DOS is dead?

Well, sometimes I feel the need to play around with it.

So you call me a necrophiliac, huh!??!!! ;-)

Umm, I thought video mode switchs were made by the BIOS, not DOS. So you should be ok if you use the BIOS to switch to mode 13h, unfortunely I don't have my assembly book with me at the moment to confirm what the answer is.
But I think it goes some like this,
mov al,13h
int 10h

you'll have to wait until I get home before i can confirmed this.

-BM-

Edited by - Black Marq on November 22, 2001 4:54:32 PM

BIOS Functions(pre VGA and VGA)
INT 10h
Function 00h
Set Video Mode
Selects and initializes the video mode and clears the screen.

Input
AH = 00h
AL = Video Mode

---|Text-|Pixel|Graphic|Colours|Disp|Screen-|VGA|
---|Resol|-Box-|-Resol-|-------|Page|Address|YES|
00h|40x25|-8x8-|-none--|-B&W---|-8--|-B800--|YES|
01h|40x25|-8x8-|-none--|-16----|-8--|-B800--|YES|
02h|80x25|-9x16|-none--|-B&W---|-4--|-B800--|YES|
03h|80x25|-9x16|-none--|-16----|-4--|-B800--|YES|
---|80x25|-8x8-|-none--|-16----|-8--|-B800--|YES|
04h|40x25|-8x8-|320x200|-4-----|-1--|-B800--|YES|
05h|40x25|-8x8-|320x200|-4gray-|-1--|-B800--|YES|
06h|80x25|-8x8-|640x200|-B&W---|-1--|-B800--|YES|
07h|80x25|-9x14|-none--|-mono--|-1--|-B000--|YES|
---|80x25|-----|-none--|-------|-8--|-B000--|YES|
08h|20x25|-8x8-|160x200|-16----|----|-B800--|-NO|
09h|40x25|-8x8-|320x200|-16----|----|-B800--|-NO|
0ah|80x25|-8x8-|640x200|-4-----|----|-B800--|-NO|
0bh|reserved---|-------|-------|----|-------|YES|
0ch|reserved---|-------|-------|----|-------|YES|
0dh|40x25|-8x8-|320x200|-16----|-8--|-A000--|YES|
0eh|80x25|-8x8-|640x200|-16----|-4--|-A000--|YES|
0fh|80x25|-8x14|640x350|-mono--|-2--|-A000--|YES|
10h|80x25|-8x14|640x350|-4-----|-2--|-A000--|-NO|
---|80x25|-8x14|640x350|-16----|-2--|-A000--|YES|
11h|80x30|-8x16|640x480|-2-----|----|-A000--|YES|
12h|80x30|-8x16|640x480|-16----|----|-A000--|YES|
13h|40x30|-8x8-|640x480|-256---|----|-A000--|YES|

Enter into Standard VGA graphics mode 13h, 256 colours 320x200 pixels via BIOS.
xor ax,ax
mov al,13h
int 10h

Return to typical DOS TEXT mode 3 via BIOS(not DOS).
mov ax,3 ; Text Mode
int 10h

Should work be ok in Windows 2000 pro


-BM-

It's been I awhile since I played around with the BIOS, so things could have changed. The BIOS I know was written in 16bit code, calling with int10 from 32bit would make the cpu interpret the 16bit code as 32bit. That would get around to causing a crash eventually . Also there would be a problem with addressing and privilege levels.

The command.com on my computer runs in virtual 86 mode, which is like a full 16bit machine running inside my 32bit machine. Since all 386+ computers can do this I can't see why it wouldn't work in NT or 2000. In Windows a call to int10 calls the same way, but goes through a thunk layer to get to the 32bit device driver code. It's possible to get into v86 mode without using command.com or the thunk, and then you could call the BIOS directly.

If I am wrong about any of this, don't hesitate to mention it.

By the way the BIOS is not the same as DOS, every computer needs a BIOS to get up and running, long live the BIOS.

Anybody here know anything about EFI?

Edited by - burp on November 22, 2001 7:50:09 PM