FIT1047 Chapter Notes - Chapter -: Operating System
31 May 2018
School
Department
Course
Professor
OS
Sunday, 15 April 2018
2:47 pm
An operating system provides a level of abstraction between hardware and software.
Hiding complicated, diverse, low level concepts behind a simple interface.
Computer:
Application programs never talks to the hardware directly. Instead it uses well defined interfaces in
the OS to access things like the network or the graphics hardware.
Operating system core tasks:
• Managing multiple processes running in parallel.
o A process is a program that is currently being executed.
• Managing the memory that processes use
• Provide access to file systems, the network and other I/O recourses.
Core functionality of an OS is provided by the operating system kernel, or kernel for short.
OS allows multiple programs to run in parallel.
Makes sure separate files are protected from unauthorised access. Ie. When 2 programs are running
at once, they caot read or write each other’s eory ad cause errors.
Abstraction
Goal of OS is to make computers easier to use, for both programmers and users.
For users, OS provides a consistent user interface, and it manages multiple applications running
simultaneously. (Also provides some level of protection from malicious or buggy code.)
For programmers the OS provides a programming interface that enables easy access to the
hardware and input/output devices. Also manages system resources such as memory, storage and
network.
The OS hides some of the complexity between consistent, well documented interfaces - for both
user and programmer.
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Document Summary
An operating system provides a level of abstraction between hardware and software. Hiding complicated, diverse, low level concepts behind a simple interface. Application programs never talks to the hardware directly. Instead it uses well defined interfaces in the os to access things like the network or the graphics hardware. Operating system core tasks: managing multiple processes running in parallel, a process is a program that is currently being executed, managing the memory that processes use, provide access to file systems, the network and other i/o recourses. Core functionality of an os is provided by the operating system kernel, or kernel for short. Os allows multiple programs to run in parallel. Makes sure separate files are protected from unauthorised access. When 2 programs are running at once, they ca(cid:374)(cid:374)ot read or write each other"s (cid:373)e(cid:373)ory a(cid:374)d cause errors. Goal of os is to make computers easier to use, for both programmers and users.
