Since the early 1990s , when the game port moved from dedicated expansion cards to PC I/O or sound cards , these connectors have usually doubled as connectors for MIDI instruments ; two of the redundant +5 V and GND pins of the original standard were rededicated to MIDI input and output to make this possible .
Since the game port moved from dedicated expansion cards to sound cards about 1990 , these connectors usually double as connectors for MIDI instruments ; two of the redundant +5 V and GND pins of the original standard were rededicated to MIDI input and output to make this possible .