为什么我这段实现不了应有的功能
程序是将小写字母转换成大写字母!
assume cs:code
data segment
db 'conversation'
data ends
code segment
start:mov ax,data
mov ds,ax
mov si,0
mov cx,12
s:mov al,[si]
call captical
inc si
loop s
mov ax,4c00h
int 21h
captical:and al,11011111b
ret
code ends
end start