Follow this quick steps to setup your testing env:
You need 2 primary partitions, 10 gigs each is far enough.
JaS 10.4.6/10.4.7 DVD
JaS 10.4.8 update (get from previous post)
You need to have a running JaS 10.4.8 on the primary partition.
Install from DVD and upgrade to 10.4.8.
Now boot to your primary JaS OS X 10.4.8.
Just put any JaS 10.4.4 – 10.4.7 DVD in your drive and run the following package: /System/Installation/Packages/OSInstall.pkg
Choose to install on your second partition.
Follow the wizard and choose customize button, and uncheck all patches.
Then click next, next…
You should have now an unpatched 10.4.4 system installed on second partition.
Don’t try to boot right now, it won’t work.
Next step is to get the apple combo update: MacOSXUpdCombo10.4.8Intel.dmg
Extract the MacOSXUpd10.4.8Intel.pkg to your Desktop
and right-click on it and choose Show Package Content.
Browse to Content/Resources and drag ‘n’ drop the InstallationCheck file to the trash.
Now double-click the pkg and install to the second partition.
If you can’t select the second partition while installing 10.4.8 update,
just do the following:
Open a terminal and type sudo -s
Enter your root password and type the following command:
ditto -x Desktop/MacOSXUpd10.4.8Intel.pkg/Contents/Archive.pax.gz /Volumes/partition2/
where partition 2 is the name of your second partition.
Well, this can boot to single user mode for sure.
But if you want to test further, you need the 10.4.8 decrypts…