constant expected 编译错误。
assume cs:code
code segment
start:
mov ah,2ch
int 21h
mov ch,cl
mov al,4
shr ch,al
and cl,00001111b
mov dl,ch
mov ah,2
int 21h
mov dl,cl
mov ah,2
int 21h
mov ax,4c00h
int 21h
code ends
end start
编译后在shr ch,al处出现constant expected的错误,请问,这句哪错了。