汇编程序19：二重循环

assume cs:code,ds:data,ss:stack
//指定数据段改为大写,形如[bx+si]型
data segment
    db 'ibm             '
    db 'dec             '
    db 'dos             '
    db 'vax             '
data ends

stack segment
    dw 0,0,0,0,0,0,0,0
stack ends

code segment
    start:
          mov ax,data
          mov ds,ax
          mov ax,stack
          mov ss,ax
          mov sp,16
          mov bx,0
          mov cx,4
        s:
          push cx
          mov si,0
          mov cx,3
       s0:
          mov al,[bx+si]
          and al,11011111b
          mov [bx+si],al
          inc si
          loop s0

          add bx,16
          pop cx
          loop s
    mov ax,4c00h
    int 21h
code ends

end start