In the News regarding firmware 9.1.0, I included a link to the latest version of the user manual. However, this manual contains a section on page 11 entitled "PCB Fixes" which contains an error that could cause a short circuit in your Atari Eiffel, or even your Atari Mega-ST, and in the worst-case scenario, cause a fire.
Do not follow the instructions for these PCB patches!
The correct version of the PCB patch prior to version 1.4.0 is as follows:
On the bad version, contrary to what the text indicates, the diagram showed how to connect the 5V of the Pico to the pin 8 of Joy1 instead of the pin 7.
The user manual has been updated; you can download the correct version here: Atari_Eiffel_Pico_USB-User_manual.pdf