# Understanding some operating system code



## SactoMike711 (Apr 24, 2019)

My goal is to understand the operating system code that controls the console, or the hard drive, or the various peripherals, or all of the above. I think the most practical way of understanding such code would be to study FreeDos. Does anyone know of any literature in print, or on the internet, that explains exactly how such code functions? 
Thanks


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## Macboatmaster (Jan 15, 2010)

I am not quite sure exactly what you refer to
FreeDos commonly means the DOS OS released under public licence
https://en.wikipedia.org/wiki/FreeDOS

That is not MS-DOS
https://en.wikipedia.org/wiki/MS-DOS

and in all Windows editions since ME - DOS is not actually used, it is more correctly called Windows Command shell - in other words the cmd prompt which used what may be called DOS based cmds
https://superuser.com/questions/319056/does-windows-still-rely-on-ms-dos

So when you say


SactoMike711 said:


> *My goal is to understand the operating system code that controls the console, or the hard drive, or the various peripherals,* or all of the above.


as I said the question is - in which environment do you refer to


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## SactoMike711 (Apr 24, 2019)

Well, I was referring to the FreeDos for which you provided a link. Since FreeDos has been open source since it was first written, I thought that there should be some literature written in the last 25 years that would explain, in exact detail, the code of FreeDos. Also FreeDos should be a simpler operating system to understand than an operating system like Linux. Therefor, I thought that FreeDos would be the most "practical" operating system to study.


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## Macboatmaster (Jan 15, 2010)

SactoMike711 said:


> Therefor, I thought that FreeDos would be the most "practical" operating system to study.


Is this some form of school/college course where you choose a study option.
If so the information I have provided would likely be the extent of our help
It should not be too hard to find the literature - and such task is IMHO an integral part of such course work

From our rules


> It is our policy not to assist members with homework-related questions. While the Internet is indeed a great resource for helping students with their assignments, we feel that an important part of the learning process involves putting in the effort required to do the research needed to find the solution. Providing students with the answers does nothing to help them actually understand the assignment or develop valuable problem-solving skills.


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## SactoMike711 (Apr 24, 2019)

No, I am an amateur robotics enthusiast. I am not involved in any course on the subject. Over the years I have looked for literature that explains operating systems. I have found literature, but none of it was any good--at least for me. For instance I purchased Understanding the Linux Kernel by Bovet and Cesati. The book was full of generalizations and of no value at all to me.


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## managed (May 24, 2003)

I would look at Linux, there is a lot of information at the level you want to operate at.

Dos is more or less dead now, it's not even included in Windows any more, the CMD window is just an emulation of it.

Do you just want to understand how things are done or do you want to write code yourself ?
Maybe learning a higher level programming language would be the way to go.


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## Macboatmaster (Jan 15, 2010)

Indeed I agree with my colleague *managed*


managed said:


> Dos is more or less dead now, it's not even included in Windows any more, the CMD window is just an emulation of it.


as I mentioned



Macboatmaster said:


> and in all Windows editions since ME - DOS is not actually used, it is more correctly called Windows Command shell - in other words the cmd prompt which used what may be called DOS based cmds


However now you have confirmed it is not for some study course I suggest you see this
http://www.freedos.org/press-kit/
and the sub links
I am reasonably certain if you emailed Mr Hall from the link on the site and explained briefly what you want to do or learn, he would provide you with the necessary details to publications or whatever

Here
http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/ebook/using-freedos-24/using-freedos-24.pdf
appears to be good for starters


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