I have a usb n64 controller adapter and I don't know how to calibrate it. I ran jscal and everything but the joystick portion still only registers half way. and when I do try to calibrate it, It thinks it has 12 axises!
I know this is an old post but I recently figured out how to do this myself after much searching, trial and error, etc.
I wrote a detailed tutorial which I posted on my blog.
Feel free to distribute!