4 ms·

Why not just cut the wobble edge of a real CD off and attach it to a burned CD? Maybe you can shave the back of the shimmed wobble edge down, so that it won't

Why not just cut the wobble edge of a real CD off and attach it to a burned CD? Maybe you can shave the back of the shimmed wobble edge down, so that it won't stick out as much on the burned CD. This shimmed wobble can be your key for all the burned CDs you have. Maybe double sided tape can keep the wobble shim attached to your burned CD while still allowing it to be removable for other CDs. I've never had a Saturn, so I don't know what this wobble edge looks like in person. Am I missing something?

djsumdog 10y ago
I don't think you can't cut a CD like that. The moment you try to cut it with anything, it will probably crack (both for real silicon and CD-Rs).
Grazester 10y ago
I seriously loled at this. That would not have been a graceful solution to say the least. This isn't about hacking cdroms just to get it to run on the system. It is about understanding the intricate details of how it worked so that when the cdrom drive itself died you would have a way of playing those games along with full cd bloc emulation
sitharus 10y ago
it's not a physical wobble, it's a data track written in a wave-like path. You can't write it as all CD-Rs already have the spiral track so it's very hard to fake. It's similar to the Gamecube using the burst-cutting area to implement DRM - it's impossible to duplicate without a production setup.
JoshTriplett 10y ago
> I've never had a Saturn, so I don't know what this wobble edge looks like in person. Am I missing something? The video shows it: https://www.youtube.com/watch?v=jOyfZex7B3E#t=2m13s https://www.youtube.com/watch?v=jOyfZex7B3E#t=2m13s
- abrasive 10y ago
  The video's graphic is a bit of an approximation. In practice it appears that every second disc sector is displaced, IIRC. And they've got particular bit patterns written into them to produce a visual logo; these patterns (but not the actual logos) are checked too. The protection ring is visible to the naked eye for this reason. I can't find a picture, sorry!
  - 0xcde4c3db 10y ago
    I tried to figure out how to reproduce the logo at one point (10+ years ago, when people were less worried about dying drives). IIRC, it's that the EFM patterns used to make the pixels don't make valid Red/Yellow Book sector contents, which causes some weird behavior if you try to read them as such.
justabystander 10y ago
You're not getting very technical responses to this, so I'll bite. > Why not just cut the wobble edge of a real CD off and attach it to a burned CD? This would have a very low success rate, as the precision required to accurately cut off the wobbled edge on an original disc (and the target area on a CD-R) would a lot of upfront engineering as well as cost-prohibitive tools. Optical discs require more precise measurements than most people who favor the scrapbooking "cut-n-glue" solution can provide. This is just as long as we're pretending it's possible. Opitcal discs lose a lot of structural integrity the moment you start breaking/cutting them. The reflective portion where the data resides is on a thin film substrate at the back of the CD. Cutting that without outright destroying the disc or (at least reducing the operating life) would take significant effort, as would precisely healing the new gap from combining two separate materials without destroying the alignment of all those microscopic ones and zeroes. Not to mention that any adhesives you might apply to combine the two pieces would make that level of accuracy impossible, if not highly improbable. And then you have to hope the whole thing holds up while spinning. Even assuming you could get the two pieces to combine seamlessly, there's always the chance that you've done something that destroys the balance of the disc, which could have a number of unfortunate effects in spinning media. I don't think the Saturn drive spins fast enough for it to sling off and demolish your hardware, but it could cause data inaccuracies at the very least. I mean a company could attempt to do it for you, but it'd be cheaper and more reliable to engineer Saturn-compatible CD-Rs (or offer a disc-pressing service) at that rate. Considering the only use is to defeat old copy protection, it's not going to have a market large enough to sustain it. So you're going to have high prices, and low enough product sales that it would probably not be worth inviting the legal trouble. Even after all that, CD-Rs can have all sorts of QA issues that can affect their shelf life. And then you still have the problem mentioned in the video where the drive hardware fails. Replacing it with flash data is just a better long-term solution.

djsumdog 10y ago

I don't think you can't cut a CD like that. The moment you try to cut it with anything, it will probably crack (both for real silicon and CD-Rs).

Grazester 10y ago

I seriously loled at this. That would not have been a graceful solution to say the least. This isn't about hacking cdroms just to get it to run on the system. It is about understanding the intricate details of how it worked so that when the cdrom drive itself died you would have a way of playing those games along with full cd bloc emulation

sitharus 10y ago

it's not a physical wobble, it's a data track written in a wave-like path. You can't write it as all CD-Rs already have the spiral track so it's very hard to fake. It's similar to the Gamecube using the burst-cutting area to implement DRM - it's impossible to duplicate without a production setup.

JoshTriplett 10y ago

> I've never had a Saturn, so I don't know what this wobble edge looks like in person. Am I missing something? The video shows it: https://www.youtube.com/watch?v=jOyfZex7B3E#t=2m13s https://www.youtube.com/watch?v=jOyfZex7B3E#t=2m13s

abrasive 10y ago
The video's graphic is a bit of an approximation. In practice it appears that every second disc sector is displaced, IIRC. And they've got particular bit patterns written into them to produce a visual logo; these patterns (but not the actual logos) are checked too. The protection ring is visible to the naked eye for this reason. I can't find a picture, sorry!
- 0xcde4c3db 10y ago
  I tried to figure out how to reproduce the logo at one point (10+ years ago, when people were less worried about dying drives). IIRC, it's that the EFM patterns used to make the pixels don't make valid Red/Yellow Book sector contents, which causes some weird behavior if you try to read them as such.

justabystander 10y ago

You're not getting very technical responses to this, so I'll bite. > Why not just cut the wobble edge of a real CD off and attach it to a burned CD? This would have a very low success rate, as the precision required to accurately cut off the wobbled edge on an original disc (and the target area on a CD-R) would a lot of upfront engineering as well as cost-prohibitive tools. Optical discs require more precise measurements than most people who favor the scrapbooking "cut-n-glue" solution can provide. This is just as long as we're pretending it's possible. Opitcal discs lose a lot of structural integrity the moment you start breaking/cutting them. The reflective portion where the data resides is on a thin film substrate at the back of the CD. Cutting that without outright destroying the disc or (at least reducing the operating life) would take significant effort, as would precisely healing the new gap from combining two separate materials without destroying the alignment of all those microscopic ones and zeroes. Not to mention that any adhesives you might apply to combine the two pieces would make that level of accuracy impossible, if not highly improbable. And then you have to hope the whole thing holds up while spinning. Even assuming you could get the two pieces to combine seamlessly, there's always the chance that you've done something that destroys the balance of the disc, which could have a number of unfortunate effects in spinning media. I don't think the Saturn drive spins fast enough for it to sling off and demolish your hardware, but it could cause data inaccuracies at the very least. I mean a company could attempt to do it for you, but it'd be cheaper and more reliable to engineer Saturn-compatible CD-Rs (or offer a disc-pressing service) at that rate. Considering the only use is to defeat old copy protection, it's not going to have a market large enough to sustain it. So you're going to have high prices, and low enough product sales that it would probably not be worth inviting the legal trouble. Even after all that, CD-Rs can have all sorts of QA issues that can affect their shelf life. And then you still have the problem mentioned in the video where the drive hardware fails. Replacing it with flash data is just a better long-term solution.