maps files format:
------------------

 Note: Datas are big endian.

   0.l: "T7MP"
   4.l: Size of the chunk (4)
   8.l: File size

  12.l: "XBLK"
  16.l: Size of the chunk (4)
  20.l: Horizontal size of the map (all levels have the same size)

  24.l: "YBLK"
  28.l: Size of the chunk (4)
  32.l: Vertical size of the map (all levels have the same size)

  36.l: "VERS"
  40.l: Size of the chunk (0x1c/28)
  44.l: ??? (Filled with 0s)

  72.l: "COM1"
  76.l: Size of the chunk (0x1c/28)
  80.l: ??? (Filled with 0s)

 108.l: "COM1"
 112.l: Size of the chunk (0x1c/28)
 118.l: ??? (Filled with 0s)

 144.l: "REMX"
 148.l: Size of the chunk (4)
 152.l: Maybe the last X position used in the editor before saving the map

 156.l: "REMY"
 160.l: Size of the chunk (4)
 164.l: Maybe the last Y position used in the editor before saving the map

 168.l: "IFFP"
 172.l: Size of the chunk (0x40/64)
 176.b: Filename of the background tiles picture used (only chars from 13 to 16 are used)

 240.l: "PALA"
 244.l: Size of the chunk (0xc0/192)
 176.b: Filename of the palette (64 bytes) (probably stored in a CAMG IFF chunk for the editor)
 312.w: Datas of the palette (128 bytes only 64 used) (used by the game)

 440.l: "PALB"
 444.l: Size of the chunk (0xc0/192)
 448.b: Filename of the palette (64 bytes) (probably stored in a CAMG IFF chunk for the editor)
 512.w: Datas of the palette (128 bytes only 64 used) (used by the game when the timer is on)

 640.l: "PALC"
 644.l: Size of the chunk (0xc0/192)
 648.w: Not used
 712.w: Not used

 840.l: "PALD"
 844.l: Size of the chunk (0xc0/192)
 848.w: Not used
 912.w: Not used

 1040.l: "COLS"
 1044.l: Size of the chunk (4)
 1048.l: ??? (0 or 1) (not used in the game)

 1052.l: "CCCL"
 1056.l: Size of the chunk (0x40/64)
 1060.b: A series of bytes (not used in the game)
     
 1124.l: "IFFC"
 1128.l: Size of the chunk (0x800/2048)
 1060.b: A series of bytes (not used in the game)
     
 3180.l: "BODY"
 3184.l: Size of the chunk (0x5a00/23040) (XBLK*YBLK*2)
 3188.w: tiles datas

     Bits  0-5: Attribute of the tile:

                0x00: floor
                0x01: wall
                0x02: exit
                0x03: door
                0x04: key
                0x05: first aid
                0x06: ammo
                0x07: 1 up
                0x08: fire door left button
                0x09: fire door right button
                0x0a: small face huggers hatch.
                0x0b: 100 credits
                0x0c: 1000 credits
                0x0d: normal floor but with tiles using metallic grid
                      (maybe it was meant to use some different footsteps sound
                       when the players are stepping on them ?)
                0x0e: one way (players lose health when reaching this tile from below)

                          up 
                          /\
                          /\
                         down

                0x0f: one way (players lose health when reaching this tile from the left)

                     left >> right

                0x10: one way (players lose health when reaching this tile from above)

                          up 
                          \/
                          \/
                         down

                0x11: one way (players lose health when reaching this tile from the right)

                     left << right

                0x12: fire door left button
                0x13: fire door right button
                0x14: deadly hole
                0x15: evil 1 up (initiate immediate level destruction sequence if touched)
                      also main reactor (same effect except there's time to flee)
                      also some walls in level 11
                0x16: acid pool (only used in level 5)
                0x17: intex terminal
                0x18: ship reactor up 1 (2x2 tiles)
                      white force field (2x2 tiles)
                      ventilation (2x2 tiles)
                      arms walls (tongues ?) in level 12 (1x4 tiles)
                0x19: ship reactor up 2 (2x2 tiles)
                      white force field (2x2 tiles)
                0x1a: ship reactor up 3 (2x2 tiles)
                      opening/closing hatch (2x2 tiles)
                      part of pulsating ball in level 12 (5x1 tiles)
                0x1b: ship reactor down 1 (2x2 tiles)
                      vertical running engine (2x2 tiles)
                      vertical red force field (1x3 tiles)
                0x1c: ship reactor down 2 (2x2 tiles)
                0x1d: ship reactor down 3 (2x2 tiles)
                      vertical wall flashing light (1 tile)
                0x1e: horizontal red force field (4x1 tiles)
                0x1f: ventilation (2x2 tiles)
                0x20: not used in the game
                0x21: not used in the game
                0x22: not used in the game
                0x23: not used in the game
                0x26: one way (deadly)

                     left >> right

                0x27: climb

                     left floor << right floor

                0x28: respawning location of big aliens
                0x29: respawning location of small aliens
                0x2a: power dome 1
                0x2b: power dome 2
                0x2c: power dome 3
                0x2d: power dome 4
                0x2e: one way (deadly)

                     left << right

                0x2f: climb

                     left floor >> right floor

                0x30: not used in the game
                0x31: not used in the game
                0x32: not used in the game
                0x33: trigger vertical force fields sequence when fighting reactor boss.
                0x34: hole with aliens coming out
                0x35: players starting position
                0x36: used in level 12 for the last boss,
                      the game throws a random number and the tile have 37,5% chance of making the boss to stop
                      otherwise, no effect.
                0x37: climb

                        up floor
                           /\
                           /\
                       down floor

                0x38: one way (players lose health when reaching this tile from below / left)

                           up
                           /\
                      left >> right
                           /\
                          down

                0x39: one way (players lose health when reaching this tile from above / left)

                            up
                            \/
                       left >> right
                            \/
                           down

                 0x3a: one way (players lose health when reaching this tile from above / right)

                            up
                            \/
                       left << right
                            \/
                           down

                0x3b: one way (players lose health when reaching this tile from below / right)

                            up
                            /\
                       left << right
                            /\
                           down

                0x3c: not used in the game
                0x3d: boss trigger
                0x3e: not used in the game
                0x3f: climb

                        down floor
                            \/
                            \/
                         up floor
          
     Bits 6-15: Index of the tile gfx (*16 to obtain gfx offset in the background picture).
