This file documents the file formats used in Star Control 1.

The .pkg files are in the format described in the file "pkgformat".
The extracted files are described in this document.

The following describes the format used in the DOS version of SC1.

Resource types used in starcon.pkg:
 1 - key config
 2 - some graphics type (flags = 7)
 3 - some graphics type (flags = 1)
 4 - some graphics type (flags = 2) 5 - some graphics type (flags = 3)
 6 - font
 7 - scenario
 8 - palette
 9 - strtab
10 - ? (sound?)


Files of types 2, 3, 4, 5, 9, and 10 may be compressed; they have
a header of the following format: have the following format:

Uncompressed files:
   off  len
  0x00    1  0 (means: not compressed)
  0x01    1  flags, 0 in practice
  0x04    2  Number of bytes that follow (MSB first)
  0x06       start of data

Compressed files:
   off   len
  0x00     1  6 (means: compressed)
  0x01     1  flags
              bit 0: unused
              bit 1: (table2CodeLen)
                     if not set: table2 results are shifted by 6 bits.
                     if set: table2 results are shifted by 7 bits.
                     (never set in PC SC1 files)
              bit 2: (litencoded) set if literal bytes are Huffman encoded
                     (never set in PC SC1 files)
              rest: unused
  0x02     4  uncompressed size (MSB first)
  0x06        Huffman table 0 (8-bit codes) (only present if litencoded set)
                used for encoding literal bytes
              Huffman table 1 (6-bit codes)
                used for encoding lengths
              Huffman table 2 (6-bit codes)
                used for the most significant table2CodeLen bits of an offset



Huffman table:
(numbers are in bits)
         8           one less than the number of lengths of codes
                     in the table (lenCnt)
         8 * lenCnt  LONIBBLE: one less than one of the code lengths
                     HINIBBLE: one less than the number of codes with
                               this length
This is enough to construct the huffman table.

TODO: document the rest of the compression format; for now, look at the
      code of sc1-decomp.


Resource type 1 (key config):
   off  len
  0x00    1  bottom player special key ('n')
  0x01    1  top player special key    ('1')
  0x02    1  bottom player left key    ('m')
  0x03    1  top player left key       ('2')
  0x04    1  bottom player right key   (',')
  0x05    1  top player right key      ('3')
  0x06    1  bottom player thrust key  ('.')
  0x07    1  top player thrust key     ('4')
  0x08    1  bottom player fire key    ('/')
  0x09    1  top player fire key       ('5')
  0x0a    1  ?
  0x0b    1  ?
  0x0c    1  ?
  0x0d    1  ?
  0x0e    1  ?
  0x0f    1  ?
  0x10    1  ?
  0x11    1  ?
  0x12    1  ?
  0x13    1  ?


Resource types 2, 3, 4, and 5 (graphics):
The difference between those types is the flags parameter that is passed
to the load functions (see above in the table of resource types).
bit 0: ?
bit 1: probably indicates whether a palette is used
bit 2: ?
rest: unused

(after decompression/removing packing header)
   off  len
  0x00    4  "IANM"
  0x04    2  frame count (MSB first)
  0x06    2  MSB first
             LOBYTE: bits per pixel. All SC1 files are either 1 bpp or 4 bpp.
For every frame:
          2  width (MSB first)
          2  height (MSB first)
For every frame:
          2  x hotspot
          2  y hotspot
          1  if not zero, the file includes palettes
          1  transparant color
         16  (optional) (CGA?) palette (16 entries of 1 byte)
         16  (optional) (EGA/Tandy?) palette (16 entries of 1 byte)
         16  (optional) (MCGA/VGA?) palette (16 entries of 1 byte)
          ?  pixel data (indicees in palette)



Resource type 6 (font):
   off  len
  0x00    1  ?
  0x01    1  ?
  0x02    1  LONIBBLE:
             HINIBBLE:
  0x03   48

The letters are actually readable if you do 'xxd -b'; it shouldn't be too
hard to RE this one.


Resource type 7 (scenario):
   off  len
  0x00   16     Title (\0 terminated)
  0x10    ?     Short description (\0 terminated)
     ?    ?     Unknown (probably description of star systems, Space Spines,
                fleets and bases (maybe random seeds?))
  0x80  840(?)  Long description (\0 terminated)


Resource type 8 (palette):
   off  len
     0  768  palette data:
for each of the 256 entries (with index 0 through 255):
          1  red value
          1  green value
          1  blue value


Resource type 9 (string):
   off  len
  0x00    2       Number of strings (MSB first)
  0x02    2       unknown (always 0x0000)
for each string s:
          2       len[s]: length of the string (MSB first)
for each string s:
          len[s]  String data (not '\0'-terminated)


starcon.exe:
compressed using lzexe
(http://fabrice.bellard.free.fr/lzexe.html)
Using PLINK86 to load starcon.ovl as an overlay.



The Amiga version of SC1:

Resource types used in starcon.pkg:
 1 - key config (presumed; different from the DOS version)
 2 - graphics
 3 - graphics
 4 - graphics
 5 - graphics
 6 - font
 7 - scenario (as with the DOS version)
 8 - strings as on DOS, but also other data in the same format
     (presumably including sound)

Files of types 2, 3, 4, 5, 8 may be compressed as in the DOS version.

Graphics files are in a different file format as on DOS. I haven't worked
on these files yet.


Initial version created on 2007-06-01 by Serge van den Boom.