What is the technical reason that Lite-On DH-401S can read PS3 game discs?

I came across this earlier http://www.warepin.com/lite-on-dh-401s-reads-ps3-discs/ which piqued my interest, since I had no clue how the PS3 gamedisc protection/filesystem worked.

After some checking into it, I found that the filesystem is UDF (normal, I think?), and obviously there is no additional encryption if this drive can get at the filesystem successfully.

So that just leaves the question: why can this drive do it, but no others? (Note: I have no bluray drive to test with…just going by what I’ve read online). Don’t really know where to put this post, but I figured asking here would be as good of a place as any. The more technical the answer, the better! :slight_smile:

EDIT: I’ve just noticed that the news actually seems to have originated from these forums: http://club.myce.com/f142/lite-dh-401s-can-read-sony-playstation-3-ps3-game-discs-243095/
Unfortunately all the posters seemed to care about was copying games…can anyone offer the reason behind this quirk?

Also, might be nice to move this thread into the Blu-ray sub-forum…sorry, didn’t notice it.

Why would usual programs give you the correct info (eg about the FS)???

There is nothing really special about the game disc filesystem, it’s just UDF.

[QUOTE=shuffle2;2571512]There is nothing really special about the game disc filesystem, it’s just UDF.[/QUOTE]

And that is not correct, because an apple isnt just an apple, an apple is a type of an apple.

I don’t really think you know what you’re talking about.

There does not need to be a file system (eg UDF) on a disc for a drive to copy sectors from the disc. The file system allows operating systems to see the files/folders and display them to you.

An audio CD does not have a file system but most drives can make a copy of it. An Xbox game disc has a very small DVD-Video that will display to the user that it is a Xbox game disc. You can see the files and folders if you stick the Xbox disc in a PC. However, the actual game data are not a normal file system and can not be seen by a PC.

RM

I know for a fact that ps3 game discs use normal UDF because I have inspected a disc dump. However I have no Bluray drive besides the one in my PS3, and would like to get one for my PC which allows reading PS3 game discs.
So instead of looking for the (now rare) DH-401S, I was wondering if anyone knows what prevents most drives from successfully reading the discs. I’m capable of modifying another drive’s firmware if 1) the target drive is flashable and has known cpu, and 2) I know what the issue is, in the first place ;p

P.S. - Audio CDs use ISO-9660, which has been standardized since before 1987: http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf

P.S.S. - Also, some drives can read all sectors from a x360 disc. Usually people use debug features of the firmware to accomplish this. The same holds true for Wii discs.

Read my answer again…

You may get a clue.

You are very incorrect about audio CDs. I have a copy of the RED book in my office and I can asure you there is no mention of ISO 9660 for CD-Audio. ISO 9660 was introduced in CD-ROM.

If you read my post again, you will see that I did not say drives could not read sectors from an Xbox disc. I was saying that a PC (the OS) will not see anything other than the small UDF file system that is on it.

RM

This is ridiculous. Please answer my original question or don’t bother responding. Also chef, posting vague and condescending remarks only makes you look like the fool.

Not a direct answer to your question but hopefully some helpful information:

If you have the knowledge to write firmware, perhaps you also have the knowledge to write a piece of software that logs all communication between the drive and the reading software. With that data maybe you could see what commands are failing on the drives that will not read the discs. Maybe there are other parameters available in the command descriptor block that will allow the drive to read the disc. Refer to the MMC spec for commands and parameters.

Years ago I helped write a DLL that logs all commands to and all data returned from a drive. The limitation was that the software being used to talk to the drive had to use ASPI otherwise my DLL would not work. My DLL would only intercept data that was intended for ‘winaspi32.dll’. It would capture the data, log it to a text file and then pass the same data on to the [I][B]real [/B][/I]‘winaspi32.dll’.

I have no idea what software is being used to read PS3 discs in the Lite On drive. If it uses ASPI, then maybe you could try something similar. If you can find the problem then write your own disc reading software for this purpose.

As Chef seems to be trying to explain, there are many types of UDF, just as there are many types of apples. As I tried to explain, the PS3 disc might very well contain UDF that can be read by most any drive with the correct OS or software. However, that does not mean that every part of the data on the disc is UDF. This would be true for Xbox games. Place an Xbox disc in a PC and you will not see the acutal game files in your operating system. However, the Xbox disc does contain a few files in the UDF 1.02 format that can be viewed but these are just the files that MS wants you to see. The drive can read (most of) the other sectors but the operating system does not recognize them.

As a side note, optical disc drives are not file system aware. They are not programmed to parse the file system (this is the job of the OS). Try burning a small BD ISO file (UDF version 2.50) to a CD and then view the CD in XP. The XP OS will say that there is no disc inserted. This is because XP does not know anything about UDF 2.50. The sectors on the CD will be proper as far as the CD-ROM spec goes but the data will not be understood by XP. Another test would be to install a BD drive in a PC that is running XP and then insert a BD movie disc, such as rented from the movie store. The standard XP operating system will not recognize the disc because it does not understand UDF 2.5. The same drive in Windows 7 will show the files and folders. Optical drives are programmed to read sectors (not file systems) that conform to the specifications that they are designed to read. A CD drive will read data from a CD as long as the CD does not violate the CD specs. Place a DVD or BD disc in a CD only drive and it will not be able to read it. The same is true for DVD and BD. They are designed to read sectors that conform to certain specs. It does not matter to the optical drive what the actual data or file system is.

RM

PS - You will probably get more answers if you refrain from being rude.

PSS - The ECMA-119 spec you linked to earlier clearly states on the first page that it is for CD-ROM (which does not include CD-Audio).

Hey - Thanks for the informative answer!

So sure, obtaining a normal BD drive and debugging is one way to discover the difference. However, I was probing to see if anyone else was already aware of the difference - perhaps it would save me from buying a drive that would end up being more difficult to play with than another.

To be honest, I am only experienced with GC/Wii discs…I have passing experience with x360 discs, and haven’t touched a CD-ROM/CD-Audio disc in years. Additionally, I have no experience with BD besides the PS3’s drive and disc images obtained from it.

Because of the vast lack of information on the subject, I was imagining the PS3 situation would be like the GC/Wii one, where most drives will actually refuse to read sectors at all (not just a FS problem). See here: http://debugmo.de/2008/11/anatomy-of-an-optical-medium-authentication/
However, since this specific Lite-On drive allows the OS to display the filesystem, my guess is that this isn’t the case at all with PS3 discs - and therefore the issue keeping other drives from nicely displaying filesystem contents is probably relatively simple to fix.
…and that’s why I got excited :stuck_out_tongue:

Anyways, it seems like you’re right - at this point I might as well grab whatever drive looks good and give it a go.