Dictionary.net

(IBM called this a "chip box") A metal box aboutthe size of a lunchbox (or in some models a largewastebasket), for collecting the chad that accumulated inIron Age card punches. You had to open the covers of thecard punch periodically and empty the chad box.The bit bucket was notionally the equivalent device in theCPU enclosure, which was typically across the room inanother great grey-and-blue box.