Snakeload
=========
  info by Luigi Di Fraia <armaeth@libero.it>

V5.0
----

Used in: "Soldier of Light" (under check), "Shinobi", "Saint Dragon", "Ninja 
Warriors", "Narc" (last two supplied by c64heaven) and probably some more.

Structure:
  This turbo loader is usually contained in a CBM file loaded at $0801 (BASIC 
  area) without an autostart.

  The following text was found in "Ninja Warriors"' CBM Data file:
    SNAKELOAD V5.0 (C) STEVE SNAKE, KML 1987. THIS IS NOT SUPPOSED TO BE 
    PROTECTED
    SO DON'T THINK YOU ARE GOOD FOR CRACKING IT !!!KYLIE RULES!
Turbo blocks:
  2 pulsewidth sets have been found so far:

                           Shinobi,Ninja Warriors Saint Dragon,Narc
        bit 0              $60                    $3F
        bit 1              $A0                    $5F
        threshold (cycles) $400 (1024)            $240 (576)
  Endianess: MSbF

  Pilot: Bit 0 pulses (x2063 = 257 bytes + 7 bits)
  Sync: a single Bit 1 pulse

  Header
  ------
  5 bytes: 65 69 6C 79 4B: "eilyK" - Identifier (read backwards: "Kylie")

  1 byte: File ID
  2 bytes: Load address (Low/High)
  2 bytes: End address (Low/High)

  Data

  1 byte: Checksum (addition of datas)

  Trailer: Bit 0 pulses, last one being usually longer.
    x2032 = #$FE bytes in "Shinobi"
    x248  = #$1F bytes in "Narc", "Saint Dragon" and "Ninja Warriors"



V5.1
----

Used in: "Final Blow", "Rodland", "SWIV" (supplied by c64heaven) "Double Dragon 
3", "Indy Heat" (supplied by Mr.Fox).

Structure:
  This turbo loader is usually contained in a CBM file loaded at $0801 (BASIC 
  area) without an autostart. 
Turbo blocks:
  Bit 0: $28
  Bit 1: $48
  Endianess: MSbF

  Pilot: Bit 0 pulses (x2055, 256 bytes + 7 bits)
  Sync: a single Bit 1 pulse

  Header
  ------

  8 bytes: Identifier, read backwards. 3 of them have been found:

    B2 B4 B2 D4 CE CF D2 C6 ("FRONT242" - Uppercase and reversed) in "Final 
    Blow", "Rod Land (Side1)" 
    85 8C 8C 85 88 83 89 8D ("MICHELLE" - Lowercase and reversed) in "S.W.I.V. 
    (Side1)" 
    C8 C3 D4 C9 D2 C4 CC C5 ("ELDRITCH" - Uppercase and reversed) in "Rod Land 
    (Side2)", "Double Dragon 3", "Indy Heat" 

  1 byte: File ID
  2 bytes: End address (High/Low)
  2 bytes: Load address (High/Low)

  Data

  1 byte: Checksum
    Its value is calculated by XORing Data bytes and adding 1 to the XOR 
    checksum AFTER a byte is stored at an address with low byte being #$FF (eg. 
    $08FF, $7DFF, etc.).


  Trailer: Bit 0 pulses (x512 = #$40 bytes).