中间变量
M_CRLF MACRO ;回车MOV DL, 0AH
MOV AH,02H
INT 21H
MOV DL, 0DH
MOV AH,02H
INT 21H
ENDM
ws macro z
local aa3 ,bb3 ,aa4 ,bb4
mov dx, cx
mov al, z ; 这里将Z的值赋给了AL，对z
;的值作变化 ，AL没有做改变
and z, 0f0h
mov cl, 04h
shr z, cl
mov cx, dx
cmp z, 09h
ja aa3
add z, 30h
jmp bb3
aa3: add z, 37h
bb3: mov dl, z
mov ah, 02h
int 21h
and al,0fh ; 这里取AL的低字节即要取Z的
;低字节 cmp al,09h
ja aa4
add al, 30h
jmp bb4
aa4: add al, 37h
bb4: mov dl, al
mov ah,02h
int 21h
endm
sum macro x, y
add x, y
ws x
M_CRLF
endm
DATA segment
buf1 db 11h,12h,13h,14h,15h,16h,17h,18h,19h
buf2 db 21h,22h,23h,24h,25h,26h,27h,28h,29h
DATA ends
code segment
assume cs:code , ds:DATA
start: mov ax, DATA
mov ds, ax
mov es, ax
mov si, offset buf1
mov di ,offset buf2
mov cx, 09h
done: mov al, [si]
mov bl, [di]
inc si
inc di
sum al, bl
loop done
mov ah, 4ch
int 21h
code ends
end start
为什么结果会是这样的：
33
33
33
33
33
33
33
44
44
而将这两句改为
MOV BL, Z
MOV AL, BL 结果正确了，为什么不可以对AL 直接取字节，要用一个中间变量呢？
