Wanted: SIMH VAX VMS tape image tester, take 2

There is always an off chance that some of the software that uses those files may expect a fixed length, and will freak out if the length isn't what it had expected. Other software may read and process records until it reaches what it thinks of as EOF. If it looks at physical EOF, it will end up reading an extraneous record, that may be of wrong size, but certainly wrong format. Remember what scanf() does when if encounters data that it doesn't understand. Not all software will exit gracefully when it encounters unexpected extraneous content after the last of the expected data. Therefore, there is some risk involved in appending anything to the file(s). Could you create a separate file that is associated with each file? filename.DAT and filename.INF That way, the .DAT file can be an "UNCORRUPTED" exact image of the original data. filename.INF could be a simple text description, maybe even in complete sentences, containing whatever is known about the file, such as record structure(s), etc. (and editable if/when more is learned!) If there is an expectation of an extreme quantity of data files, then the .INF file should have a fixed machine parseable format, followed by a freeform text component at its end. Maybe even create additional files, such as filename.JPG containing an image of the label. The big problem with that is the requirement that the .INF file stay in proximity to the file containing the image of the data. Maybe STAPLE them together?