15 Pin Serial Cable?

Solution 1:

Hard to tell without a pic, but I'd guess its a 'DB Connector' or 'Game Port' connector.

DB-15 (DA-15 and DE-15)
Two DB-15 connectors are widely used. The larger, two-row female DA-15 is the game port on a PC, and the smaller, three-row, female high-density DE-15 is the VGA port.

The Game Port was used for joysticks, midi devices and other peripherals.

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