DB15 Pin Gameport Microphone Pre-Amp Amplifier Booster for High Impedance Mic

I found this when cleaning out a box of vintage computer parts. I believe it came with my 486sx PC which had a Microsoft Windows Sound System sound card installed. I remember needing to use this device in the 15-pin gameport port to connect my microphone to the 3.5mm female input jack, and then connect the 3.5mm male output into the microphone jack on the soundcard before the mic would work. I am guessing this was because that old microphone needed a bit of amplification to bring it up to line level, and this adapter would tap the gameport to get the power to do so.

Please let me know if you have any additional questions and I will try to answer them.