OK, one hurdle down. I didn't understand that XYvDosMac app has to be dragged to follow xattr -rc(space) in Terminal and THEN run the command.
xattr works on a filename, and dragging XyvDosMac there provides the filename.
I was running the command by itself, hence the error messages.
Now I need some guidance on getting XYvDosMac to load my working XY directory as default. When the initial options-setting screen came up, I tried to add my XY folder as drive A:, but instead it opens a B: with a sparkling new XyWrite installation. The text is gray on blue, not my usual white on blue, but presumably that would change with my own startup and settings files.
I know to hold down Option while loading VDos to get the options screen back, but how do I point it toward my own XY directory?
Thanks.
Jon Pareles