mupen64plus plugin that uses the direct controller access feature
offered by raphnet's N64 to USB adapters to let the emulated game
communicate with the controllers directly.

Advantages:
  * No calibration required. As the game talks to the controller
    directly, it reads exactly the same axis values it would in a
    non-emulated setup. In other words, the controller works, responds
    and feels exactly as it would in real life.
  * Low latency. When the game must read the controller, the request is
    forwarded directly to the controller by the adapter. The later
    immediately returns the controller's answer to the game.
  * Expansion accessory support without emulator configuration. Insert
    the accessory and you're good to go!

Supported accessories:
  * Rumble pak
  * Controller pak (Memory pak)[1]
  * Transfer pak[1]
  * Bio sensor

Support for peripherals other than controllers.
  * N64 mouse (tested)
  * VRU (confirmed by users, requires special ports1_4 version of the
    plugin)[1]
  * N64 Keyboard (not confirmed)

Supported adapters:
  * N64 to USB adapter - V3
  * Dual N64 controller to USB adapter
  * N64/Gamecube to USB adapter - V3

[1] When accessories transfer a lot of data, such as a Controller Pak,
    Transfer Pak or VRU, there are audio issues (small pauses) and
    temporary game slow downs.