If you want an adapter that just does this, Retrofrog makes one. If you want one that's more flexible that you can get other adapters to use other systems with, Bliss-Box's Gamer Pro Advanced is the best available right now IMO, and they have one called the 4 Play Advanced which is the same but with 4 inputs. MisterAddons has one called the Reflex Adapt that is also excellent and has two inputs, but isn't in stock right now. More on reddit.com

“15 pin d-sub” does not (uniquely) identify the electrically signaling which is being carried over the connector. So it is impossible to know what you need. I realize this comes as a surprise to many people, but not every thing which uses a given connector is compatible with every other thing that uses that connector. And the d-sub connectors have been around long enough to have accumulated all sorts of weird uses. More on reddit.com

Just plug a data cable in from your PSU (power supply) into it. More on reddit.com

First forget gameport to USB adpapter, this is old hardware (2000), with low resolution (8 bits) and limit stick to 6/8 buttons. Waste of money. FighterStick is easy to modernize - with option costing only $10/15: Need new USB controller, e.g. BU0836A, DSD 12 or Arduino PRO Micro ($6) + MMjoy2 firmware (free), and >1.8m USB cable. Need add - solder, one wire in each pot (potentiometer) pin - gameport wiring have wire only in 2 pins per pot. Connect your new USB controller "buttons matrix" pins with the connector that come from grip - you don't need change nothing in grip, but if want can add a 2nd stage in trigger, what require extra wiring. Follow the color of columns and rows (lines) is scheme: https://i.imgur.com/MJvEI4L.jpg https://forums.eagle.ru/showthread.php?p=3296046 BTW - Before start you need understand the "buttons matrix" - colluns x rows concept, used in joysticks buttons. Alternative option: donate this stick for Goodwill. :) More on reddit.com