ProRunner v2 format
Created by Cosmos / Sanity (1992)
Analysed by Asle / ReDoX (asle@mygale.org)

Source :
 - "Rampage" demo by Tek
 - "Rodeo" intro by Banal Project
 - "Crash test" demo by Cryptoburners
 - various cracktro by Fairlight,Delirium,paradox ...


Offset    size (byte)    Comment
------    -----------    -------
  0           4          ID "SNT!"
  4           4          pointer to the sample data (thx gryzor :)

      ***************************************
      * the following is repeated 31 times  *
      * with 8 bytes description for 1 smp  *
******************************************************
                                                     *
 8             2         Sample Size / 2             *
 Ah            1         Finetune (0 -> F)           *
 Bh            1         Volume (0 - 40h)            *
 Ch            2         Loop Start / 2              *
 Eh            2         Loop Size / 2               *
                                                     *
******************************************************

100h           1         Number of pattern to play
101h           1         NoiseTracker restart byte
102h          80h        Pattern order table
182h          100h       ?? are those used in fact ?!?
                         might be used when playing ...
282h          80h        pointer table

 pointer table contains 64 pointers ( one word each )
pointing at the first pattern data. It starts at 0000h
and goes on adding pattern sizes. As an exemple, if
pattern 0 is 1024 bytes long and pattern 1 is 1000
bytes long, first pointer table will be 0000, second
will be 0400. the rest is filled with 0000h.
 seems unusable to me ...

302h           ?         pattern data

 we get something like

 pattern 0 :
 row 0 | voice 1 | voice 2 | voice 3 | voice 4 |
 row 1 | voice 1 | voice 2 | voice 3 | voice 4 |
 row 2 ...
 row 63| voice 1 | voice 2 | voice 3 | voice 4 |
 pattern 1 :
 ...

 the size of each pattern is variable and is between
100h and 300h bytes. One voice can be 1 or 3 bytes long.
it depends if bit 7 of first byte is set to 1. If so,
the size of this voice is 1 byte. It means there's
nothing at this line. If this bit is set to 0, the size
of this voice is 3 bytes. so we get :

 1000 0000
 |
 if this bit is set, nothing follows and this is an
empty note. it meens for PTK four bytes set to 00h.
 1100 0000
  |
 if both first bits are set to 1, it meens that
previous note IN THIS ROW will be re-used ... .

if first bit is set to 0, follows the description

  0000 0000  0000 0000  0000 0000
  ||     ||     | |  |  |       |
 -| \   /  \   /   \/    \     /
| relative sample effect  effect
|   note   number         value
|  number
|------------description bit set to 0

sample number :
  hard to get by this way of coding :( ... anyway, let's try
 tro explain it ...
  first, we agree it's coded on 5 bits.
   0 0 0 0 0   ( in the order of saving )
  I name these bit 0, bit 1, bit 2, bit 3 and bit 4 in the
 same order of saving.
  in fact, all we got to do, is to rol the whole five bits
 by one on the left.
  exemples :
   10000 will become 00001   (sample 1)
   01010 will become 10100   (sample 20)
   00010 will become 00100   (sample 4)
   etc...

relative note number: (ProTracker)

C-1 to B-1 : 856,808,762,720,678,640,604,570,538,508,480,453
C-2 to B-2 : 428,404,381,360,339,320,302,285,269,254,240,226
C-3 to B-3 : 214,202,190,180,170,160,151,143,135,127,120,113

becomes : (ProRunner v2)

C-1 to B-1 : 01,03,05,07,09,0b,0d,0f,11,13,15,17
C-2 to B-2 : 19,1b,1d,1f,21,23,25,27,29,2b,2d,2f
C-3 to B-3 : 31,33,35,37,39,3b,3d,3f,41,43,45,47



 Follows Sample datas stored like ProTracker.
Nothing is packed..