Video mode and text output

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joke
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Joined: Sat Jul 22, 2006 6:20 am

Video mode and text output

Post by joke »

Hi all,
i was wondering if it is possible in my real mode os to change the default black background color to white and the letters to black. But according to ralf brown's int list, in text mode only the border color is changeable. So i decided to change my video mode and go to graphics

xor ax,ax
mov ax,04h
int 10h

then i change the background color
xor ax,ax
mov ah,0Bh
mov bl,0Fh ;White
int 10h

and i've changed all my output functions
mov ah,0Eh
mov bl,00h ;black
int 10h

However what i get is a screen filled with an outstanding white and no black letters. How can i print black letters in graphics mode?

Thank you all!
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JAAman
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Joined: Wed Oct 27, 2004 11:00 pm
Location: WA

Post by JAAman »

i was wondering if it is possible in my real mode os to change the default black background color to white and the letters to black. But according to ralf brown's int list, in text mode only the border color is changeable. So i decided to change my video mode and go to graphics
using BIOS interupts, im not sure... but if you work directly with the screen (not hard to do), this is quite easy to do (and im quite surprised that the bios calls dont do it)

when writing the attribute byte, simply use the low nybble for the foreground, and the high nybble for the background
However what i get is a screen filled with an outstanding white and no black letters. How can i print black letters in graphics mode?
some video cards dont implement text->graphics translation (required for using int10/0E in graphics mode), however i cannot say if this is your problem
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