[Swordmaker]

Mac OS 9 runs on Mac OS X up to Panther, Mac OS 10.3. New Macs have newer versions of OS X that do not run Mac OS 9. I have gigabites of BookUp files that run under Mac Classic (OS 9) only. I also have lots of games and some outstanding work applications for OS 9. I would have to spend a lot of money trying to reproduce this capability, in those cases when it is possible to do so.

Classic works well under OS X.4 Tiger but only on PowerPC Macs, not Intel. It does not come with Tiger but will work with the already installed version of Classic from Panther. It was removed completely with Leopard. Apple is not responsible for the writers of BookUp's chess programs for not upgrading their product. Apple has made every effort to make it easy to upgrade.

Microsoft makes backwards compatibility one of the primary sales points of their newer OSes... but that may be more of a curse than a blessing as the complexity of maintaining legacy code gets in the way of designing a modern OS. So, yes, Microsoft does do legacy code better... but a lot of older code does not work in any case.

It looks as if you will have to keep an antique Mac around for those legacy apps. Sorry about that.

[ChessExpert]

“Apple is not responsible for the writers of BookUp’s chess programs for not upgrading their product. Apple has made every effort to make it easy to upgrade.”

Fair enough.

“It looks as if you will have to keep an antique Mac around for those legacy apps. Sorry about that.”

That’s where it stands at present.