I have an original G3 300mhz Powermac. Now I know about an issue these have with the ATA controller when using 2 drives at the same time. But I also heard there is a hard drive limit and I want to put a new hard drive in it. What is that limit, is it 120GB? I was going to buy a 40GB to be sure and have it as the only drive. Anybody want to clarify this for me? Thank you in advance.