Last Ninja 2 disk-transfer protection

Having had some time to analyse the disk-transfer protection code in LN2, I can confirm it is similar to the one I saw in LN: In both cases the image registers of CIA 2 timers are used.

What this means is that if the game is not loaded from tape, the protection kicks in:

  • For LN the game just hangs when Armakuni is hit.
  • For LN2 all Integrator data pointers are intentionally corrupted when Armakuni picks up any object. After that the game attempts to use garbage data for graphic operations and things go horribly wrong: to an inexperienced cracker this condition might appear like the crack itself might be missing some required data file from tape or some data files might have been improperly transferred to disk.
This entry was posted in Retrocomputing, Technical and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s