I'm one of those old-timers who still has 'sync;sync;sync' in muscle memory, and I also remember why we did it way back in the day - in my case, I learned it during days of development on MIPS Risc/OS, and what three rapid syncs in succession did, was, tell the TAPE driver to rewind the tape.

Mass-storage back then was often done with tape decks, which were a lot cheaper than hard disks, and the triple-sync trick was a common firmware trick that tape-drive vendors used to get a cheap 'rewind command' out there for their users, without requiring platform-specific bins for the job.

Ah, that's interesting to know. Was the development system also RISC/OS, or did some UNIX variant do this as well? I thought in UNIX, tape was always used with utilities such as tar, not mounted as a part of filesystem. That should of course be possible, for the patient at least :).

It was definitely possible, and some of us remember the joys of spooling data from tape before we could use it. :)

And if I recall, this was a built-in of the tape-drive itself, which could be used on multiple different systems, and so the triple-sync being used to rewind wasn't Risc/OS specific; I remember using the same tape-deck later on Linux and Irix machines, same ol' sync command worked every time.

I can still hear the whirr in my mind ..