Ultima II for Apple II protection scheme

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Dominus
Posts: 59
Joined: Tue Mar 01, 2016 10:32 am

Ultima II for Apple II protection scheme

Post by Dominus »

Don't know if it is the right place to ask but is anyone able to confirm the copy protection used for Ultima II.
Many sources quote Wikipedia which claims it is Spiradisk. But actually all sources refer to the Hackers book. And in that the text is vague but it's about Garriott arguing against Spiradisk and the guy who invented Spiradisk and responsible for the copy protection of Sierra games, giving in and implementing the copy protection after all (a bit vague but it's hinting that he implemented the old copy protection).
Dick Sunderland called Duchaineau to tell him to copy-protect the old way. But Mark was still evasive. [..] Mark Duchaineau was in the awkward role of a hacker trying to stop another hacker’s worthy program from getting out. In any case, he agreed to copy-protect the product,
Also Wiki is not giving a source for the claim that the correct spelling is Spiradisc.
robbo007
Posts: 88
Joined: Wed May 23, 2012 2:56 pm
Location: Spain

Re: Ultima II for Apple II protection scheme

Post by robbo007 »

I have a copy of the original Apple II floppies. Maybe creating a dump with KryoFlux they can be analysed to see if it is the Spiradisk or not? Or maybe its better to do this via AppleSauce as I think its better.

4Am on twitter is the bet person to ask about this as he has done loads of work with Apple II copy protection.

Cheers,
minstrel_dragon
Posts: 1
Joined: Tue Jun 09, 2020 11:31 am

Re: Ultima II for Apple II protection scheme

Post by minstrel_dragon »

I recently analyzed the layout of Ultima II on the Apple II (Disk images found on internet archive, I believe these have been created with Applesauce). Here's my findings:

- Spiradisk is not used on these disk images. Instead, a standard track/sector layout is used.
- However, VTOC (the root block of the directory) has been relocated from Track 17 Sector 0 to Track 17 Sector 1. This prevents an ordinary directory listing.
- There is dedicated copy protection scheme protected by some self-modifying code. I didn't analyze the details of the actual protection, but probably will at a later time.

Best regars,
-markus
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