Hi, otto99 -
Every Mac has a minimum OS which it can use for booting purposes. It is quite probable that the OS 9 disks you have from the older G3 iBook are insufficient to boot the G3 600MHz model you acquired.
In addition, disks that come with a Mac are usually specific to that model, and are not capable of booting a different model machine, even one in the same class. These OEM disks usually do not contain a universal installer; the resources of software items available to the installer is not a complete, all-machine set. Although your G3/600 model is also an iBook, its hardware components are not the same as the earlier one.
Even if you could install OS 9 from your older disks via FwTDM, it probably will not work - if the CD can not boot the Mac, the OS 9 version it installs will also not be able to boot the machine.
A G3 600MHz iBook can be one of three different iBook models - iBook (late 2001); iBook (14"); or iBook (16 VRAM). This KBase article can help you identify which model you have -
http://support.apple.com/kb/HT1772
Which model you have is important -
• iBook (late 2001) - came with OS 9.2.1, can use a retail OS 9.2.1 Install CD
• iBook (14") - came with OS 9.2.1, probably can not use a retail OS 9.2.1 Install CD
• iBook (16 VRAM) came with OS 9.2.2, can use only the original OS 9.2.1 Software Install CD that came with it
The significance is the recourse available to you.
If your machine is one of the first kind, a (late 2001) model, you can get a retail OS 9.2.1 Install CD and use it to install a bootable OS 9. You can get such disks at places like -
http://store.yahoo.com/hardcoremac/index.html
If your machine is one of the second kind, a (14") model, you may be able to use a retail OS 9.2.1 Install CD, or you may not - the information available is a bit contradictory. If it can not use a retail OS 9.2.1 Install CD, the only other choice is to locate an original OEM Software Install CD for that machine model.
If your machine is one of the third kind, a (16 VRAM) model, your only choice is to acquire an original OEM Software Install disk for that specific machine.
You might contact the person(s) you got the machine from to see if you can get its original disk set. Since OEM disks are not much use other than with the machine with which they came, it is customary to include them with the sale/transfer of a machine to another person.