The key L is the base note of the key's scale (displayed in the bottom left)
As an example here are the keys for Cmaj:
		L 	= C
		Left 	= D
		Down 	= E
		Right 	= F
		Up 	= G
		B 	= A
		A 	= B
		R 	= C (one octave higher than L)



The Setup screen allows you to toggle the bits on
the Length/Wave Duty/Envelope Register.
Changes apply to both channels 1 and 2.

Pressing B on the setup screen enables the use of the Length.
Larger numbers mean shorter time.

For more information on the GBA's sound system check one of these sites:
 * http://nocash.emubase.de/gbatek.htm#gbasoundcontroller
 * http://www.cs.rit.edu/~tjh8300/CowBite/CowBiteSpec.htm#Sound%20Controls


	- David Shere <wolliw@sonic.net>