Some of those G3 iMacs required OS 9 to be installed
and resident upon the first
8 GB partition of the drive.
And your problem might actually stem from not
checking that “Install OS 9 drivers” box in Tiger’s Disk
Utility… if you used that to format and partition your
SSD. If this is the case, you might try again to use
Tiger’s Disk Utility to reformat and partition the SSD,
making certain to check that box… to see if an OS 9
installer would then recognize the SSD for an OS 9
installation.
If that doesn’t work, then…
If you’ve another machine that you can format and
partition your SSD in (outside of your iMac) then you
might try that… multi-partitioning the SSD with the first
8 GB partition for OS 9 and maybe the rest for Tiger.
I have done this before using 4 partitions; one 8 GB
for OS 9, one vacant for OS 9 file writes, then one for
Tiger and the remainder for Tiger file writes. You
determine what size you prefer the other partitions to
be (and how many). BUT using OS 9’s Drive Setup
1.9.2 or 2.1 from whatever OS 9 installer you choose,
first to format and partition the entire SSD before
placing it back in the iMac.
And as a possible further complication… when
installing Tiger (or immediately during, or before
reboot) be certain to exclude Spotlight (from System
Preferences > Spotlight > Privacy) to restrict Spotlight
from ever accessing your OS 9 partition or the OS 9
file write partition in order to avoid the ever-common
BTree error corruption associated with not taking this
step.
Also, under Tiger System Prefs > Classic… I always
check the box “Warn before starting Classic” as I
never run “Classic”. If I want to run OS 9 or OS 9 apps,
I boot into OS 9. (Just as I drag files from OS 9 to OS
X - but never the inverse.)
Good luck! YMMV
And welcome to the Forum!