Q: How can I get tiger installation discs?

Apple no longer has them.

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...

https://discussions.apple.com/message/15305521#15305521

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 1.5GB for PPC at least, 2-3GB minimum for IntelMacs)

    * DVD drive for installation

    * 9GB of available disk space (I say 30GB at least)

Classic/OS9 Apps no longer supported.

Trouble is Apple no longer sells it, check eBay & such for the Retail version, not the Gray Discs...

http://www.ebay.com/sch/i.html?_nkw=mac+os+x+leopard+retail+10.5

There are workarounds if the 867MHz CPU is the only hangup...

http://sourceforge.net/projects/leopardassist/

http://lowendmac.com/osx/leopard/unsupported.html

List of Applications Not Compatible with Leopard...

http://guides.macrumors.com/List:Applications_Not_Compatible_with_Leopard

If you are currently running OS 10.4.11, you are running Tiger. The next higher OS (and the max for PowerPC processor Macs)  is Leopard 10.5.x.

In the menu, far left, cilck on the Apple & select About This Mac. What does it show for OS and processor speed?

 Cheers, Tom

Your Mac can run Leopard OS 10.5.x.

Mac OS X 10.5 Leopard installation system requirements

http://support.apple.com/kb/TA24950

Leopard is no longer available at the Apple Store but may be available by calling Apple Phone Sales @ 1-800-MY-APPLE (1-800-692-7753).

If you can't obtain a retail install DVD from Apple, look on eBay or Google the installer part numbers to possibly find at an on-line store. Here's what to look for:

MB427Z/A  Leopard 10.5.1 install DVD

MB576Z/A  Leopard 10.5.4 install DVD

MB021Z/A  Leopard 10.5.6 install DVD (single user)

MB022Z/A  Leopard 10.5.6 install DVD (5-user family pack)

Installing Mac OS X 10.5 Leopard

http://support.apple.com/kb/HT1544

Mac OS X 10.5 Leopard Installation and Setup Guide

http://manuals.info.apple.com/en/leopard_install-setup.pdf

After you install the base 10.5, download & install the 10.5.8 combo update at http://support.apple.com/downloads/Mac_OS_X_10_5_8_Combo_Update

The DVD should look like this

Caution - Leopard does not support classic mode. So, if you currently open OS 9 apps in classic mode, you won't be able to do this if you upgrade to Leopard.

 Cheers, Tom