;在SRTRING开始的100个单元中存放着一个字符串,编一程序测试该字
;符串中是否存在数字,如果存在把CL的第5位置1,否则将该位置0.
;并在屏幕上显示CL的内容.
data segment
org 1000h
string db 'F5'
string1 db 95 dup(?) 
data ends
stack segment stack
h2 db 100 dup(?)
stack ends
code segment 
assume cs:code,ds:data,ss:stack 
start:mov ax,data
      mov ds,ax
      lea si,string
      lea cx,string1
      mov bl,8   
      sub cx,si
l1:   mov al,[si]
      cmp al,'0'
      jb l2
      cmp al,'9'
      jbe exit
l2:   inc si
      loop l1
      and cl,0efh     ;0efH=11101111B   
      jmp l3     
exit: or cl,10h       ;10H=00010000B
      mov al,cl
l3:   cmp bl,0
      je x2 
      dec bl
      shl al,1 
      jc x1
      call z1
      jmp l3
x1:   call z2
      jmp l3
x2:   mov ah,4ch
      int 21h
z1    proc 
      push ax
      push bx
      push cx
      push dx
      mov dl,30h 
      mov ah,2 
      int 21h 
      pop dx 
      pop cx
      pop bx
      pop ax
      ret 
z1    endp 
z2    proc 
      push ax
      push bx
      push cx
      push dx
      mov dl,31h 
      mov ah,2 
      int 21h 
      pop dx 
      pop cx
      pop bx
      pop ax
      ret 
z2    endp 
code ends
    end start