Admittedly, under RT-11 trying to figure out whether DUP or PIP is performing a particular COPY function is sometimes a bit fuzzy. (Let's see, COPY can also invoke FILEX, too!) It's very useful for wiping media. Of course, with some common types of media, FORMAT/VERIFY:ONLY doesn't wipe all the blocks: for example, with RX01's and RX02's, it leaves track 0 untouched. DEC OS's don't usually store data on track 0, but still... . And RL01's and RL02's might end up with replacement blocks being untouched by the operation, too. I know that the subject of this thread is how we never mess around with confidential data, but as a tool for finding things that you might not have otherwise thought of, Bob Schor's "SNOOP" program is quite effective at finding files that used to be on a disk, even identifying entire logical disks. It's on the RT SIG tape 11S113, available by anonymous ftp from: ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-11/rt/decus… in "schor2.dsk". Bob Schor also has a program called "CLEAR" whose only purpose is to blank out unused blocks on a RT-11 disk; this is in "schor1.dsk". -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927