You can adjust the trackpad settings via the Mouse Control Panel
(notice icons in attached example)… OR acquire original install disks
for your specific iBook - but I’m uncertain that Trackpad extension /
control panel is even there under OS 9.
UPDATE:Trackpad control panel
is there with Apple OS 9.0 retail install disk.
Just did a quick install and then rebooted into OS 9.2.2 and drug
the control panel from 9 to 9.2.2 and it doesn’t seem to mind.
CP attached.
*Apple updates for 9.1 & 9.2 may install a later version
over the v7.5.7 attached here below.
AND yes, beginning with Apple-sourced OS 9.1 update,
Trackpad control panel goes from v7.5.7 to
v9.0.4(with no further changes under OS 9.2.1 or OS 9.2.2).