How to calibrate xbox 360 controller

I'm still interested in the real answer to this question, but in the end, I just found a controller that works.

For anyone else who really wants to do this, keep trying different controllers until you find one that works. I recommend quality console controllers (gamecube, PS2, xbox) if you already have them, connected using USB adapters, or cheap USB gamepads from eBay.

The one that worked for me cost about $7 (bought from wholesaler xinga.com years ago but try ebay etc). It's a semi-transparent (purple) chinese knock-off of the standard PlayStation 2 dualshock controller. Windows recognises it as "PS converter", so the electronics are probably identical to USB PlayStation 2 controller adapters sold by the same company (and many/most other companies, probably).

The N64 analog stick is extremely unusual. It does not use potentiometers, as most other platforms (i.e. playstation controller), but instead used a geared-up digital incremental rotary encoders.

^{This is also why you have to have the control stick centered when the system turns on. Since the stick mechanism has no concept of "centered", the N64 assumes that whatever position the control stick is in when the system is turned on is "center".}

As the gearing wore down, the play of the controller progressively increased.

Wikipedia:

The N64 Analog stick does not use analog potentiometers. It uses light emitting diodes and photo detectors controlled by sensor wheels. The sensor wheels are plastic hubs which produce a shutter effect allowing for an accurate direct digital read. The sensor wheels give direct correlation to the stick position compared to potentiometers which can change resistance values over time. However gameplay function of the stick itself is not on or off digital, but analog in a sense, the more the stick is pushed the faster a game character would walk to run.

The analog stick was prone to some long-term reliability issues. If used excessively, the stick became "loose", which means it will not fully return to center position, which may render gameplay more difficult by giving unintended, non-user input to the system. This loosening can be caused by rotating it intensively - a common practice in games like Mario Party where it offers an advantage for some mini-games.