Hello Keith,You can install Tiger on a G3 iMac as long as its processor speed is equal to or greater than 350 MHz. However, you said that your Tiger disks did not work, could this be because you were using the disks which came with your computer? These are specific to the particular model of computer they ship with. You should try the installation with a standard Tiger DVD. The retail version of Tiger does not work on Intel Macs as one or two people found out to their cost.
Cheers, Anne
