OSDev.org

I want to learn how to write OS about 16 bits,who
could recommend book or document,it can implement simple
functions,and the book need include detail explanation
and source codes,who could help me?

http://books.google.co.uk/books?id=_dhQ ... r_versions

A classic. I think you need the first or second editions for 16-bit code.

XINU

Get the IBM PC version of the book. http://www.amazon.com/Operating-System- ... words=xinu
Make sure you get the right version, there's a few different versions out there: Mac, Linksys router, LSI-11.

Get the code here: ftp://ftp.cs.purdue.edu/pub/Xinu/XINU-PC-BOOK-CODE.tar

I also wouldn't recommend any book (except perhaps something on assembly basics, logic, or even an English grammar book for various other reasons) until I manage to find out what keeps you stuck with the most simple problems and monkey-see-monkey-do behaviour.

What you need is a tutor, professional education, or more effectively, simply a different hobby.

---

For all the other readers: 16-bit is outdated and not worth your money.

Combuster wrote:I also wouldn't recommend any book (except perhaps something on assembly basics, logic, or even an English grammar book for various other reasons) until I manage to find out what keeps you stuck with the most simple problems and monkey-see-monkey-do behaviour.

What you need is a tutor, professional education, or more effectively, simply a different hobby.

---

For all the other readers: 16-bit is outdated and not worth your money.

I want to learn the OS,so I want to start learning from 16-bit,maybe I need basical tutorial

leetow2003 wrote:I want to learn the OS,so I want to start learning from 16-bit,maybe I need basical tutorial

May I point out that that opinion is the worst fallicy of OSDev. 16-bit code is not simple, nor is it a precursor to moving to 32-bit code. Writing code in real mode requires a completely different mindset to writing code in protected mode, and hence is not a good starting point.

Do yourself a favor, and start with 32-bit code (and once you have that down pat, MAYBE try 16-bit if you need to)

I want to learn the OS

I got confused when I read this.
Do you want to learn about an existing operating system like Windows or Linux or Want to learn
about Operating Systems Development?
Both are similar in certain ways, I have some good books about Linux,
And as for 16 bit code try reading some books about DOS Programming and x86 Assembly, And don't
forget RBIL (Ralf Brown's Interrupt List) great place for BIOS Interrupts.

I need a basical tutorial

What's up with the wiki? Is the wiki not enough for a basic tutorial. I guess there
are 4 of them. I dont know whether it could be helpful but Try to get a copy of 8086 Manuals.

This might be the worst advice in the world, but here's my opinion. I don't know how good your programming skills are, but with that being said I think the best way to really understand a language is to know what everything does. I know one way to do this with 16bit Assembly is to right a 8086 Emulator because then you learn every opcode, how the CPU works, and everything. I learned a lot when I began writing mine, there was a lot of head banging against the wall with miss information and errors in documents that I was reading but in the end it was really neat and will be beneficial later on. Or do what I did and jump to 32bit code in Assembly and just mess around till you understand everything.


Yours Truly, Matt

leetow2003 wrote:I want to learn the OS,so I want to start learning from 16-bit,maybe I need basical tutorial

Here's what your question sounds like to us: "I need a tutorial on driving cars from the '60s." Cars are still cars---you just need to get adjusted to the one you're driving. And, of course, be prepared to miss out on the newer developments, like automatic transmission, airbags, CD players, self-driving (okay, this is not yet commonplace but, given the economical benefits, it probably will be in 10 years' time), etc.

Analogies aside, you want to learn OS theory (and other theories that are related to your particular goal) and the details of the hardware you're going to implement your OS on (in this case, I suspect you mean PC's, although there are plenty of architectures which are ambiguously called "16-bit," which is mostly a marketing term rather than a technical one). Don't conflate the two even if you plan on using them together. If you were to write a book in a foreign language unknown to you, you'd develop the plot separately from learning the language, correct?

Combuster wrote:For all the other readers: 16-bit is outdated and not worth your money.

I think it is perfectly legitimate to develop a hobby OS in real mode. After all every hobby OS is a waste of money, and time, and effort. The only reward is satisfaction, which is not dependent on processor mode at all.

Hobbes wrote:

Combuster wrote:For all the other readers: 16-bit is outdated and not worth your money.

I think it is perfectly legitimate to develop a hobby OS in real mode. After all every hobby OS is a waste of money, and time, and effort. The only reward is satisfaction, which is not dependent on processor mode at all.

It depends on what you want to learn. If the OP wants to get a better insight into the way modern operating systems handle memory and processes, then he should steer well clear of 16-bit real mode.

OP: if you really want to learn about real mode OSes, you might find the code in MikeOS (http://mikeos.berlios.de) useful. It's pretty well documented and I've written a lot about its working in the Handbooks. Just be aware that real mode OSes are something of a cul-de-sac -- they can be fun to play around with, as you can get results very quickly, but a lot of the stuff you learn won't be much use if you decide to make a "proper" protected mode OS later on.

Mike

Hobbes wrote:I think it is perfectly legitimate to develop a hobby OS in real mode. After all every hobby OS is a waste of money

You made me curious, how much actual money did you spend solely in the name of your OS? Was it worth it?

Your advice is very important to me.Thank you very much.

if your objective at the end is to develop modern 32 bit protected mode OS, there is really little need to learn 16 bit real mode, as you can already find plethora of tools that are already very mature who can do all the 16 bit real mode part , like boot loaders, and in modern OS, 16 bit real mode is really only used for the boot loader in the very first stages

it can be useful if you want to do some kind of dos emulator, or you want to have to deal with code wrote in 16 bit mode, or the bios, and modern intel still can operate in a mode 100% compatible with 16 bit real mode, so it's still in the intel, and modern intel can still technically run code made for 16 bit real mode, but it's still a very different approach to everything compared to how modern os are made, using paged virtual memory, memory protection, and multi tasking, and learning real mode will give you very little benefits to develop os in the modern way