problem with a text displaying code....

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windwakr

Joined: 30 Jun 2004
Posts: 827

windwakr 06 Aug 2004, 17:40

I found this code on the forum somewhere....the problem is that it adds a space after the string you use. how would that be fixed

Code:

ORG 100H

TX = 80

; Some color names to use instead of raw numbers
BLACK = 0
BLUE = 1
GREEN = 2
PURPLE = 3
RED = 4
CYAN = 5
BROWN = 6
WHITE = 7
GREY = 8
BRIGHTBLUE = 9
BRIGHTGREEN = 10
BRIGHTPURPLE = 11
BRIGHTRED = 12
BRIGHTCYAN = 13
BRIGHTBROWN = 14
BRIGHTWHITE = 15

virtual at 0
   write:
        .x        dw   ?
        .y        dw   ?
        .back   db   ?
        .fore    db   ?
        .str    dw  ?
end virtual

macro mov a, b {
   local c, d
     if b eqtype ''
      jmp d
      label c
      display b
      db b,0
      label d
        mov ax, c
        mov [write.str], ax
     else
      move a, b
    end if
}
move fix mov

macro write_string text, x, y, fg, bg {
   mov [write.x], x
   mov [write.y], y
   mov [write.back], bg
   mov [write.fore], fg
   mov [write.str], text
   call WriteStr
}

push cs
pop ds
push $b800      ; Set ES here, unless you need to alter it later on
pop es          ; It'll save a little time when you call WriteStr

mov ax,03h
int 10h

   mov [write.x], 10
   mov [write.y], 10
   mov [write.back], GREY
   mov [write.fore], BLUE
   mov [write.str], 'this is a test'
   call WriteStr
; Or this way:
;  write_str 'this is a test', 10, 10, GREY, BLUE

xor ax,ax
int 16h
int 20h

WriteStr:
        mov   ax, [write.y]       ; THIS ROUTINE WAS FIXED
        dec   ax            ; THE OFFSET ONSCREEN
        mov   cx, TX        ; WAS CALCULATED WRONG/
        mul   cx            ; NOW THIS IS OK !
        add   ax, [write.x]       ;
        shl   ax, 1         ; optimised
        mov   di, ax

        mov   ah, [write.back]
        mov   al, [write.fore]
        shl   ah, 4
        or    ah, al

        mov   si, [write.str]
      Continue:
        mov al, byte [si]
        stosw
        inc si
        cmp al, 0
        jnz Continue
ret

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06 Aug 2004, 17:40

crc

Joined: 21 Jun 2003
Posts: 637
Location: Penndel, PA [USA]

crc 06 Aug 2004, 18:08

Easy enough. Just change the end of the WriteStr routine to:

Code:

      Continue:
        mov al, byte [si]
        stosw
        inc si
        cmp byte [si], 0
        jnz Continue
ret

And all will be well Smile

06 Aug 2004, 18:08

windwakr

Joined: 30 Jun 2004
Posts: 827

windwakr 06 Aug 2004, 18:25

Thanks!

06 Aug 2004, 18:25

Matrix

Joined: 04 Sep 2004
Posts: 1166
Location: Overflow

Matrix 04 Sep 2004, 21:55

I give a sample code on how to write to screen by writing to memory mapped port @ $A000 segment

Code:

writestring80x25: ; DX = address of string bl=x bh=y cl=color , 0 terminated string !
push ds
push si
push es
push di
push $b800
pop es
mov si,dx
mov ax,80
mul bh
xor bh,bh
add ax,bx
shl ax,1
mov di,ax
mov ah,cl
again:
lodsb
or al,al
jz done
stosw
cmp al,0
jmp again
done:
pop di
pop es
pop si
pop ds
ret

moderated myself ---

Last edited by Matrix on 29 Oct 2005, 01:37; edited 3 times in total

04 Sep 2004, 21:55

Matrix

Joined: 04 Sep 2004
Posts: 1166
Location: Overflow

Matrix 05 Sep 2004, 01:21

windwakr wrote:

I found this code on the forum somewhere....the problem is that it adds a space after the string you use. how would that be fixed

Code:

ORG 100H

TX = 80

; Some color names to use instead of raw numbers
BLACK = 0
BLUE = 1
GREEN = 2
PURPLE = 3
RED = 4
CYAN = 5
BROWN = 6
WHITE = 7
GREY = 8
BRIGHTBLUE = 9
BRIGHTGREEN = 10
BRIGHTPURPLE = 11
BRIGHTRED = 12
BRIGHTCYAN = 13
BRIGHTBROWN = 14
BRIGHTWHITE = 15

virtual at 0
   write:
        .x        dw   ?
        .y        dw   ?
        .back   db   ?
        .fore    db   ?
        .str    dw  ?
end virtual

macro mov a, b {
   local c, d
     if b eqtype ''
      jmp d
      label c
      display b
      db b,0
      label d
        mov ax, c
        mov [write.str], ax
     else
      move a, b
    end if
}
move fix mov

macro write_string text, x, y, fg, bg {
   mov [write.x], x
   mov [write.y], y
   mov [write.back], bg
   mov [write.fore], fg
   mov [write.str], text
   call WriteStr
}

push cs
pop ds
push $b800      ; Set ES here, unless you need to alter it later on
pop es          ; It'll save a little time when you call WriteStr

mov ax,03h
int 10h

   mov [write.x], 10
   mov [write.y], 10
   mov [write.back], GREY
   mov [write.fore], BLUE
   mov [write.str], 'this is a test'
   call WriteStr
; Or this way:
;  write_str 'this is a test', 10, 10, GREY, BLUE

xor ax,ax
int 16h
int 20h

WriteStr:
        mov   ax, [write.y]       ; THIS ROUTINE WAS FIXED
        dec   ax            ; THE OFFSET ONSCREEN
        mov   cx, TX        ; WAS CALCULATED WRONG/
        mul   cx            ; NOW THIS IS OK !
        add   ax, [write.x]       ;
        shl   ax, 1         ; optimised
        mov   di, ax

        mov   ah, [write.back]
        mov   al, [write.fore]
        shl   ah, 4
        or    ah, al

        mov   si, [write.str]
      Continue:
        mov al, byte [si]
        stosw
        inc si
        cmp al, 0
        jnz Continue
ret

i think you have over complicated your code a bit,
you should see the problem first time looking at it, the first reason is because you wrote it Smile

moderated myself ---

Last edited by Matrix on 29 Oct 2005, 01:43; edited 1 time in total

05 Sep 2004, 01:21

Matrix

Joined: 04 Sep 2004
Posts: 1166
Location: Overflow

Matrix 09 Sep 2004, 17:21

you might also want to see this topic:

http://board.flatassembler.net/topic.php?t=2186

MATRIX

09 Sep 2004, 17:21

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