The new drive has the proper jumper setting, is in the middle (and correct) ATA cable position, and is recognized and has been formatted by the computer. Unfortunately, when i boot the G4 the blinking globe appears for about ten seconds, and then the "no OS" folder appears for another ten seconds before OS X successfully loads and the computer operates normally, with both drives functioning fine. Almost a success story, but it makes me nervous. Thanks for all the help so far!