n.
1. obs. Once upon a time, before all-digital switches made it
possible for the phone companies to move them out of band, one could
actually hear the switching tones used to route long-distance calls. Early
phreakers built devices called blue boxes that could reproduce these tones,
which could be used to commandeer portions of the phone network. (This was
not as hard as it may sound; one early phreak acquired the sobriquet
Captain Crunch
after he proved that he could generate
switching tones with a plastic whistle pulled out of a box of Captain
Crunch cereal!) There were other colors of box with more specialized
phreaking uses; red boxes, black boxes, silver boxes, etc. There were
boxes of other
colors as well, but the blue box was the original and
archetype.
2. n. An IBM machine, especially a large (non-PC) one.