assembly programlama dili nasıl öğrene bilirim (2. sayfa)

section .data 
   
      ; Messages 
   
      msg1        db      10,'-Calculator-',10,0 
      lmsg1       equ     $ - msg1 
   
      msg2        db      10,'Number 1: ',0 
      lmsg2       equ     $ - msg2 
   
      msg3        db      'Number 2: ',0 
      lmsg3       equ     $ - msg3 
   
      msg4        db      10,'1. Add',10,0 
      lmsg4       equ     $ - msg4 
   
      msg5        db      '2. Subtract',10,0 
      lmsg5       equ     $ - msg5 
   
      msg6        db      '3. Multiply',10,0 
      lmsg6       equ     $ - msg6 
   
      msg7        db      '4. Divide',10,0 
      lmsg7       equ     $ - msg7 
   
      msg8        db      'Operation: ',0 
      lmsg8       equ     $ - msg8 
   
      msg9        db      10,'Result: ',0 
      lmsg9       equ     $ - msg9 
   
      msg10       db      10,'Invalid Option',10,0 
      lmsg10      equ     $ - msg10 
   
      nlinea      db      10,10,0 
      lnlinea     equ     $ - nlinea 
   
  section .bss 
   
      ; Spaces reserved for storing the values ​​provided by the user. 
   
      opc         resb    2 
      num1        resb    2 
      num2        resb    2 
      result      resb    2 
   
  section .text 
   
      global _start 
   
  _start: 
   
      ; Print on screen the message 1 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg1 
      mov edx, lmsg1 
      int 80h 
   
      ; Print on screen the message 2 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg2 
      mov edx, lmsg2 
      int 80h 
   
      ; We get num1 value. 
      mov eax, 3 
      mov ebx, 0 
      mov ecx, num1 
      mov edx, 2 
      int 80h 
   
      ; Print on screen the message 3 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg3 
      mov edx, lmsg3 
      int 80h 
   
      ; We get num2 value. 
      mov eax, 3 
      mov ebx, 0 
      mov ecx, num2 
      mov edx, 2 
      int 80h 
   
      ; Print on screen the message 4 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg4 
      mov edx, lmsg4 
      int 80h 
   
      ; Print on screen the message 5 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg5 
      mov edx, lmsg5 
      int 80h 
   
      ; Print on screen the message 6 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg6 
      mov edx, lmsg6 
      int 80h 
   
      ; Print on screen the message 7 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg7 
      mov edx, lmsg7 
      int 80h 
   
      ; Print on screen the message 8 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg8 
      mov edx, lmsg8 
      int 80h 
   
      ; We get the option selected. 
      mov ebx,0 
      mov ecx,opc 
      mov edx,2 
      mov eax,3 
      int 80h 
   
      mov ah, [opc]   ; Move the selected option to the registry ah 
      sub ah, '0'     ; Convert from ascii to decimal 
   
      ; We compare the value entered by the user to know what operation to perform. 
   
      cmp ah, 1 
      je add 
      cmp ah, 2 
      je subtract 
      cmp ah, 3 
      je multiply 
      cmp ah, 4 
      je divide 
   
      ; If the value entered by the user does not meet any of the above  
      ; conditions then we show an error message and we close the program. 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg10 
      mov edx, lmsg10 
      int 80h 
   
      jmp exit 
   
  add: 
      ; We keep the numbers in the registers eax and ebx 
      mov eax, [num1] 
      mov ebx, [num2] 
   
      ; Convert from ascii to decimal 
      sub eax, '0' 
      sub ebx, '0' 
   
      ; Add 
      add eax, ebx 
   
      ; Conversion from decimal to ascii 
      add eax, '0' 
   
      ; We move the result 
      mov [result], eax 
   
      ; Print on screen the message 9 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg9 
      mov edx, lmsg9 
      int 80h 
   
      ; Print on screen the result 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, result 
      mov edx, 1 
      int 80h 
   
      ; We end the program 
      jmp exit 
   
  subtract: 
      ; We keep the numbers in the registers eax and ebx 
      mov eax, [num1] 
      mov ebx, [num2] 
   
      ; Convert from ascii to decimal 
      sub eax, '0' 
      sub ebx, '0' 
   
      ; Subtract 
      sub eax, ebx 
   
      ; Conversion from decimal to ascii 
      add eax, '0' 
   
      ; We move the result 
      mov [result], eax 
   
      ; Print on screen the message 9 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg9 
      mov edx, lmsg9 
      int 80h 
   
      ; Print on screen the result 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, result 
      mov edx, 1 
      int 80h 
   
      ; We end the program 
      jmp exit 
   
  multiply: 
   
      ; We store the numbers in registers ax and bx 
      mov ax, [num1] 
      mov bx, [num2] 
   
      ; Convert from ascii to decimal 
      sub ax, '0' 
      sub bx, '0' 
   
      ; Multiply. AL = AX x BX 
      mul bx 
   
      ; Conversion from decimal to ascii 
      add al, '0' 
   
      ; We move the result 
      mov [result], al 
   
      ; Print on screen the message 9 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg9 
      mov edx, lmsg9 
      int 80h 
   
      ; Print on screen the result 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, result 
      mov edx, 1 
      int 80h 
   
      ; We end the program 
      jmp exit 
   
  divide: 
      ; IN THIS LABEL IS THE ERROR! 
   
      ; We store the numbers in registers ax and bx 
      mov dx, 0 
      mov ax, [num1] 
      mov bx, [num2] 
   
      ; Convert from ascii to decimall 
      sub ax, '0' 
      sub bx, '0' 
      ; Division. AX = DX:AX / BX 
      div bx 
   
      ; Conversion from decimal to ascii 
      add ax, '0' 
      ; We move the result 
      mov [result], ax 
   
      ; Print on screen the message 9 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, msg9 
      mov edx, lmsg9 
      int 80h 
   
      ; Print on screen the result 
      ; ALWAYS PRINTS 1 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, result 
      mov edx, 1 
      int 80h 
   
      ; We end the program 
      jmp exit 
   
  exit: 
      ; Print on screen two new lines 
      mov eax, 4 
      mov ebx, 1 
      mov ecx, nlinea 
      mov edx, lnlinea 
      int 80h 
      ; End the program 
      mov eax, 1 
      mov ebx, 0 
      int 80h