jakebox chip in box

Originally, the bit bucket was the container on Teletype machines or IBM key punchmachines into which chad from the paper tape punch or card punch was deposited;^[3]the formal name is "chad box" or (at IBM) "chip box".

The term was then generalized into any place where useless bits go. In Unix and Unix-like operating systems, this term is used to refer to /dev/null. On HP OpenVMS, this term refers to device "NLA0:" ("NL:" may also be used). On UNIVAC Series 90operating systems such as VS/9, it referred to "*DUMMY". On the DEC PDP-11, the bit bucket is "NL:". On DOS and Windows CMD, it is the "NUL" device, or simply "$null" inPowerShell.

The bit bucket is also used in discussions of bit shift operations.^[4] When the width of a given binary number is fixed, one or more bits are lost when performing a simple shift. These bits are said to have "fallen off" or to have "fallen into the bit bucket". Some CPUs move the last bit shifted off the end of a number during a shift into thecarry flag during some or all shift operations; since the bit bucket is usually considered the place where discarded (and therefore lost) bits go, the carry flag in this case would probably be excluded from the bit bucket—unless, perhaps, the speaker intended to ignore the bit saved in the carry flag and treat it as though it had been truly discarded.

Such a device is sometimes referred to as a "write once read never" or WORN device (named after the magneto-opticalWORM devices used during the 80s), and was indeed implemented as such as an Easter egg in early versions of Atari BASIC.

The WORN device is related to the First In Never Out stack and Write Only Memory, in a joke datasheet issued by Signetics in 1972.

In programming languages the term is used to denote a bitstream which does not consume any computer resources such asCPU or memory, by discarding any data "written" to it. In .NET Framework-based languages, it is the System.IO.Stream.Null.