MPS_Format.txt

MicroProse Music Format
=======================
used by Transport Tycoon

There are two variants: an AdLib and a MIDI version. There are minor differences between them.

General Layout (MIDI)
--------------
1 byte - Tempo (BPM)
1 byte - macro count
?? bytes - macros
1 byte - track count
?? bytes - tracks

General Layout (AdLib)
--------------
1 byte - Tempo (BPM)
1 byte - number of instruments ni
18h*ni bytes - FM instrument data
	register order: 20 23 40 43 60 63 80 83 E0 E3 C0 [+ 0Dh unused bytes]
1 byte - macro count
?? bytes - macros
1 byte - track count
?? bytes - tracks

Macro
-----
4 bytes - size of data (includes this value) nn
n-4 bytes - macro data

Track (MIDI)
-----
1 byte - channel ID
4 bytes - size of data (includes this value) nn
n-4 bytes - track data

Track (AdLib)
-----
4 bytes - size of data (includes this value) nn
1 byte - channel ID
n-5 bytes - track data

Commands are the same as with MIDI, except:

Track Data
----------
The structure is similar to MIDI:
  [delay] [command] [delay] [command] ...

Commands are MIDI-like and include "running status" support.

80 nn vv - Note Off, note nn, velocity vv
90 nn vv - Note On/Off, note nn, velocity vv
B0 cc vv - Control Change cc, value vv
C0 vv - Patch Change, value vv
	Note: value 7Eh is used as a loop marker and is not sent.
E0 ll mm - [MIDI] Pitch Bend, value mmll (raw MIDI value)
E0 vv - [AdLib] Pitch Bend, value vv
	00h = 1 semitone down, 10h = centre, 20h = 1 semitone up
FD - Macro End
FE ii - call Macro ii
FF 2F - Track End
	Note: The driver only checks for the "FF" byte.