Destination volume needed to install OS9?

Your issue suggests that Mac OS 9 drivers weren't installed on the disk when it was last erased. In this situation, you need to either erase the disk again with the drivers(which requires that you have the Mac OS X installation disk), or purchase an external drive, reformat it to Mac OS Extended if necessary, and install Mac OS 9 onto that. You will get much better performance from a FireWire disk than an USB one on that machine.

(12137)

This means that someone reformatted the iMac's hard drive and didn't include the OS 9 drivers.

1 back up everything

2 reformat, this time clicking on the 'include OS 9 drivers' checkbox

3 restore from your backup

4 install OS 9.

Alternatively, get an external FireWire (NOT USB...) drive, format that with the OS 9 driver checkbox selected, and install OS 9 on that.

Notes:

1 your iMac comes with FireWire 400 & USB 1.1. USB drives will be extremely slow on your machine. Some Macs can boot from USB devices using OS 9; no PPC Macs can boot from USB devices using OS X. I understand that it might be possible to boot from USB devices using OS X on an Intel Mac. I have not verified this.

2 if you have an external drive formatted including the OS 9 drivers, you can install OS 9 on that drive. However, when the Mac boots OS 9, your internal drive will not be visible. This is because it has no OS 9 drivers. Booting back into OS X on the internal drive would require gymnastics. For a simple life, you might want to install OS 9 drivers on the internal drive, too. Sorry, but the only Apple-supported way to do that is to reformat the drive. Back up first.

3 if all you want to do is run Classic, not boot OS 9, the quick & dirty way to do it is to find a Mac, preferably a Mac of roughly the same type as yours, which has OS 9 installed. Boot your Mac and then attach the other by FireWire and boot it in Target Disk Mode. Copy the OS 9 System Folder over to your Mac. Alternatively, attach both Macs to a network and copy from the other Mac to your Mac over the network. Or burn the OS 9 System Folder onto a CD and hand-carry it to your Mac and copy from the CD. You cannot generate a bootable OS 9 System Folder this way unless you already have OS 9 drivers on your hard drive (which you don't) and unless the other Mac is essentially identical to yours. In particular the video subsystems of various Macs are different, and OS 9 from one Mac won't boot or won't boot properly on another. (Example: OS 9 from an early eMac will boot on an early iMac G4, but the display will be next to unusable. OS 9 from an early iMac G4 will not boot an early eMac. Period. Wanna guess how I know this?) Classic doesn't care about the video subsystem, OS X is doing all of the low-level work anyway.

Your issue suggests that Mac OS 9 drivers weren't
installed on the disk when it was last erased. In
this situation, you need to either erase the disk
again with the drivers(which requires that you have
the Mac OS X installation disk), or purchase an
external drive, reformat it to Mac OS Extended if
necessary, and install Mac OS 9 onto that. You will
get much better performance from a FireWire disk than
an USB one on that machine.

Is that model iMac one of those which can boot OS 9 from USB?

Is that model iMac one of those which can boot OS 9 from USB?

Yes, all slot-loading iMac G3s can boot Mac OS 9 from an USB drive.

(12252)

I have just had to do an erase and install of Tiger on G4 Quicksilver. I need OS 9 for only one application. Can I install it over Tiger or should I have installed it first? The OS 9 installer warned me that I needed to do a Clean Install. Will this wipe out my Tiger system?

I have just had to do an erase and install of Tiger
on G4 Quicksilver.

Erase & installs are rarely necessary. I hope you made a full backup before doing the e&i. In most cases an archive install will do everything you need to do... but you should do a full backup before the ai anyway. Just in case.

I need OS 9 for only one
application. Can I install it over Tiger or should I
have installed it first? The OS 9 installer warned me
that I needed to do a Clean Install. Will this wipe
out my Tiger system?

If you need _OS 9_, you have to have the OS 9 drivers installed on your hard drive. When you did the erase and install, did you click the 'install OS 9 drivers' checkbox? If you did, you have the drivers and can install OS 9. Installing OS 9 should not erase your OS X install unless you tell it to, but you should have a backup before you do major operations such as installing an OS. Just in case. If you did not, then you don't have the drivers, and in order to get the drivers you will have to reformat your hard drive, either using the OS X installer and this time click on the 'install OS 9 drivers' checkbox, or with OS 9's Drive Setup utility.

If you only need Classic, and you did a full backup before the erase and install, and you had the OS 9 System Folder on that machine before the e&i, then you can restore the OS 9 System Folder from your backup and Classic will work. If you don't have the OS 9 System Folder backed up you can just copy a System Folder over from another Mac and that should do, so long as the other Mac is a G4 of some kind.

If you have no access to another Mac, you'll have to install OS 9. Back up first.