Original: Some poorly implemented game ports (usually built-in on old motherboards and I\/O cards) did n't fully support either 4 axes or 4 buttons, making only the use of a single 2-axis and 2-button joystick possible.
Simplified: Some poorly implemented game ports (usually built-in on old motherboards and I\/O cards) did not fully support either 4 axes or 4 buttons, making only the use of a single 2-axis and 2-button joystick possible.