G-Tech MIDI MPU Format
=-=-=-=-=-=-=-=-=-=-=-

This format is used by Richy2000 in his MIDI Lib MPU. 
It Plays MIDI using the MPU-401 interface, and maybe MPU-404 
inteface too someday. The file format will be similar to that of a MOD.

Header:

ID:        4 Bytes  -  "GmID"   - Identifys that its a G-Tech MIDI MPU
Type:      Word                 - What Type of GMD, used to add extras
Tracks:    Word                 - To you MOD Music Makers, Patterns
Tempo:     1 Byte               - Speed in Hz
Sequence:  256 Bytes            - Order to play Tracks/Patterns, max = 128

Now starts the Tracks, 64 Notes in length, with 16 Channels on each Row.

Track Header:
ID:        4 Bytes   - "TmID"   - Tells you that this is the start of a track
Commands:  48 Bytes             - 2 Bytes for each note, explained later. Repeated
                                  64 times each track.

The Commands for each track in the command chunk are very simple:

Byte 1 - The Command Itself
Byte 2 - The Data
Byte 3 - The Channel Instrument. If 255 it isn't effective.
Byte.........

You get the idea. There are 48 Bytes, for all 16 Channels. Now for the commands:

Hex	Purpose
====================
0A	Skip Track
0B	Note On
0C	Note Off
0D	Pitch Bend (V2)
0E	Reserved (V2?)
0F	Change Instrument
1x	Play Note with Specific Volume (x)