So I just bought an old powermac g4. When I first booted it, it had Tiger on it. But not knowing much about old macs it looked like it also had os9 on it cause I could choose to boot from a os9 folder. So without thinking I choosed to boot from it thinking it would boot into os9! But nope. All I get now when I try to start it is a grey screen with a small floppy disk icon with a flashing question mark on it! I have tried to boot holding down alt, but it only shows one hard drive. Also, I don't have any mac os cd's to boot from! Can anyone please help me with this?