Twin Sectors Challenge

vbimport

#1

I have a challenge for all the budding CD experts out there.

Blackchecks phenomenal Twinpeaks discovery has been around for quite a while now (and it’s still the best way to backup SecuROM discs IMO).

  1. Tell me (and prove it to me) how to reliably find duplicate or twin sectors, such as those used by twinpeaks to allow backups of SecuROM games. (Why haven’t Sony been able to do this yet?) Your solution must work on the majority of CD or DVD drives (not just Plextor or Toshiba - or others that don’t like twin sectors)

  2. Alternately, prove to me why you CAN’T detect twin sectors!


#2

beacose when the drive finds out that the 2 sectors are the same(duplicate) it returns only one of them but internaly it reads both sektors so it will return one sektor as usual but but a litle slower beacose the drive need to read both sektors !!!
Actualy it is not possible by software to detect twins !!! since the drive wont return any error or something like that , it returns the same data as the original disk and thats why sony canot do shit about twins !! they are relying on drives that will report an error if the drive finds 2 SAME sektors (drives not compatible with twins)!


#3

I like your reply, it has merit, but it relies on certain assumptions that might not be correct for the majority of drives out there.

Certainly the Plextor and Toshiba drives return a read error if (a) twinsector(s) are found.

I presume that they do this because they don’t know which sector to return - even though they are identical. I guess it must be something to do with the read-ahead logic?
(Someone correct me if I’m wrong?)

Certainly the Liteon drives “ignore” the twinsector.

An interesting or perhaps useful side-effect of the disc images created during the early Twinpeaks days, was that if you put too many twinsectors on a disc, the Liteon drives could no longer read the ATIP of the media. Now this might be useful in the future.

Try it for yourselves, next time you back up a SecuROM disc, using Twinpeaks 0.2, select a higher value for the number of twins to insert.


#4

Well, if after all this time if sony (and anyone else) hasn’t found a way to detect them, then it’s not really an assumption. It must be true of death-heaven’s statement.

By the way the detection of ATIP is a flaw of the Securom check - not of the drive. You will still be able to read the ATIP using an atip reader program, I tried this myself.


#5

Hi Truman.

I’m with you.

Whilst in the process of investigating Tages protection, I wrote a few utilities, and one was specifically to try and detect twinsectors.

I couldn’t manage to do it, but I suspect that the author of KProbe probably could.

The Author of DaemonTools has said on the forum elsewhere that “Twinsectors are easy to detect”, but I’ve yet to see any evidence.

If we can manage a way to reliably detect twinsectors, then this would make the basis of a very good protection mechanism.

When we hit the jackpot, I fully intend to share it with everyone else! :eek: :iagree:


#6

Originally posted by Truman
[B]Well, if after all this time if sony (and anyone else) hasn’t found a way to detect them, then it’s not really an assumption. It must be true of death-heaven’s statement.

By the way the detection of ATIP is a flaw of the Securom check - not of the drive. You will still be able to read the ATIP using an atip reader program, I tried this myself. [/B]

If you try a very high value for the density of the twinpeaks, the ATIP does “disappear” even with special ATIP reading programs, well at least with my Liteon burners it does! Really, truly.


#7

the drive return am error beacose the drive stick 100% to the standard and on a standard disk its not possible to have the same sektor writen twice and thats why some drives as toshiba return an error but other drives witch dosn’t respect 100 % the standards like liteon does return the contents of the sektors witch are identical but it returnit like was only one sektor !!!
its a way to mess with the standards and thats why some drives give errors on twinpeaked thisks and other read them witchout problems !!!


#8

for an example : try making an image of a twinpeaked disk and the original disk (asuming you are using a twin capable drive) and then compare them , you will see no diference and a image normaly contains ALL the information that the drive can read off the disk and you can see that in the image from the twinpeaked dhisk there are not twins sektors,but plyn sektors (not doubled) thats a proof that the SOFTWARE canot read twinsektors again once thay are burned to disk !
-there is no possible way that the drive would return both sektors and only if the drive could return both sektors only then you can detect is a twinpeaked disk !
-the only way to detect it is to implement some new commands into the firmware but thats less probable !!