hello im wondering if its possible to create an OS (operating system ) from a C++ level in DOS ? frankly, i am not a dos-expert, i do not even know dos commands; however, i do know that Windows 9x is a OS (right?), and was installed. problems i am having are creating multithreading abilites, and refrencing and allocating large amounts of memory, is it necessary to chunk these blocks or can i work with them whole? also, if u are familiar with the int86 or intx functions, i know that you send them a memory location, such as 0x33, and a number of parameters; this leads me to assume that there is a standard format for how the interupts are sorted in memory; is this true? on-line refrences would be great, thanks.

I dont see win9x as an OS for the simple fact that it required DOS to be installed. If you deleted DOS, windows couldnt run. DOS was the OS used by win9x, win9x was just a massive shell ontop of dos.

WinMe tries to hide dos, but its still there, still required to run.

I wouldnt say its possible to call something an OS when it requires a different OS to run, therefore I have to say no, you cant create an OS that runs on dos.

Win2K doesn''t use dos. ( I know u never said it did ).

Win2K doesn''t use dos. ( I know u never said it did ).

Win2K is based on NT, which doesn''t use DOS at all. In fact, the GUI is embedded in the kernel, so console functions are basically emulated. WinMe is based on 9x, which is totally different, and based on DOS.

As for creating an OS, first learn assembly VERY VERY well, then go here The Operating Systems collection.

-----------------------------

A wise man once said "A person with half a clue is more dangerous than a person with or without one."

The Micro$haft BSOD T-Shirt

Writing my own OS is one of my little ambitions. Something to get round to, like implementing a TCP/IP stack on my Atari 65XE. But I am nowhere near ready to write even a basic OS and by the sounds of it, neither are you. I don''t want to appear to be nagging or to be condemning, but building something capable of putting complex stuff on top of, really is a *massive* undertaking.

If you''re serious, though, I was recommended Andrew Tannenbaum''s books, by some guys from Scandinavia who are writing an OS. Something to do with a storm (the name, either of the whole package or the kernel). I forget. Wine does that to you! :-)

Hope I don''t sound too patronising,

Walking Beard

Just for fun, I''ll argue that Win9x is an OS...

It''s Windows, not DOS, that handles things like IO, scheduling, memory management, and IPC. Windows interfaces with the hardware, not DOS (except for the occasional 16 bit VXD, of course). Last time I checked, these were *relatively* important characteristics of an OS. Yes, DOS may be there, but does it actually _do_ anything? Not really. And, of course, the "unofficial" reason that Windows is an OS is that it''s all the end user ever sees and interacts with.

As for not being an OS if it runs overtop of another "OS" ... ever used VM/CMS?

~~~~~~~~~~
Martee
http://www.csc.uvic.ca/~mdill

The novell server runs on top of DOS... don''t know if thats classified as an os though...

Snale
+--My humble and superior homepage

Martee, Ive used VMWare before, if that counts :D
Though remember that the OS''s that VMWare boots dont require it to run, and can infact be installed to a partition and booted normally.

Win9x is a shell over DOS that takes over handling some of the tasks that DOS would otherwise handle. That doesnt make it an OS though, as it requires another OS to run.

Thats just my oppinion though, disagree with it all you like, just dont flame

Netware is a NOS, since at least v3.0 your could unload DOS after Netware loaded.

Even NT still uses the same interruapt calls to do disk access & etc.. as MS-DOS does/did. I'd say Win95+ is its own OS - the reason DOS is loaded is for backwards compatibility.


I wouldn't recommend a mutli-tasking, nm a multi-threading OS for your first attempt.


Magmai Kai Holmlor
- The disgruntled & disillusioned


Edited by - Magmai Kai Holmlor on May 18, 2001 9:59:16 PM