or使数值变ASCII码?
code segment assume cs:code start: mov ah,1 int 21h sub al,30h ;ASCII码变数值 mov bl,al mov dl,'+' mov ah,2 int 21h mov ah,1 int 21h sub al,30h ;ASCII码变数值 xor ah,ah ;ah清零 add al,bl aaa ;BCD吗的加法校正指令 mov bx,ax mov dl,'=' mov ah,2 int 21h mov dl,bh or dl,30h ;数值变ASCII码 mov ah,2 int 21h mov dl,bl or dl,30h ;数值变ASCII码 mov ah,2 int 21h mov ah,4ch int 21h code ends end start
;or是逻辑或运算指令,在这里使用or使数值变ASCII码,这是为什么?