p131_6_4.asm

ZHUYAO ZSHI LAI JIECHUADE LAIDE

data  segment
      buf   db 69h
      buf1  db ?
      buf2  db ?
      buf3  db ?
      buf4  db ?
data  ends
code  segment
      assume ds:data,cs:code
main  proc far
start:push ds
      mov ax,0
      push ax
      mov ax,data
      mov ds,ax
      mov al,buf
      mov cl,4
      shr al,cl
      mov buf2,al
      or al,30h
      mov buf4,al
      mov al,buf
      and al,0fh
      mov buf1,al
      or al,30h
      mov buf3,al
      ret
main  endp
code  ends
      end start