The drive from the G4 will not work in the G5 as the connections are entirely different.
The G4 drive is an IDE device and uses a much wider connector and power plug.
The G5 drive, on the other hand, is a SATA device and uses very small, not even close, connectors.
If you really want to use the G4 drive, then purchase a USB IDE hard drive enclosure and mount the drive inside it.
Connect to the USB port and off you go.
I recently obtained a G5 (powermac 7.2 running 10.5.8) after being exiled on a pc for two years. I opened a CD containing files I saved from my previous Mac (a G4 running 10.3.9) on the G5. Most of the files opened with no problem. However, nearly all of the articles I wrote (using Appleworks, saved as RTF documents) showed up on the G5 as a "Unix executable file." I don't even know what that is, except for the reference to Unix.
I know very little about Unix. Is there anything I can do to salvage these documents?
As a secondary question, will the hard drive from the G4 work if I install it in the G5?
Thank you for your help.