Power Music format
Created by Joakim Ogren
Analysed by Asle / ReDoX (asle@mygale.org)

Source:
 - one !PM! packed file sent by Gryzor (thx !)


Offset    size (byte)    Comment
------    -----------    -------
  0          20 14h      Title

      ***************************************
      * the following is repeated 31 times  *
      * with 30 bytes description for 1 smp *
******************************************************
                                                     *
 20           22         Sample Name                 *
(14h)        (16h)                                   *
 42            2         Sample Size / 2             *
(2Ah)                                                *
 44            1         Finetune (0 -> F)           *
(2Ch)                                                *
 45            1         Volume (0 - 40h)            *
(2Dh)                                                *
 46            2         Loop Start / 2              *
(2Eh)                                                *
 48            2         Loop Size / 2               *
(30h)                                                *
                                                     *
******************************************************

950            1         Number of pattern to play
(3B6h)
951            1         noisetracker byte (FFh)
(3B7h)
952           128        pattern table
(3B8h)       (80h)

1080           4         "!PM!"  ID string
(438h)
1084           ?         Pattern datas. Same storing as ptk.
(43Ch)


 each pattern takes 400h bytes
 row 00 | channel 1 | channel 2 | channel 3 | channel 4 |
 row 01 | channel 1 | channel 2 | channel 3 | channel 4 |
  ...
 row 63 | channel 1 | channel 2 | channel 3 | channel 4 |

 each note is coded that way :

   ----Sample number-----
  /  /                \  \
 |  |                  |  |
 0000 0000  0000 0000  0000 0000  0000 0000
      |             |       \  /  \       /
       \           /       effect  effect
        -Note value               parameter
                   


 Follows Sample datas ... use the following formula to
retrieve the original samples :

|------------------------------------------------------|
|  NewSample[0] = OldSample[0]                         |
|  cpt=0                                               |
|                                                      |
|Loop_Point:                                           |
|  NewSample[cpt] = NewSample[cpt-1] + OldSample[cpt]  |
|  cpt = cpt + 1;                                      |
|  goto Loop_Point                                     |
|------------------------------------------------------|

 There, and just dont forget to use SIGNED CHARS !!!!.