IBM XT 5160 Technical Reference page 380

tracks of a disk storage device that can be accessed without
repositioning the access mechanism.
daisy-chained cable. A type of cable that has two or more
connectors attached in series.
data. (1) A representation of facts, concepts, or instructions in a
formalized manner suitable for communication, interpretation, or
processing by human or automatic means. (2) Any
representations, such as characters or analog quantities, to which
meaning is, or might be· assigned.
data base. A collection of data that can be immediately accessed
and operated upon by a data processing system for a specific
purpose.
data processing system. A system that performs input, processing,
storage, output, and control functions to accomplish a sequence
of operations on data.
data transmission. Synonym for transmission.
dB. Decibel.
dBa. Adjusted decibels.
dc. Direct current.
debounce. (1) An electronic means of overcoming the
make/break bounce of switches to obtain one smooth change of
signal level. (2) The elimination of undesired signal variations
caused by mechanically generated signals from contacts.
decibel. (1) A unit that expresses the ratio of two power levels
on a logarithmic scale. (2) A unit for measuring relative power.
decoupling capacitor. A capacitor that provides a low impedance
path to ground to prevent common coupling between circuits.
Deutsche Industrie Norm (DIN). (1) German Industrial Norm.
(2) The committee that sets German dimension standards.
digit. (1) A graphic character that represents an integer; for
example, one of the characters 0 to 9. (2) A symbol that
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