This is still a work in progress! The code's not ready. In fact I haven't even written any code.
The original RunCPM project I did used two feathers with RP2040 microcontrollers: one for DVI output and one for USB input.
Now, with the USB Host Featherwing, there's theoretically no need for the second microcontroller.
The Adalogger Featherwing and the USB Host Featherwing need to have separate CS (Chip Select) pins.
For this project, I modified the USB Host Featherwing. I cut the small trace next to the pad labeled "CS", then soldered in a small jumper wire from CS to GPIO11, the spot just above the one labeled "GPX".
Next, it was time to update the Arduino sketch to use the USB Host Featherwing. Sadly, it appears that this is incompatible with the Philhower core at this time, so the project is on hold.