[(Pre-)Release 0.1.0] TwinStepper – Assists in creating working CD-R(W) backups of ProtectDISC CD

First of all: The important Disclaimers!
I'm serious about this! The disclaimers are important and I mean everything exactly as I wrote it down. Nevertheless I put them into a spoiler to not clutter the entry. That doesn't reduce the importance.

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This entry is part 4 of a series:

1. Laura’s Preschool 2 (Lauras Vorschule 2) – pictures about 800KB
2. Sinchen vs. ProtectDISC (CD version) – Pictures < 370KB
3. Video proof (as good as I can) for the last entry

TwinStepper – Assists in creating working, non-emulation CD-R(W) copies of ProtectDISC CD​

This entry contains the source code of a tiny application that can patch raw CD images with equally distanced twin sectors in some areas. Burning such a patched image to a CD-R(W) in RAW-DAO mode (RAW-SAO+SUB96 should suffice as well, but RAW-DAO is better), will result in a disc which exhibits lower data density than normal in the regions where the twin sectors have been inserted. This approximation is often good enough to fool the disc check without the help of any DPM measurement and without RMPS emulation.

I'm not very creative with naming (and names aren't really important for me). The program creates a twin sector, steps over the next sectors and so on, so... I just say TwinStepper.
The complete write-up about my little research is not finished yet and won't be finished anytime soon. Due to my concentration issues no estimation is possible -- but I work on it regularly. The write-up will contain much more information as well as test results how various copies fared in various drives (only so much: Very promising results; much better than I ever dared to hope before starting this project).

Only a very small modification of the image is really needed (and strictly speaking TwinStepper applies twin sectors in way too big region -- shouldn't be a problem).

One serious limitation right ahead:​

"No emulation and no helper software required" can only be achieved with very old optical drives (read-only drives and "real" Plextor writers). ProtectDISC checks the ATIP data in addition to the data density check. This will give away the usage of CD-R(W) on all current optical drives: They are all writers and capable of reading ATIP. Back when CD protections played an important role, dedicated readers were readily available, so please see it in context of the past. Note that "pirates" professionally distributing bootlegs of top-games wouldn't have hit any hurdle beyond the data density. Everybody with access to CD pressing machines would have burst into laughter about the ATIP check.
I don't have any knowledge about mastering and pressing equipment – what it can do and what not, but I know that many protectionists advertised their products also with protection against professional bootlegs. Well, if mastering equipment would just adopt the faked density from a Twin Stepper ProtectDISC CD-R copy, the pressed result would run in the majority of drives. I imagine mastering machines being able to adjust the pit length by 1% to 1.5% by themselves, nullifying the need for any crude method such as twin sectors.

Successful copies (games starting from CD-R just like from legit CD-ROM in most of my drives):​

• Lauras Vorschule 1,2,4 (not 3 yet– it was too expensive to buy at the moment – but I'm confident it will work)
• Die Reitakademie – Das entscheidende Turnier
• Ankh 3 – Kampf der Götter
• RTL Biathlon 2007
• Devastation (ProtectCD v5.x, requires manually entering different values into the source)

This covers ProtectDISC versions v7.x, v8.x and v9.x. In no case the simple modification was insufficient. The oldest, Devastation, which required manual adjustments, deviates less from a normal CD in terms of density: Two out of the four drives in my Windows XP computer started the game from a simple CD-RW copy without any image modification. The oldest version didn't check ATIP either. I hope to get my hands on a v6.x as well.

Last comments:​

My detection method for checking images for usability is bad, simple and error-prone – but mostly working for me and really fast.
Not all drives handle twin sectors alike. There is no guarantee that the method is compatible with a particular drive. Especially the wide-spread LG drives are problematic.
If I get more original CDs, I'll test them as well. More information is within the detailed comments in the source files. I will not provide binaries for the following reasons:

• I'm Linux user, but the target platform is Windows (back to 98SE or at least back to XP). No Windows development tools right now.
• Again: For the unlikely case anybody actually wants to use this, they have to compile it. If one has to compile it themselves, they can't say: "I accidentally ran your program and the following bad happened:[…]" – some reading has to be done before being able to start the program
• It is an early alpha and not end-user ready. Therefore: No manual, not sharing my experiences (yet).

Source Code attached. Password for the archive is:
I accept the Rsiks!
With the intentional typo, but without the blanks between the words.

If you made it here:
Thanks for reading this mess of a blog entry!