What is the difference betwen the ROM BIOS functions and the DOS functions?

Do the DOS functions have to be loaded from disk?
Posted on 2003-12-14 14:21:37 by Station
There is quite a big diffrence between ROM BIOS and DOS functions. DOS functions can only be used once dos is loaded. BIOS functions require BIOS to be loaded(happens when you turn on the computer). BIOS starts the POST(Power On Self Test). after this, the boot sector(i have only used a floppy so far but it should be pretty close) off the floppy gets loaded into memory at the address 0000:7C00h this is where you put your Boot Loader code to read your kernel into memory and set up the stack. During this time you have only BIOS functions and any other function you fit into that sector.

Now that you have gone through the very short Write your own OS 101, back to your question. I uploaded a reference that contains information on interrupts, and tells whether they are DOS or BIOS function, as well as many other helpful references. if you would like a copy of my brief OS(it is very small) pm me, and i will send it to you as well. If you have any further questions let me know. I have done enough research into this to explain the basics of it, but am not a pro by any means.:alright:
Posted on 2003-12-14 15:00:43 by jakor
Thanks for your reply. I'm quite interested to see your OS as this is something I'd like to create one day.

Something else I'm interested to know is whether the command prompt/console is part of DOS of the BIOS.
Posted on 2003-12-14 15:41:55 by Station
well, i will upload my OS...(NO LAUGHING!!!)
i was writting a text editor, and thought about some other stuff to add, but most of those functions arn't working... but i do have prompt manipulation...(o by the way i am not parseing out everything yet...if you hit ESC it will display the ASCII character for the ESC key character code ect...) i also messed with the arrow keys, but they arn't finished yet. so here it is...(by the way this will be my kernel of my OS you have to run it in DOS so i added a batch program to run it from windows just cause it runs in windows doesn't mean it uses windows... if you wanted to write the boot loaded(which i am not releasing for stability reasons) go ahead, just recompile with NASM and chage the org directive to whatever you need and have it restart the computer instead of exit to dos... other than that it is all BIOS interrupts)(yes i do have a bootable version too)
Posted on 2003-12-14 16:35:52 by jakor