i will use 10.4 as a guide to start with
things you will need external harddrive (firewire is best but usb will do)


I had an old ibook and a couple of powerbooks i wanted to upgrade to tiger, so after much trial and error i manage to get it working on both types of machines, you can find the minimum spec on the apple website, but generally you will need 512 MB ram as a basic, and a harddrive bigger than 7 gig (this guide also works for leopard)

Turn your harddrive into a bootable Tiger installation disk

1 Using Disk Utility, format (Erase) the harddrive.
Under Volume Format make sure you click on 'Mac OS Extended'
Under Name: type in what ever you want to call your harddrive.

When that is completed Click on Restore.
under Source choose the Mac OS X Install DVD .dmg
under Destination choose the external harddrive which you just erased, click restore and wait until the image restores onto the harddrive

When the restore is done, reboot your system hold down the option key and follow the instructions to install it, hope this is of help to someone , please be kind as its my first tutorial :)



For those using the firewire option, you can use your powerbook in firewire mode as the 'harddrive', which is a lot easier the disk image will be copied to your powerbook or ibook then reboot as norman (no need to hold down option key) follow on screen setup instructions.