I saw a compatibility chart on the Apple website http://support.apple.com/kb/ht1835 that says that the Powerbook 5300 can support OS 9.1. I have several PowerBook 5300s and a 190cs and was wondering if anyone has tried this yet? I figure it might be a good way to squeeze a few more bits of life out of these old collection pieces of mine considering they have PCI ports (if I am remembering correctly, I would have to look). Can anyone verify that this works? Thanks!