Thanks!
If you're copying over the System folder, there's a chance it's not being "Blessed". If that's the case there's a terminal command you can run to bless the OS9 system folder from OSX.
As long as the Mac OS 9 disk drivers are installed the rest of your setup sounds good.
Can you please try these ROMs. If you place them in the OS9 System Folder it should eliminate the need to run those Open Firmware commands. I modified the iMic ROM to run the OFW command as part of the boot script.
Test ROM
Use this ROM if the above works:
Screamer ROM
If you don't get any crashes with those ROMS, then I would suspect it's something to do with the System Folder being unblessed or partitioning issues.
If your system does crash, reboot and hold the alt key and boot from OSX, then restore the original Mac OS ROM.
iMac G3s are a pain with multi-partition SSDs and I had a lot of trouble with this. The G4 may be similar. This page may also be helpful: iMac G3 Dual Bootable SSD Setup/
Hello!!! Thank you so much for your instructions and help.
I downloaded your two ROMs, but they weren't working, so I booted the iMac in Target Disk mode and, from the Mac Mini running OS 9, ran First Aid on the iMac disk. This fixed it and caused the OS 9 disk image with your ROMs to appear when booting with ALT.
With the first ROM, the first thing it does is open the CD tray and then enter Open Firmware. With the second ROM, the CD doesn't open, but it also enters Open Firmware. I've attached a photo.
Since you were right, and that I had the wrong system folder because I had copied it from OSX (and that it had worked for me before), I tried another ROM file, which I think is the "Unsupported" one, and which I attached below.
It booted with this ROM, but I have two issues (I'd appreciate other things I need to check). First, I have no internal sound, and second, I only had 256 colors and no 3D acceleration.
I haven't gotten anywhere with the sound, but with the graphics, changing the NVidia drivers from version 2.3 to version 3.2 or 3.5 allows me to get millions of colors, but I still don't have 3D acceleration. Since it's a more modern GF4 chip and AGPx8, there may not be drivers for OS9.
Do you know if these problems can be solved?