Definition of an operating system

[spaghetti3451]

I tend to think of an operating system as an interface between the hardware and the application software. But, my lecturer says that that is a very misleading conception of an operating system.

Why do you think he would say that?

 

[Medicol]

http://en.wikipedia.org/wiki/Operating_system

 

[spaghetti3451]

I did look into Wikipedia. It mentions that it is a resource manager.

I just don't see how it cannot be a middleman between application software and hardware.

 

[mathman]

I did look into Wikipedia. It mentions that it is a resource manager.

I just don't see how it cannot be a middleman between application software and hardware.

It is, but it functions as a middleman between the hardware and everything else, not just application software.

 

[Medicol]

In that wiki link, there is an image to the right of the screen that states it all. You look at that image and use your own words to describe what an OS is.
Your lecturer is correct. OS functions not only as an "interface" but a manager of both hardware and software as well (e.g as an "interface", the OS provides an abstract api layer for your software program to interact with the hardware; and as a manager, it makes use of the hardware components to house your *compatible* software and reject it if any misplaced call to it is performed).

 

[FactChecker]

I think that you are not concentrating enough on how a user controls processes running on the computer and too much on the hardware.

Concentrate more on user control of processes and computer control of users: What jobs get priority? How does the user define the input and output files for a program to connect to? How does the user tell the computer what to run, when to run it, etc.? What tools are available to the user to edit files, control processes, etc.? Which users get priority? How is one user's information kept secure from other users? Which users are allowed to do privileged operations? Those are all OS issues.

Worry less about hardware interface: Most OSs run on a variety of hardware but are still considered the same OS. There is a lower level (board support) that interfaces the OS to the hardware that is not really part of the OS. Each computer manufacturer supplies a set of device drivers to get his hardware to work with that OS. It interfaces with the OS in a manor defined by the OS developers.

 

[SixNein]

I tend to think of an operating system as an interface between the hardware and the application software. But, my lecturer says that that is a very misleading conception of an operating system.

Why do you think he would say that?

Generally... an operating system consists of...

Process management and scheduling. For example, the OS usually has to manage the PCB, interrupts, etc.
Memory management - things like virtual pages and tables along with physical memory.
UI and other little system libraries, but a lot of these don't have to be included even though we generally think of them as part of the OS.

An interface between hardware and software that isn't an operating system would be something like TCP/IP. The operating system might handle the interrupts associated with this task; however, the magic is probably going to get done in a device driver.

 

[harborsparrow]

http://en.citizendium.org/wiki/Operating_system seems to me to be a better overview than Wikipedia has.