You can get the source code to Cosmos itself from the project's page at Codeplex, in the related links section.
Cosmos is designed to allow people to develop their own operating systems. Those who do so may, or may not, opt to make their source code public. You'd need to contact them directly to see if the source is available.
there are many type of open source operating system like Linux which provide their source code so you may edit it according to your need.but window is not give their source code.
Linux
If I understand your question....vague as it is....yes, the Unix OS source code is free and open source.
An OS where the source code isn't released to the public. Windows and Mac are 2 examples.
Open Source, whether it applies to an Operating System or a utility program means you have the source code and can modify it. Depending on the license used there may be some restrictions on your modifications so it is best to look at the license that comes with the Open Source software.
It's source code is not publicly distributed or documented.
There's no need to break the Android code (Android is an Open Source Operating System) as the source code of Android is already available over their developer section.
an assembler is aroutine program that translates assemly language source code to a machine language object code
Students understand the source code for the operating system and how Linux works without complications.
Students understand the source code for the operating system and how Linux works without complications.
That really depends what operating system you are talking about. You may want to clarify what operating system you are interested in. The source code of many commercial operating systems, such as Windows, is not freely available, so the answer is simply "you can't". However, the source code of other operating systems, such as the different Linux distributions, is available for free, and may even be modified legally. Please note that any operating system used in "real life situations" is a huge project; finding your way around the source code may be a daunting project. According to the Wikipedia, "As of 2013, the Linux 3.10 release had 15,803,499 lines of code." At 60 lines per page, that would be a quarter of a million pages, or about a thousand volumes, if it were to be printed.
windows 2000