Okay, I stand corrected, as I found out while trying to get SETI working on an ancient Mac (PowerMac 7100).
Remove the "SETI@home Data" folder alias from the Preferences (MacOS¾8.1) or Application Support (MacOS 9+) folder. (I don't know which it is in for OS 8.5, 8.51, or 8.6.) Put the original "SETI@homa Data" folder there instead. Launch SETI@home. As soon as it starts "Baseline Smoothing", quit SETI@home. Copy the "SETI@home Data" folder to the RAM Disk. Trash the "SETI@home Data" folder from Preferences/Application Support. Make an alias of "SETI@home Data" and put it in Preferences/Application Support.
That's how I got by the "Error Creating Data directory: -48" message to stop. The above is still useful for other reasons.
[This message has been edited by Danometer (edited 10-26-2000).]