I recently acquired a Logitech Wingman Formula Force from a thrift store. This controller is marketed as USB or serial port.

By default the controller ships with a native serial connector, but then could be converted to USB using what appeared to be a converter. I am missing that converter.

Due to the fact it claims to have native USB I decided to open it up. Inside I found it has a ADM232AARW Serial Controller as well as a Intel N80930AD4 USB Controller.

The presence of both chips has lead me to the possibility that the supplied converter was not a serial bus to USB converter but instead just converted the connector to work as a USB.

What would be the best way to test to see if my suspicions are correct and how would I be able to figure out the correct pin-outs used to make the conversion?


Here is the board.

enter image description here

Based on a comment below I used a multimeter to track back the pinouts from the smaller connector to the bigger connector. Additionally I tried to get back to the USB controller but was only able to find trace back the connector to D p0, D m0, and V ccp.

With these three connections is it possible to create a crossover cable to USB?

Is it also possible to safely test without risking damage to either connecting device?

  • \$\begingroup\$ I would simply use a DMM in resistance measurement mode to find out which pins of the connector are connected to DP0/DM0 of the USB controller. Most likely with a resistance in the 20Ω range. \$\endgroup\$ – Janka Oct 20 '16 at 23:46
  • \$\begingroup\$ A photo of the board would be enough really. \$\endgroup\$ – Passerby Oct 21 '16 at 1:06
  • \$\begingroup\$ @Janka I was able to find DP0, DM0, and VSSP. Is it possible to make a crossover cable at this point? \$\endgroup\$ – Daniel Oct 21 '16 at 2:50
  • \$\begingroup\$ Crossover cable? What does that mean? I'm pretty sure the RS232 channel connects to TxD (pin 21) and RxD (pin 20) while the USB connects to DP0 (pin 55) and DM0 (pin 54). They don't share the same pins on the connector because of the different voltage levels. \$\endgroup\$ – Janka Oct 21 '16 at 7:35
  • \$\begingroup\$ @Daniel Indeed, if you were able to find where DP0, DM0, VSSP are on the connector, you are on the right track. Try to find the 5V VBUS, and you should be able to make a simple direct cable that will hopefully work. The Intel USB controller chip seems to be powered with 5V directly, so maybe its VCC supply (pins 36,68) and VCCP (pins 19,51) are directly connected to the USB VBUS somewhere on the connector (or eventually through some small ferrite). \$\endgroup\$ – dim Oct 21 '16 at 9:09

This article from 2008 gives the following diagram:

Logitech combo adapter


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