org 07c00h;
mov ax,cs;
mov ds,ax;
mov es,ax;
call DispStr;
jmp $;
DispStr:
mov ax,BootMessage;
mov bp,ax;
mov cx,16;
mov ax,01301h;
mov bx,000ch;
mov dl,0
int 10h;
ret;
BootMesage:db "HELLO, OS WORLD!"
TIMES 510-($-$$) db 0;
dw oxaa55;
这段程序真么老是提示 bootmessage未定义?
该怎么定义