     trk   00     01     02   |
      ch   01     15     10   |
pat     |c-4 7f|d#4 50|--- --||
000     |--- --|--- --|--- --||
        |--- --|--- --|--- --||
size    |--- --|--- --|--- --||
064     |--- --|--- --|--- --||
        |4ax 0f|--- --|--- --||
hlstep  |--- --|--- --|--- --||
4       |--- --|--- --|--- --||
        |--- --|--- --|--- --||
        |--- --|--- --|--- --||
        |--- --|--- --|--- --||
                              |
order: 00 01 01 01 02 00 -- --|
       00 01 02 03 04 05 06 07|
  bpm: 090                    |
file: NEW LOAD SAVE           |
                              |
status: editing               |
------------------------------+

switch between status "edditing pattern", "editting order", "edit bpm", "file" ---> SELECT
	editing pattern
		switch between "pat", "size", "hlstep", "channels" and "pattern" ---> L/R (circular)
			"pat", "size" and "hlstep"
				pad UP/DOWN to increase/decrease
			"pat"
				A to add a new pattern and goto it
			"channels"
				pad LEFT/RIGHT to move across tracks. UP/DOWN to increase/decrease MIDI channel
			"pattern"
				pad UP/DOWN/LEFT/RIGHT to locate cursor
				hold A and then DOWN/UP to decrease/increase the field value
				|aab cc|
					aa := --, c-, c# ... b-, ^^  (empty, notes and note off)  RIGHT/LEFT to go directly to ^^/--
					b  := 0 ... 9, A, x  (octave, only if aa != --) "x" --> "aa" becomes a controller number
					cc := 00 ... 7f  (velocity or controller, only if aa != --)  LEFT/RIGHT to decrease/increase by 0x10
				"ch" field holding A or B and UP/DOWN to decrease/increase MIDI channel
	editing order
		pad LEFT/RIGHT to move across order table
		pad UP/DOWN to increase/decrease pattern number (--, 00, 01, 02, 03 ...)
	edit bpm
		pad LEFT/RIGHT to increase/decrease value
		pad UP/DOWN to increase/decrease value by 10
	file:
		pad LEFT/RIGHT to move across options
		A to execute option
START to start/stop playing
	from "editing pattern" status (TODO)
		from "pattern" ---> play pattern from cursor
		else ---> play entire pattern
	from "editing order" status (TODO)
		play song from order position
	else play entire song
