task1__6_6.2/main.asm

   1 ;
   2 ; Copyright (C) 2008  Alexander Potashev
   3 ;
   4 ; Calculating of the number of zero words of 10 top words in the stack
   5 ;
   6
   7 .model small
   8 .code
   9
  10 start:
  11         push 0
  12         push 20
  13         push 30
  14         push 40
  15         push 50
  16         push 60
  17         push 70
  18         push 0
  19         push 90
  20         push 0
  21
  22 ;-----------------------
  23         mov ax, dgroup
  24         mov ds, ax
  25
  26 ;-----------------------
  27         mov bp, sp      ; using "bp" to access stack variables
  28         mov ax, 0
  29
  30         mov cx, 10
  31 next_word:
  32
  33         cmp word ptr [bp], 0    ; educational way
  34         jne not_zero            ;
  35         inc ax                  ;
  36 not_zero:                       ;
  37
  38 ;       mov dx, [bp]            ; --- another, "cheat" way (without "cmp") ---
  39 ;       sub dx, 1               ; CF=1 if dx=0
  40 ;       adc ax, 0               ;
  41
  42         add bp, 2
  43         loop next_word
  44
  45 ;-----------------------
  46 ; now "ax" contains the result (possible values: 0..10)
  47         lea dx, text
  48
  49         cmp ax, 10
  50         je result_10
  51
  52         inc dx
  53         add al, '0'
  54         mov text[1], al
  55
  56 result_10:
  57
  58         mov ah, 09h
  59         int 21h
  60
  61 ;-----------------------
  62
  63         add sp, 20
  64
  65         mov ax, 4c00h
  66         int 21h
  67
  68 .data
  69 text    db      "10", 13, 10, '$'
  70
  71 .stack 256
  72
  73 end start
  74