Ask Max: Problems using files moved between OS 9 and OS X
Searched thru your answers, very informative but didn't find my situation. I use USB drives to move files around and they have worked well up until recently - when I started plugging them into OSX machines. When I go from my older iBook (9.2) to my Mac mini (OS X) some files - notably Appleworks files - show up as some kind of system files and can't be opened on the Mac mini - even from within Appleworks. If I use my LaCie USB drive, they do show up and transfer OK. I run Appleworks in Classic Mode on the Mac mini. There are other file types that do this as well. Am I missing something about file naming/extensions? I have thought maybe I should convert to DMG for the transfer but I'd like to keep things simple - like in the good old days.
I think you were right to suspect that the file extension is at the root of your problem. The change to using filename extensions in OS X created some controversy among Mac users because extensions aren't needed in OS 9. We have seen many great things out of OS X, but one tradeoff is that we now need to think about filename extensions. For Appleworks files it should be the same as the old ClarisWorks extension: ....CWK. So when you're saving files from OS 9 applications, make sure to include the file extension. One nice use of filename extensions is that you can easily change what application is associated with that extension in OS X. Hold down the "Option" key and click on a file and select "Get Info" from the pop-out menu. Use the "Open with:" section to change the default application and then click on the Change All button. Now, for example, all your .cwk files will open in Appleworks.
Using filename extensions and telling OS X what application the extension is for should fix your problem. Good luck