Alice Averlong🏳️⚧️oh hello copy protection, fancy meeting you here
oh hey that's fun. this game has two layers of copy protection! if I hack the "check weird sector" code to always return 0 (for found-it), it tells me "Diskette/version out of phase"
they call the copy protection on two different sectors, and throw the out-of-phase error if they give the same result, I think
so you can't just overwrite check_copyprotection_sector with return 0
oh god they overwrite the DOS interrupt 1E in the middle, to make DOS think it's a different kind of floppy disk.
okay I now know HOW to crack the game, I just gotta write the x86 assembly.
normal people don't do this. normal people don't write 16bit DOS assembly in 2025.
I have 37 bytes. this won't be hard
and... it doesn't work.
tertiary copy protection?
tertiary copy protection?
I think they might be depending on the value of the weird sector elsewhere. like they're loading it SOMEWHERE, maybe they overwrite some code?
I need a comparative DOS CPU tracer.
Like, load two copies of the same EXE, and run until the execution diverges
THEY CHECKSUM THE FIRST 16KB OF EXECUTABLE RAM?
I patched the EXE to have the right value, but then they checksum it, and now the value is wrong!
insert pop-team-epic "you are motherfucker" here
they checksum memory MORE THAN ONCE!?
I patched out the checksumming and I think I've got it.
okay, so, the copy protection:
1. It checks for a sector that should not exist: Track 38, sector 113.
It's on a single-sided double density floppy (160kb), so there's supposed to be 8 sectors per track. But as we saw in this post:https://digipres.club/@foone/115011910054706753
this disk DOES have a sector 113.
Foone🏳️⚧️ (@[email protected])
Attached: 1 image oh hello copy protection, fancy meeting you here
Maki 🔻 🌹@foone They probably studied at the California Institute of the Arts: https://en.wikipedia.org/wiki/A113
