Tiger Requirements...
To use Mac OS X 10.4 Tiger, your Macintosh needs:
* A PowerPC G3, G4, or G5 processor
* Built-in FireWire
* At least 256 MB of RAM (I recommend 1GB minimum)
* DVD drive (DVD-ROM), Combo (CD-RW/DVD-ROM) or SuperDrive (DVD-R) for installation
* At least 3 GB of free disk space; 4 GB if you install the XCode 2 Developer Tools (I recommend 20GB minimum)
http://support.apple.com/kb/HT1514
See Tom's, (Texas Mac Man), great info on where/how to find/get Tiger...
http://discussions.apple.com/thread.jspa?messageID=9755670�
Or Ali Brown's great info on where/how to find/get Tiger...
http://discussions.apple.com/thread.jspa?messageID=10381710#10381710
Leopard requirements/10.5.x...
* Mac computer with an Intel, PowerPC G5, or PowerPC G4 (867MHz or faster) processor
minimum system requirements
* 512MB of memory (I say 2GB at least)
* DVD drive for installation
* 9GB of available disk space (I say 30GB at least)
On this one you can call Apple & see if they have any left.