DIN connector
A DIN connector is a type of round electronic connector. It is named for the Deutsches Institut für Normung, the German national standards regulator. DIN plugs can be used in audio systems and MIDI connections.The Mini-DIN connector is similar but smaller. Before USB connectors, keyboards and mice used mini-DIN connectors.
DIN Connector Media
Five-pin male 180° DIN connector from the keyboard of an original IBM PC. Note the unusually thick shielding skirt.
Eight-pin DIN connector for a Tandy 1000 keyboard