|
发表于 2012-7-28 15:26:16
|
显示全部楼层
我的代码如下:
assume cs:code,ds:data
data segment
db "Beginner's All-purpose Symbolic Instruction Code.",0
data ends
code segment
start:
mov ax,data
mov ds,ax
mov ax,0b878h
mov es,ax
mov si,0
mov di,0
call letterc
mov ax,4c00h
int 21h
letterc:
mov al,[si]
cmp al,0
je exit
cmp al,'a'
jb s0
cmp al,'z'
ja s0
and al,11011111b
mov byte ptr [si],al
s0:
;显示白底黑字
mov byte ptr es:[di],al
mov byte ptr es:1[di],01110000b
inc si
add di,2
jmp short letterc
exit:
ret
code ends
end start
|
|