samples-with-macros/gcd-input.asm

   1 .model      small
   2 ;greatest common divisor, with input from terminal
   3 data segment
   4   tempStr db "        "
   5   prompt  db "num?$"
   6   promptr db "RES $"
   7   m     dw  0
   8   n     dw  0
   9
  10 data ends
  11 ;#macro-commands-start
  12 ; print a string on screen
  13 print_str macro s
  14     push ax
  15     push dx
  16     mov dx, offset s
  17     mov ah, 09
  18     int 21h
  19     pop dx
  20     pop ax
  21 endm
  22
  23 ; new line
  24 print_new_line macro
  25     push ax
  26     push bx
  27     push dx
  28     mov ah,03
  29     mov bh,0
  30     int 10h
  31     inc dh
  32     mov dl,0
  33     mov ah,02
  34     int 10h
  35     pop dx
  36     pop bx
  37     pop ax
  38 endm
  39
  40 ; write a single char
  41 print_char macro c
  42     push ax
  43     push dx
  44     mov ah, 02
  45     mov dl, c
  46     int 21h
  47     pop dx
  48     pop ax
  49 endm
  50
  51 ; finish the execution
  52 end_execution macro
  53     mov ax, 4c02h
  54     int 21h
  55 endm
  56
  57 ; Konvertovanje broja u string
  58 inttostr macro num1 str1
  59    push ax
  60    push bx
  61    push cx
  62    push dx
  63    push si
  64    mov ax, num1
  65    mov dl, '$'
  66    push dx
  67    mov si, 10
  68 petlja2:
  69    mov dx, 0
  70    div si
  71    add dx, 48
  72    push dx
  73    cmp ax, 0
  74    jne petlja2
  75
  76    mov bx, offset str1
  77 petlja2a:
  78    pop dx
  79    mov [bx], dl
  80    inc bx
  81    cmp dl, '$'
  82    jne petlja2a
  83    pop si
  84    pop dx
  85    pop cx
  86    pop bx
  87    pop ax
  88 endm
  89
  90 print_num macro num
  91         inttostr num,tempStr
  92         print_str tempStr
  93 endm
  94 read_num macro num
  95         read_str tempStr,6
  96         strtoint tempStr,num
  97 endm
  98
  99 ;read into a buffer, inc the special 0 and 1 bytes
 100 ;fixes it into a $ terminated string
 101 read_str macro strbuff, strlen
 102     LOCAL copystr
 103     push ax
 104     push bx
 105     push cx
 106     push dx
 107     push si
 108     mov bp, sp
 109     mov dx, offset strbuff
 110     mov bx, dx
 111     mov ax, strlen
 112     mov byte [bx] ,al
 113     mov ah, 0Ah
 114     int 21h
 115     mov si, dx
 116     mov cl, [si+1]
 117     mov ch, 0
 118 copystr:
 119     mov al, [si+2]
 120     mov [si], al
 121     inc si
 122     loop copystr
 123     mov [si], '$'
 124     pop si
 125     pop dx
 126     pop cx
 127     pop bx
 128     pop ax
 129 endm
 130
 131 ;ascii to actual number
 132 strtoint macro inStr,outNum
 133     LOCAL mainloop,end
 134     push ax
 135     push bx
 136     push cx
 137     push dx
 138     push si
 139     mov bp, sp
 140     mov bx, offset inStr
 141     mov ax, 0
 142     mov cx, 0
 143     mov si, 10
 144 mainloop:
 145     mov cl, [bx]
 146     cmp cl, '$'
 147     je end
 148     mul si
 149     sub cx, 48
 150     add ax, cx
 151     inc bx
 152     jmp mainloop
 153 end:
 154     mov outNum, ax
 155     pop si
 156     pop dx
 157     pop cx
 158     pop bx
 159     pop ax
 160 endm
 161 ;#macro-commands-end
 162
 163 .code
 164
 165 start:
 166     mov ax,@data
 167     mov ds,ax
 168     print_str prompt
 169     read_num m
 170     print_new_line
 171     print_str prompt
 172     read_num n
 173     print_new_line
 174
 175             mov   ax,n
 176             mov   bx,m
 177
 178 compare:
 179             cmp   ax,bx
 180             je    exit ;exit since they're equal
 181             ja    greater
 182             sub   bx,ax
 183             jmp   compare
 184
 185 greater:
 186             sub   ax,bx
 187             jmp   compare
 188
 189 exit:
 190 ;exit out of the program
 191     mov n,ax
 192     print_str promptr
 193         print_num n
 194 ; print out a result
 195             end_execution
 196
 197 .stack
 198 end start