CHAPTER 1: Introduction to Operating System - Coggle Diagram
CHAPTER 1: Introduction to Operating System
Act as an interface between the user and the hardware.
Start computer operation automatically when the computer is switched
Control the execution of programs.
Control input and output devices.
Manage processor time.
Permit file operations such as file creation, deletion, editing, renaming
and recovering lost data, etc.
Provide security for computer resources by way of user accounts,
Accounting resource usage who uses which resource, how much and when
OPERATING SYSTEM COMPONENT
Represents the operating system’s basic functions such as management of memory, processes, files, main inputs/outputs and communication functionalities. This components run all the time a computer is turned on
Allowing communication with the operating system via a control language, letting the user control the peripherals without knowing the characteristics of the hardware used, management of physical addresses
Allowing files to be recorded in a tree structure
OPERATING SYSTEM STRUCTURE
Kernel are all placed
components that perform similar functions are grouped together
OS divided into several processes, each implements a single set of services
Networked and distributed
resources in other independent computers on a network are accessible
PRODUCT OF OS
Closed source software is software that holds the source code safe and encrypted. Meaning, the user can't copy, modify, or delete parts of the code without some type of consequence
Open-source software is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software to anyone and for any purpose
OPERATING SYSTEM IN DIFFERENT PLATFORMS
SINGLE PROCESSOR SYSTEM
there is ONE main CPU capable of executing a general purpose instruction set, including instructions from user processes.
MULTI PROCESSOR SYSTEM
Multiprocessor system is a kind of processing system where two or more processors work together to process more than one program at one time. It helps the system to complete work in shorter period of time
Cluster systems like as parallel systems because both systems use multiple CPUs. But, main difference is that clustered systems are made by two or more individual systems but they are connected with each other.
Relationship between System Calls and Application Programming Interface (API)
User programs must ask the OS to access system resources directly
OS provides a set of functions that can be called by user programs to request for OS services. These functions are called “system calls”
System calls run in kernel mode.
APPLICATION PROGRAMMING INTERFACE (API)
User programs that follow the API’s definition are portable.
Using an API allows upgrading system software without changing user programs
An API clearly defines how to call functions and what the results are.
Graphical User Interface (GUI)
A type of user interface item that allows people to interact with programs in more ways than typing such as computers
CLI are often used by programmers and system administrators, in engineering and scientific environments, and by technically advanced personal computer users
Voice Actuated Interfaces
It makes human interaction with computers possible through a voice/speech platform in order to initiate an automated service or process
Web Form Interfaces
Web Form interfaces are onscreen forms displaying fields containing data items or parameters that need to be communicated to the user
Operating System Goals
Execute user programs and make solving user problems easier.
Make the computer system convenient to use.
Controls execution of programs to prevent errors and improper use of the computer
Manages all resources
Decides between conflicting requests for efficient and fair resource use
OS is a middle man between hardware and users, it works as
controls all program
then instruct hardware what to do
MAJOR FEATURES OF OS
In an operating system, multitasking means processing multiple task or programs at the same time without affecting the other task or program. For example, sending emails while listening to music
Multiprogramming is when two or more program are open at the same time and are sharing the processor. For example, when Google and Word is simultaneously running
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking
The buffer provides a waiting station where data can rest while the slower device catches up
Spooling refers to a process of transferring data by placing it in a temporary working area where another program may access it for processing at a later point in time
caching refers to copying information into faster storage system; main memory can be viewed as a last cache for secondary storage