:locked and loaded: [from military slang for an M-16 rifle with
magazine inserted and prepared for firing] adj. Said of a removable
disk volume properly prepared for use --- that is, locked into the
drive and with the heads loaded. Ironically, because their heads
are `loaded' whenever the power is up, this description is never
used of {{Winchester}} drives (which are named after a rifle).
-- The AI Hackers Dictionary