twirling baton

n. [PLATO] The overstrike sequence -/|\-/|\- which produces an animated
twirling baton. If you output it with a single backspace between characters,
the baton spins in place. If you output the sequence BS SP between
characters, the baton spins from left to right. If you output BS SP BS BS
between characters, the baton spins from right to left. This is also
occasionally called a twiddle prompt. The twirling baton was a popular
component of animated signature files on the pioneering PLATO educational
timesharing system. The archie Internet service is perhaps the best-known
baton program today; it uses the twirling baton as an idler indicating that
the program is working on a query. The twirling baton is also used as a boot
progress indicator on several BSD variants of Unix; if it stops, you're
probably going to have a long and trying day.

