"As an aside, for anyone interested in helping reverse engineer things: It's possible to get Windows to dump everything it sends on what it calls SPB - basicall

"As an aside, for anyone interested in helping reverse engineer things: It's possible to get Windows to dump everything it sends on what it calls SPB - basically SPI & I2C. Open the Event Viewer and enable View -> Show Analytic and Debug Logs. Then head to Application and Services Logs -> Microsoft -> Windows -> SPB-ClassExtension. Right click on Analytic and enable it - all events will be logged. Disable it when done, and look for the 1023 events, and view the details tab - they'll give you the full buffer contents. Other events will let you know things like the direction of the transfer, etc."