If you have a PowerPC based Mac, then read on. But if you have an Intel mac, stop reading, this doesn’t apply to you. Unless you want to read it, then who am I to stop you? If you have a PowerPC Mac with Mac OS X installed, and want to use the Classic Environment so you can use your pre-OS X apps on it, but don’t have Mac OS 9 installed, or don’t have a Mac OS 9 CD, or system restore CD’s with Mac OS 9 in it, then your not out of luck. In fact, your luck is about to begin. Just visit Macintosh Garden, and search there. Here is the link: http://www.macintoshgarden.org/apps/operating-systems
Also while you’re there, and happen to have even older macs, like older PPC systems, or even 68k based systems, you can find, a System 7.6.1 disk! Last time I went there I think I found like three Mac OS 9 downloads. Enjoy!