Saturn game protection ring

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Fabrizo

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This has probly been asked before and I just never read it or forgot about it, but is the protection rings on saturn disks physicly their or a form of digital code? People say that the protection can't be copied because no CD drive can read it other then the Saturns. Well, why can't the saturns disk drive be used to copy the games, such as in the case of Dreamcsat games? If it could be used to copy the games, then the protection ring could be copied to, right?
 

IceDigger

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it's physical. and there's no decent way to dump data from cd via the saturn, DC does it via the serial port or BBA (which doesn't exist on saturn).
 

mal

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Even if you could read the data and get it out of the Saturn via the communications port (netlink or some other way), how would you burn it onto a disc?
 

Curtis

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I would love to know how the saturns protection actually works. What is it exactly that stops the data from being copied? Data on a CD can only be one of two things - a 1 or a 0 - so how is it different to the rest of the data? There is that writing on the disc at the rim, but the can only be read as either a 1 or 0, just like the rest of the disc, surely?

*Curtis dons his fire retardant jacket - protection again flames and retards!
 

mal

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As Rysley illustrated so clearly, the ring is right on the very edge of the disc.

Even if you could read it, how would you tell the burner to replicate that?

As Arakon once suggested, IF you could rewrite the firmware in a burner you might be able to burn it, but who do you know that can do that?
 

keropi

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perhaps... assuming that the letters PRODUCED BY... are unreadable sectors and saturn checks the patern, (like safedisk) maybe it would be possible... but I do not have a cd to test... and maybe I am just being silly :) I don;t know... anyone knows how the protection actually works?
 

ExCyber

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Well, since nobody has actually dumped the ring (to my knowledge), it's not known whether or not it could be reproduced by a standard burner. It might be, though I wouldn't count on it.

As for this:

"Data on a CD can only be one of two things - a 1 or a 0 - so how is it different to the rest of the data?"

Strictly speaking, this is true, of course. The problem is that CD burners do not allow you to specify all of the data. Most notably, there is no SCSI MMC command (AFAIK) to access the IEC 908 / Red Book EDC/ECC areas (incidentally, I'm told that these are the areas used for the PSX copy protection). There are 3234 bytes of data in every CD sector - 2352 user data bytes, 784 EDC/ECC bytes, and 98 control/subchannel bytes . At best ("raw" with all subcodes), you can only read/write spedific data to 2448 (I think) bytes per sector - the EDC/ECC is handled automatically by the firmware or by an encoding LSI.
 

Curtis

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I see. The problem is not that the data is unreadable, but that normal commercial burner can not burn the same type of data to those sectors
 

ExCyber

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Here's a quick dump of what I can remember about the protection:

- Sega's patents and the operation of the check strongly suggest that the ring is a physically standard pit/land pattern. The patent doesn't cover the particular bit allocation, but it does strongly suggest that the Sega logo embodies the signature itself. Note that this does not imply that the pattern is simply an optical image; the patents specifically mention avoiding optical recognition for cost and reliability reasons.

- CD-ROM drives with stock firmware can't read past the end of a CD's TOC, so the ring hasn't been analyzed or ripped.

- Saturn discs seem to be padded from the end of the TOC to the ring area, most likely with Mode 0 sectors (although there's no data on this, it would be the logical choice, and Sega has shown a strong willingness to stick to industry standards when it comes to disc formats).

- We can't know whether or not a burner can burn the ring signature without reading it. It really just depends on whether or not the "pixels" are encoded into a standard sector layout (there's reason to believe that they are, but no proof, and even if the layout is standard there may be something else preventing a normal burn). Hacked firmware would probably be necessary to investigate further.

As an aside, the information on PSX I referred to earlier in this thread is completely wrong. Sony was in fact devilishly clever in coming up with their protection scheme: it uses the same encoding and area as the ATIP information (i.e. the stuff that the burner reads to find out how long the recordable area is, which write strategy to use, manufacturer of the media, and so on) on CD-R/RW discs. In other words, even if you got some shady outfit willing to produce "PSX CD-Rs" with the signature pre-written, your CD burner wouldn't know what to do with them - you'd need specially-manufactured CD-Rs and hacked burner firmware to make bootable PSX copies...
 

AntiPasta

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As an aside, the information on PSX I referred to earlier in this thread is completely wrong. Sony was in fact devilishly clever in coming up with their protection scheme: it uses the same encoding and area as the ATIP information (i.e. the stuff that the burner reads to find out how long the recordable area is, which write strategy to use, manufacturer of the media, and so on) on CD-R/RW discs. In other words, even if you got some shady outfit willing to produce "PSX CD-Rs" with the signature pre-written, your CD burner wouldn't know what to do with them - you'd need specially-manufactured CD-Rs and hacked burner firmware to make bootable PSX copies...
erm... take a look in this thread and scroll down to 7. PSX checks for Barcode or ATIP

quoting:

PSX laser look definitive not for any barcode or other

markings at the very inner ring side of the CD.

The PSX doesnt check intentionally if there exist some

ATIP info!

 

ExCyber

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AntiPasta: note that it says that the PSX doesn't intentionally check for ATIP info. The way ATIP works is just incompatible with the info that does need to be there for PSX, assuming a premanufactured "PSX CD-R". The post does have a pretty well-supported claim that they managed to find a way to create the same output by burning specially formed patterns (but not at the timing/positioning needed by PSX), so my conclusion about needing specially-made CD-R media is probably wrong to begin with...
 

Mr. Saturn

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As i got the Return Fire CD by Prolific there were two more things beneath the main RFIRE.DSK...

The first is the RFIRE.TOC (i think it is the same as an .ISO???)

The second is a program which he said is officialy by SEGA called SEGACDW.EXE

And a readme which said:

This is the disk image and burning software.

To burn a copy, you will need a Yamaha CDR100, on your SCSI bus.

Then give this command

segacdw -s 2 -i 4 rfire

The "4" following the "-i" parameter is the SCSI address of your Yamaha CDR100.

I have uploaded this program, maybe some of you can check it if it may be helpful for us....

http://www.sega-saturn.net/segaprogram.zip (44kb)

And btw: I have a Yamaha CDR100, but i can´t get the thing to work so i couldn´t test it in the past....
 

antime

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This program is described in the Write-Once CD-R System User's Manual and seems to be nothing more than a custom burning software for the drive that was presumably supplied with the development kit. Completely unrelated to the copy protection system.
 
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