使用汇编实现字符串的大小写转换

assume cs:codesg,ds:datasg

datasg segment
 db 'BaSiC'
 db 'iNforMaTiOn'
datasg ends

codesg segment
 start: mov ax,datasg
  mov ds,ax
  
  mov cx,5
  mov bx,0
  
 s1: mov al,ds:[bx]
  and al,11011111b
  mov ds:[bx],al
  inc bx
  loop s1
 
  mov cx,11
  mov bx,5
  
 s2: mov al,ds:[bx]
  or al,00100000b
  mov ds:[bx],al
  inc bx
  loop s2
  
  mov ax,4c00h
  int 21h

codesg ends

end start