What is the scientific explanation why we need mod chips?

[thewessman]

I have a little bit of understanding about the reason for modchips. If I understand it correctly, the media (cd, dvd) has some sort of data on itself that tells the game console that it is a legitimate piece of software. If that is the case, then why is that data unrecordable, why can't software copy that data over to another media, especially when doing a 1:1 copy?? I understand that a modchip bypasses the cpu's authentication process either by giving the cpu false authentication data, or simply by ignoring it all together. The question still remains, however, why can't an exact backup, be an exact backup?! Are the reading devices simply not capable of reaching the data sector, and if so, how come the readers in the consoles are able to? If we were able to make a true 1:1 copy, then the recorded media should be identical to the original, but since we must use modchips, then it is safe to assume that the copies are really a 1:.999 ratio.

[psx_paul]

Originally posted by a very wise man :)

Originally posted by Charlie_ps2
Why is this all necessary? Sony have tried to stop you using copied games by going through some clever pre-boot stuff that identifies from data & deviations pressed into the pre-groove section of the CD/DVD whether or not the media is original. So we must fool the PS2 into thinking that a valid game has been booted..

[thewessman]

very wise indeed. I did some searching and didn't find anything, sorry if I asked a redundant question. Can you post the link to that comment?

So basically there is a physical difference in the CD/DVD that is a major part of the verification process, which cannot be coppied onto a DVD-R because DVD-RW drives are unable to make physical changes to the disk.

Here is a solution that would work instead of using a modchip. Buy an electron microscope, and a very small tiny needle, and make the physical changes by hand.

[psx_paul]

http://www.fileforums.com/showthread.php?s=&threadid=48609

22825 views - wow :eek:

[thewessman]

Ah, no wonder I missed that comment. I read through that tutorial, but it didn't really give me too much useful info, so I skimmed the second half and was done with it.

Thanks for taking the time to post the link.

[psx_paul]

no probs :)

[seaneyb2003]

needs updating huh? bit old. where is good old charlie ps2?

[TylerDurden]

Originally posted by seaneyb2003
needs updating huh? bit old. where is good old charlie ps2?



He's still around. Just not posting.

His last activity is:

2004-05-03 23:19:32



;)



Tyler!

[seaneyb2003]

oh ok hes sneaking around the forums then huh

[TylerDurden]

Yup.



Tyler!

[ihaveanosebleed]

I don’t know if this still holds true but a very long time ago I read some information from, I believe it was the “hitmen” group, who released the ISO License patcher. Pressed CD’s were made with bad checksum values in the boot sector. You can read the ISO Data to your computer 100% but all consumer burners automatically write good checksums to sectors when it burns so the Backup is detected as not being an original. There were rumors of a certain burner that with a firmware hack could make a perfect working backup. As the years went on without hearing any more about it, I assumed it was indeed just a rumor.

If a checksum is the ONLY variable in the detection process you would think a firmware hack or some type of burner Modification to inject the proper boot data would have surfaced by now. I think there is probably more to it. Say a burner was hacked to burn the proper boot data, which shouldn’t be that hard of a MOD. Just a programmable micro controller like a PIC or Atmel to time the data stream and inject the code at the right time. Would a Burned CD with good boot data physically be able to boot? Is the data burned on a CDR in the exact physical location as the original? CDR’s are not laid out exactly like Pressed CD’s. CDR’s have laser calibration areas, media identifiers and things that tell the drives what media they are reading.

When a PS1 boots a CD, the first thing the drive controller does is bring the laser all the way in as close as it can physically go to the hub and then tries to read a CD. When a PS2 boot, it brings the laser all the way in but then jumps it ahead about 1/8th of an inch. It would seem the PS2 is capable of reading closer to the center of a disk than a PSX. I don’t know if this is for DVD media or what?