The FileHeaderBlock is always the first block of a Stars! data file, which always start:
10 20 4a 33 4a 33 more recognisable as "� J3J3"
PaulCr described the FileHeaderBlock on HWF: Stars files start with the following:
0-1 - Size of first block and type (16 bytes, type 8) 2-5 - J3J3 6-9 - Game ID 10-11 - Version 12-13 - Turn No 14-15 - Player No and encryption seed 16 - File Type 17 - Bit 0 (1) - Turn Submitted Bit 1 (2) - Host is using file Bit 2 (4) - Multiple turns in .m file Bit 3 (8) - Game over Bit 4 (16)- Shareware Version
The following utilities read directly from the FileHeaderBlock
StarsFileStat analyses Stars! files and shows what block types are in each of your files, and at the end there will be a note on whether your files contains blocks with any of the 6 remaining unknown ids: 11, 15, 18, 22, 25, 41.
Starstat & Starinfo
Starstat & Starinfo are otherwise identical DOS and Windows programs, respectively, that report on various aspects of the Stars! gamefiles such as the version, the presence of multiple turns in a .m file etc. Both incorrectly, but consistently, report the Stars version for v1.1a(reports 1.2a), v2.0a(2.65), 2.6i(2.81j) and 2.6JRC4(2.83) game files.