---snip--- No, that is not true. The description of the physical data in the archive should be sufficient to recover the system side data. I can state this because the system side data is just a subset of the physical data. I recommend that the archive should include enough information to translate from the physical to the system but for archiving purposes, that is not absolutely necessary. It is not that hard to describe as part of the header what FM looks like. Still, if we restrict all archived information to include this, some unknown formats may not be archived because the person with the data doesn't know that format. It is better to capture the data first. It may also be that the only way that person has to capture the data is the output of a controller chip. The archiving should allow this as well ( more in the format the Steve would like it all to be in ). This file could later be combined with the more physical information when that was available, just as a archive file that originally had only physical information could be appended with the data as seen by the system. What this means is that some of the archived files may not be directly useable by Steve and his tools without some more in depth knowledge about the encoding use. It doesn't make it impossible to use, just difficult. Dwight