Well, you will need create and code for Arduino or other USB board for make this external converter, like Real Simulador did for Cougar TQS, their TUSBA Adapter.
Similar to these adapters - that still available, released around 2000, when joysticks migrated from gameport to USB, that limited axes to only 8 bits (256 points) and recognize up to 6/8 buttons.
Probable the best reference about an DIY gameport>USB adapter is the old 3DVERT for use Microsoft Force Feedback PRO (gameport) in USB port.
https://www.descentbb.net/viewtopic.php?t=7090What require manufacture an PCB and solder components:
Similar:
https://dicks.home.xs4all.nl/avr/usbtiny/An option that is more complicated, laborious, costly, subject to errors than just get a couple of cheap (~$6) Arduino PRO Micro, flash MMJoy2* firmware (job similar to record a file in DVD), just solder* 2 new wires inside F22PRO joystick and redo all wiring inside F-16 TQS.
* Just one option, are others code for Arduino around. I suggest MMJoy2 because:
- Was based on MJoy8/16 (2004) DIY USB controller - build by hundreds of simmers (I build a half dozen) and used today in GVL224 and Kanttorini throttles, in the past by BRD controls.
- MMjoy code was developed by MegaMOZG, the same guy that after create VirPil/VPC electronics.
- Was used by hundreds of DIY simmers.
**As you see, all options require make solders.
Don't know if still in business, but this guy have developed an more ready to use option:
http://www.spec-tech-dmt.com/products.htmlAnyway pictures serves as example of what you need do if opt by DIY way.