When you save a form in the Screen Editor or a source file in the Source Code Editor the current file, if any, is copied automatically to a backup file. This will preserve the last form or source file prior to the current changes. The form (normally with the extension of .DFM) is copied to the same name with the extension of .BFM. The source file, normally with the extension of .SRC, is copied to the same name with the extension of .BAK.
Note : There is no backup procedure when using the program manager at this time. We may be adding a backup feature in the program manager in future version of TAS Professional powered by CAS.