@mitu Thanks. Unfortunately, jstest gives me yet a third set of inputs different both from what event_diag and the other program told me. IT shows for my old fat PS3 controller:
(Axes): X, Y, Z, Rx, Ry, Rz
(Buttons): BtnA, BtnB, BtnX, BtnY, BtnL, BtnR, BtnL2, BtnR2, BtnSelect, BtnStart, BtnThumbL, BtnThumbR, null, null, null, null
It's anyone's guess which of those axes the dpad uses, and how the hackfile would interpret it, since even the latest event_diag still shows nothing for anything except the analog sticks...
I'm thinking event_diag just has trouble reading from these types of controllers, since it reads my arcade joystick and button sets, and my buffalo controller buttons, just fine.