Amiga MOD Packers Described - Eureka Packer Described

Format name : Eureka Packer
Created by : Eureka / Concept (1990-91)

Sources :
* Own converted musics with the packer (bugged btw ..).
* "EU.Enigma Year" sent to me by Gryzor (thx !)

OFFSET	SIZE (bytes)	COMMENT
0	14h	- Title

The following is repeated 31 times
with 30 bytes description for one sample

14h
2Ah
2Ch
2Dh
2Eh
30h

16h
2
1
1
2
2

- Sample Name
- Sample Size / 2
- Finetune (0->F)
- Volume (0->40h)
- Loop Start / 2
- Loop Size / 2

3B6h
3B7h
3B8h
438h
43Ch
-
-
-
?!?
?!?
-
-
-

1
1
80h
4
?!?
-
-
-
18h
?!?
-
-
-

- Number of pattern to play
- Noisetracker byte set to $7F
- Pattern table
- Address of the sample data
- track table. It is the address of each track for each pattern. Each value is a word. So, first pattern will be defined by the four first tracks (4 first words)
- ?!? (no clue)
- tracks datas. Refer to the track address table upward. All the files I've packed so far DO have the first track address at $850, but ...

each track is packed as follow :

* Case 1: (same as ptk with the two first bits both set to 0)

     -- Sample number ---
    /                   /\
   ||                  |  |
 0000 0000  0000 0000  0000 0000  0000 0000
 ||   |             |       |  |  |       |
 ||    \           /         \/    \     /
 ||     Note Period        effect   effect
  \                               parameter
   -- descriptions bits both set to 0

* Case 2: (only an effect with its parameter)

 0100 0000  0000 0000
 ||   \  /  \       /
 ||  effect  effect
 ||         parameter
 | \
  \ - description bit 6 set to 1
   - description bit 7 set to 0

* Case 3: (no effect nor effect parameter)

   - description bit 7 set to 1
  / - description bit 6 set to 0
 | /
 ||
 1000 0000  0000 0000  0000 0000
      |  |  |  | |             |
      four   \ |  \           /
   lower bits \|   Note Period
   of smp nbr  |
              four
           higher bits
           of smp nbr

* Case 4: (empty rows ..)

   - description bit 7 set to 1
  / - description bit 6 set to 1
 | /
 ||
 1100 0000
   |     |
    \   /
     -------- Number of empty row to bypass (-1 !)

Follow Sample datas stored like Protracker. Nothing is packed..