides an environment for running software and controlling peripheral devices
Resource
Any component that is required to perform work
Ex. The processor is a computer’s main resource
How do operating systems manage processor resources?
Operating system must ensure that each process receives its share of microprocessor cycles
How do operating systems handle so many processes?
Multitasking, multithreading, and multiprocessing
Multitasking
Provides process and memory management services that allow two or more tasks, jobs, or programs to run simultaneously
Multithreading
Allows multiple parts, or threads, to run simultaneously within a single program
Multiprocessing
Supports a division of labor among all the processing units
How does an operating system manage memory?
Works with and executes instructions stored in RAM
Memory leak
When an application requests memory but never releases it
How does the OS keep track of storage resources?
Acts as a filing clerk that stores and retrieves files from computer’s hard drive and storage devices. Also remembers names, locations, and keeps track of empty spaces
Why does the operating system get involved with peripheral devices?
Communicates with device driver software so that data can travel smoothly between the computer and peripheral resources
Buffers
Collect and hold data while the computer is busy with other tasks
Single-user operating system
Deals with one set of input devices–those that can be controlled by one user at a time
Multiuser operating system
Allows a single, centralized computer to deal with simultaneous input, output, and processing requests from many users
Server operating system
Provides tools for managing distributed networks, e-mail servers, and Web hosting sites
Desktop operating system
Designed for a desktop or laptop personal computer
Mobile operating system
Designed for devices such as smartphones and tablet computers
Where is the operating system stored?
Usually stored on a hard disk because it is so large, but the operating system kernel is loading into RAM during the boot process
Kernel
Provides essential operating system services, such as memory management and file access
What is the boot process?
The sequence of events that occurs between the time that you turn on a computer and the time that is is ready for you to issue commands
Bootstrap program
Built into special ROM circuitry housed in the computer’s system unit
Name the six major events that happen during the boot process
- Power up
- Start boot program
- Power-on self test
- Identify peripheral devices
- Load operating system
- Check configuration and customization
Why doesn’t a computer leave operating system in memory
RAM is volatile, ROM is not large enough