Antony N. Lord wrote:

I have an (uncompressed) backup of a folder tree on another machine.

By mistake I began working on numerous files on the BACKUP copy.

Is there an app to do a simple comparison of the 2 folder trees to find the modified items?

Cheers, Antony.

Toast has a utility called "Compare...", Toast v6 does drag and drop.
I haven't used it though, but always remembered it in case I did something like you did;)

I'm not sure if this applies but you might also try a search of the directory(s) based on the date modified info of the files.

Good luck
Paul