I must keep OS9 because I have huge data base running on an old program Cummulus, no update possible.

Using data only very seldom, it's basically an archive.

Thought of Mac Mini 500GB, but for storage only??

Question

Can I run 2 operating systems on the same machine or do I need 2 machines.

Goal to keep OS more or less inactive plus have the latest OS for Mac

From my question you see I'm totally naive,

I must keep OS9 because I have huge data base running on an old program Cummulus, no update possible.

Using data only very seldom, it's basically an archive.

Thought of Mac Mini 500GB, but for storage only??

Question

Can I run 2 operating systems on the same machine or do I need 2 machines.

Goal to keep OS more or less inactive plus have the latest OS for Mac

From my question you see I'm totally naive,

Yes you can: I assume you want to run 0S9 on the Mini which would be a Mac intel.

Go here: <http://theappleblog.com/2006/07/01/classic-on-intel-macs-courtesy-of-sheepshaver>

No need to use a Mini for storage only. Would suggest getting a 250 or 500 Gig USB or Firewire

drive with the Mini. Use that for storage and use the Mini for it's excellent speed and functions.

To run OS 9 you need an older Mac with a PowerPC processor. To run the current version of OS X, Snow Leopard, you need a newer Mac with an Intel processor.

The good news is that Snow Leopard will run something called Rosetta, which is an OS9 emulator, allowing PowerPC applications to run on an Intel Mac with OS X installed. So go ahead and buy the shiny new Mac. When you need that database, you will be able to access it. Just remember that emulation does slow down the app, but today's Macs are so fast it hardly matters. My husband plays an ancient game, Maelstrom, on his new Mac Pro. The first time he tried to run it he got a message telling him it was an OS9 game, and would he like to install Rosetta to run it? He clicked okay and has been playing happily since.

So no need to get fancy with dual operating systems. It will Just Work.

cathyy, you are confusing Rosetta (= ability to run PPC programs on Intel Macs) with Mac OS Classic (= runtime environment for OS 9 and OS 9 apps).

Classic doesn't officially run on any Intel Mac, it only runs on PPC Macs, and only on OS X 10.4 or lower. I have an old iBook and an old PowerBook that could do it. But.. you can use sheepshaver, as thpthai2 has pointed out see his link above - pretty amazing, but it doesn't look 100% straightforward. For example, I don't have a OS 9.0 install CD so I couldn't do this.

References:

http://www.apple.com/rosetta/

http://en.wikipedia.org/wiki/Classic_Environment

BTW for your purposes it would probably best if you got hold of a G5 PowerMac. Those things are built to last, and they are really very fast, and have tons of memory, and can run Classic. You could dual boot with 10.4 (for Classic) and 10.5. I don't think OS 9 would install on one, it wouldn't have the drivers required for the hardware.