The original game port design by IBM ( released in 1981 as a separate expansion card for the first IBM PC ) initially allowed four analog axes and four buttons on one port , allowing two joysticks or four paddles to be connected , although this required a special `` Y-splitter '' cable and is not fully supported by some combined midi\/game ports usually found on sound cards .
The original game port design by IBM ( released in 1981 as a separate expansion card for the first IBM PC ) initially allowed four analog axes and four buttons on one port , allowing two joysticks or four paddles to be connected , although this required a special `` Y-splitter '' cable and is n't fully supported by some combined midi\/game ports usually found on sound cards .