For those completely oblivious to this: This was actually not about getting data written to disk, but to physically protect the drive from its own mechanical construction. The "park" command would cause the harddrive to move its magnetic read and write-heads away from the internal platters, so that when it was powered down and the disks stopped spinning, the platters would not be damaged or experience needless tear and wear.

Yeah, I'm glad we no longer have to do that exercise.

(This used to be how you'd tell the tape-spooler to rewind..)

Always, always sync -r after writing to a zip drive on Windows. Even minutes after you think it is finished writing, do not trust the OS to have finished flushing to disk.