chp2_9-4.asm

关于8086汇编的一些作业程序

stack segment stack'stack'
      dw 32 dup(?)
stack ends
data segment
NUM DB 25H,3EH,6AH,08H
data ends
code segment
begin proc far
      assume ss:stack,cs:code,ds:data
      push ds
      sub ax,ax
      push ax
      mov ax,data
      mov ds,ax
      LEA BX,NUM
      MOV AL,[BX]
      XCHG AL,[BX+3]
      MOV [BX],AL

      MOV AH,[BX+1]
      XCHG AH,[BX+2]
      MOV [BX+1],AH
      ret
begin endp
code ends
     end begin