keirf/greaseweazle

Official SPS IPF #3158 (Kick Off 2, Atari ST) cannot be written to disk

keirf opened this issue · 4 comments

keirf commented

Problem is that the SPS IPF library returns CapsTrackInfo.overlap field as -1, which appears to mean "unknown". Since the Anco protection includes sectors crossing the index mark, we cannot correctly write them without knowing the correct write splice point.

This needs some investigation:

  • Can DTC/Kryoflux write this IPF?
  • Is there a heuristic we can use to sensibly guess a splice point?
  • Should Greaseweazle explicitly reject such IPF images with a clear error message?
keirf commented

This also applies to

  • #3159 Kick Off 2: The Final Whistle
  • #3183 Kick Off 2: Winning Tactics
  • #3215 Kick Off 2: Return to Europe
keirf commented

Looking at an original dump, compared with IPF, the original has two aspects to the NFA region missing from the IPF:

  • It is longer (but presumably the protection check doesn't care)
  • There is irregularity near the end of the NFA, which is probably a write splice.

From this I may be able to implement a heuristic to drop a write splice at the end of a NFA or fuzzy region if no splice is specified.

keirf commented

See also #231 which can probably be fixed at the same time (fixing verification of NFA regions).