If I use write, all the line goes up.

Il faut crire directement dans la mmoire vido :

Sur un cran couleur en mode texte, la mmoire vido commence l'adresse
$B800:0000

On y trouve, pour chaque caractre, le code ASCII suivi du code attribut (couleur).
Le dernier caractre se trouve (80*25 - 1) * 2 = 3998 octets plus loin,
c'est--dire l'adresse $B800:3998 et son attribut l'adresse suivante.

It's possible, but not using write.

You will have to write directly in video memory :

On a color screen in text mode, the video memory begins at address $B800:0000

You can find there, for each character, the ASCII code followed by its attribute
(color). The last character is located (80*25 - 1) * 2 = 3998 bytes forward,
id est at address $B800:3998 and its attribute at next address.

Hope this will help

procedure putchar(x,y:word;c:char); assembler;
asm
        mov     ax,0b800h
        mov     es,ax
        mov     ax,160
        mul     y
        mov     di,x
        shl     di,33   ; fast version of shl reg,1
        add     di,ax
        mov     al,c
        mov     es:[di],al
end;    

That will place a character on a color screen without moving it or changing
the WhereX or WhereY (ie, cursor position).

This problem is covered in

 80222 Jun 16 09:13 ftp://garbo.uwasa.fi/pc/ts/tsfaqp24.zip
 tsfaqp24.zip Common Turbo Pascal Questions and Timo's answers

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