.model small
.data
str1 db "Force$"
.stack
.code
mov ax,@data
push ax
pop ds
mov al,ds:00h ;Get first byte of data segment
mov dl,al
mov ah,02h
int 21h
mov ah,4ch
int 21h
end
Hi !..
In this code i get 1 byte from data segment directly
and i tried to get 1 byte from stack segment with same way
I added this code but its failed
mov bl,dl
push bx
mov al,ss:00h
mov dl,al
mov ah,02h
int 21h
pop bx
Is it imposibble or my code is wrong ?
At least in this case, your assumption that str1 is at the beginning of the data segment is wrong.
.model small
.data
str1 db "Force$"
.stack
.code
start:
mov ax,@data
push ax
pop ds
I=0
REPEAT 20
mov dl,ds:I
mov ah,02h
int 21h
mov dl, 13
mov ah,02h
int 21h
mov dl, 10
mov ah,02h
int 21h
I=I+1
ENDM
mov bx, OFFSET str1
mov cx, SIZEOF str1
@@:
push cx
mov dl, [bx]
mov ah,02h
int 21h
inc bx
pop cx
dec cx
jnz @B
mov dl, 13
mov ah,02h
int 21h
mov dl, 10
mov ah,02h
int 21h
xor ah, ah
int 16h
mov ah,4ch
int 21h
end start
☻
═
!
2
Σ
═
▬
┤
L
═
!
F
o
r
c
e
$
K
V
Force$
Hi,
You are using the DOS Console Output function to show
the byte from the stack segment. That is used for character
output. The stack segment is usually zeroed out and the
character for '00'H is a blank at best. So you will not see
anything. Try a hexadecimal output routine. Or use the
other form of declaring a stack segment.
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; Set up the code definitions the operating system wants. Stack segment:
STCKSEG SEGMENT STACK
DB 48 DUP('STACK!!!') ; Stack area, and filler (384 Bytes)
STCKSEG ENDS
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Also useful sometimes when checking for stack usage problems.
You can make a listing to see if the data is laid out as you
expect as well.
HTH,
Steve N.
My poor side in x86 is segments
i dont have enough knowladge about them so I asked that kind of question
Steve how can i use hex ? can u post a simple code ?
the attachment on the following post has a copy of SymDeb and a little example of using it...
http://www.masm32.com/board/index.php?topic=18481.msg156179#msg156179
Hi,
Here is a thread were I posted some code to print AL as
hexadecimal. Or a larger value byte by byte. There is code
in the thread as well by Dave (dedndave).
http://www.masm32.com/board/index.php?topic=13415.msg106047#msg106047
Cheers,
Steve
Thanks all
hope those examples helps me
Quote from: Force on March 11, 2012, 02:41:26 PM
.model small
.data
str1 db "Force$"
.stack
.code
mov ax,@data
push ax
pop ds
mov al,ds:00h ;Get first byte of data segment
mov dl,al
mov ah,02h
int 21h
mov ah,4ch
int 21h
end
Hi !..
In this code i get 1 byte from data segment directly
and i tried to get 1 byte from stack segment with same way
I added this code but its failed
mov bl,dl
push bx
mov al,ss:00h
mov dl,al
mov ah,02h
int 21h
pop bx
Is it imposibble or my code is wrong ?
Hiya Force
Sorry to come to the party so late, but if you're still wandering, I have an explanation. You put BX on the stack, and pushed it on TOP . Then you read a byte from the BOTTOM of the stack. You just need to read and write from the same location of a given segment
and you'll be fine.
Here's an example.
DATA SEGMENT
DB 'FORCE',24H
DATA ENDS
STACK SEGMENT STACK 'STACK'
DB 64 DUP('IMASTACK') ;; it does help me to see if I wrote to ss or not, if 'F' prints, I did
STACK ENDS
CODE SEGMENT
ASSUME CS:CODE, DS:DAT, SS:STACK
MAIN PROC FAR
PUSH DS
SUB AX,AX
PUSH AX
MOV AX,DATA
MOV DS,AX
MOV BL, BYTE PTR DS:0 ;; fetch first byte from ds
MOV SS:0, BL ;; write it to first byte of ss for later
PUSH BX ;; push onto stack like you done
MOV BP,SP ;; fetch its index
MOV DL, BYTE PTR [BP] ;; copy and print
MOV AH,02
INT 21H
MOV DL, BYTE PTR SS:0 ;; now copy and print your first byte from stack
INT 21H
RET
MAIN ENDP
CODE ENDS
END MAIN
Quote from: Force on March 11, 2012, 02:41:26 PM
I added this code but its failed
mov bl,dl
push bx
mov al,ss:00h
mov dl,al
mov ah,02h
int 21h
pop bx
Is it imposibble or my code is wrong ?
first, this is invalid coding
mov al,ss:00hwhat you may have meant was
mov al,ss:[00h]but - SS:[0] does not point to the item that was just pushed
it points to what is tradionally called the "bottom" of the stack
it is unlikely and undesirable that you would ever place anything at that location with PUSH
push bp
push dx ;the contents of DL is what you are interested in
mov bp,sp ;in 16-bit, you cannot use SP to address stack data directly
mov dl,[bp] ;you should use BP (notice that DL will not change, here)
mov ah,2
int 21h
pop bx ;you wanted it in BX, i guess
pop bp
Sorry for late replying...
I was far from forum for 1 month .. I just noticed last posts
Thanks for helping Locche and Dave :U