I did a few tests on wiping compressed (Stacker) files: Sdir, the Stacker directory command, reported a 900k PKZip file had a compression ratio of 1.0:1 (no compression). I wiped the file using the same character repeatedly, and sdir reported the resultant file had a compression ratio of 15.9:1 I wiped another copy of the zip file using sets of increasing characters (0-255). After this wipe the compression ratio was 8.0:1 Lastly, I wiped the file using random characters, generated using Turboc's random() function. This time, the compression ratio was 1.0:1, the same as the original. Sounds like wiping with random characters may indeed be the way to go to avoid "slack" at the end of the file. One interesting note: When I fragmented the original zip file into 50K segments with a "chop" program, sdir reported that each segment had a compression ratio of 1.1:1, even though the original file showed no compression. When I created 10K segments, I got a compression ratio of 1.6:1 Pkzip however, was unable to compress these file segments at all. I suspect that Stacker is not really compressing these smaller files in the normal sense, but is storing them more efficiently (better sector or cluster size?). Jim Pinson