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K.J. · **Posted:** Fri Feb 08, 2002 1:13 pm

I don't think that the full source would help much but I was looking at your code and saw:

;videoseg base 0xB8000 limit 4000
descriptor 48, 0FA0h, 08000h, 0Bh, 092h, 040h, 0

If your kernel is in real mode the videoseg base should be 0xB800 I think(anyone know for sure?). I suggest that maybe you should just use one of John Fine's bootsectors:

http://www.execpc.com/~geezer/johnfine/index.htm

K.J.

mansonbound · **Posted:** Sat Feb 09, 2002 3:29 am

hey you dont need a gdt for realmode.

mansonbound · **Posted:** Sun Feb 17, 2002 8:48 am

ok guys...heres what i found out:

i tried this:

Code:

char *message="H A L L O ";

int main()
{
        movedata(DATA_SEL, message, SCREEN_DATA_SEL, 0, 3000);
        while(1);
}

and saw:

HALLO in the 4th line of the screen. The start of the 4zh Line has the offset 0x1E0. Had alook with a hexeditor:
0x1E0: H A L L O . So instead of the adress of message the function is called with 0 instead of message.

Any comments?

K.J. · **Posted:** Sun Feb 17, 2002 10:19 am

Yeah, I don't get it.

K.J.

mansonbound · **Posted:** Fri Mar 01, 2002 11:12 am

ok...its going on:

i threw away all the c code :-(

and did something in asm.
so i reserved mem for a variable:

a: DW 0x721
;(gray '!')
and i move it to the 1st characer of the vidmem.
mov eax, 0xB8000-0x80000
mov dx, [a]
mov [eax], dx

It works, when the variable is declared at an offset below 0x200. (moved the position of a with TIMES .... nop and looked at it in a hexeditor)

Tim · **Posted:** Mon Mar 04, 2002 1:40 am

Is this code in a boot sector, or is it a file loaded by your boot sector code. Either way, it looks like you're only loading one sector.

mansonbound · **Posted:** Mon Mar 04, 2002 6:55 am

It is a file loaded by the bootsector code.
And no! not just 512b are loaded, cause the Code (Also higher than 0x200 WORKS)

mansonbound · **Posted:** Mon Mar 04, 2002 7:06 am

"ok...guess we can close the file on that one"

Hmm....i thought....everything above 0x200 is nil, but code over 0x200 works....so i had another look in the bootsectorcode, where the file is loaded and 512 is added to the adress after loading a sector:

mov bx, es
add bx, word [bps] ;<<-----------heres the error
mov es, bx

so i fixed it and now it works.
TY for all the trouble that i've done to you :-)

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