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metaleggman
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Am I just lucky?

by metaleggman Fri Nov 10, 2006 4:09 am

Hey, I was wondering something...People always talk about having problems when burning games for consoles at high speeds, so I am individual in that I can burn CD-R's for my saturrn at top speed and have had 0 problems so far? I use 120% and have done it with lossless and lossy copies amd have made about 20 or so games i think... Just wondering 8)
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JC
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by JC Sat Nov 11, 2006 7:32 am

The reason why it's suggested that you burn your discs at something like 8X, is because once your Saturn's lens starts to get more wear and tear on it, the weaker it becomes. When you burn a disc at 52X or whatever, you are asking the lens to work harder as it has to "dig deeper" for the data on the disc. At least that's the way I understand it anyway.
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TristanX
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by TristanX Sat Nov 11, 2006 1:25 pm

It's simple. Old console lens reads at slower speed. When you burn at high speed, the data positioning on the high speed disc is different from a disc that is burned with slow speed.
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metaleggman
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by metaleggman Sun Nov 12, 2006 1:36 am

oh, i burn at like 48x...so is it bad for the saturn to play highly burned games? As I thought a burner with faster speeds just burned games faster. if it did anything physically different, wouldn't that mean only 52X and above drives could read the CDs? :?
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by TristanX Sun Nov 12, 2006 6:14 am

metaleggman wrote:oh, i burn at like 48x...so is it bad for the saturn to play highly burned games? As I thought a burner with faster speeds just burned games faster. if it did anything physically different, wouldn't that mean only 52X and above drives could read the CDs? :?

Yes, high speed CDs gives Saturn a hard time to read. As I mentioned above, data on high speed CD is different from low speed ones. Old consoles reads CDs at lower speed. From what I remember, I think Saturn reads at 4x. I burn my CD at 8x for Saturn games since that's the slowest speed I could get from my CD-Writer and it works fine when I test run the games with this speed on my Saturn.
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metaleggman
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by metaleggman Sun Nov 12, 2006 8:42 pm

I guess I should reburn any of the games I play a lot. May explain some of the music bugs I have been hearing from "perfect" rips...
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lordofduct
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by lordofduct Sun Nov 12, 2006 11:32 pm

I am going to agree with metaleggman here on my pure luck of this matter.

That and from what I understand of a CD-R... it shouldn't matter.

First I'd like to say the Sega Saturn is a dual (2X) speed CD-ROM. As well I'd like to say that all CD-Rs no matter what speed you burn them at follow an identical standard selected upon burning (the are couple different standards and sector sizes).

Each sector is written and then followed by an error correction string, then followed by the next sector, etc., etc., in a spiral around the disk. The error correction stage is the same length may it be burned at 1X or at 48X, (unless you choose a different standard... as formerly stated). That error correction is there to assist in correcting any errors caused by:
A) scratches or dust
B) slowdown of drive
D) bumping of drive (shaking)
C) ... other acts of God
D) Errors caused during creation/burning

Speeding up the burn process 'should' only raise the chance of errors caused. It shouldn't make it more difficult for the disk to be read because the data is on the same spiral, the same length and width, and the 'divets' (as they aren't divets in a burned CD) are the same. A laser can't strain itself any harder then it already has unless you manually go into it and up the strength of the laser yourself (the Saturn has a little orange plastic screw on the side of the lense that can be adjusted... this helps with playing CD-RWs).

Error correction shouldn't degrade the life of your CD-Rom any faster then normal use already does unless you are playing totally destroyed disks with stains, magic marker and cracks all over it. In that case you shouldn't be even bothering as it will never work anyways. On top of that the error correction is mostly done electronically, not mechanically unless it really really has to.

For instance... this is how error correction works. All examples are shortened and actually do not represent REAL LIFE error correction algorithms:

say sector A has binary code 10010001
The cd's structure will actually contain the string 1001000111101
When the CD-ROM reads the string it knows the first 8 digits is the byte of information and the 5 following is error correction (11101). A predefined algorithm states that the first 2 or 3 digits will represent the number of 1s in the sector... it also states that the last 2 or 3 sectors will define the numbe of 0s in the sector, and the last rule is that all 0s in the error correction states there is the same amount of 1s as there are 0s.

Our error says 11101 broken 2/3 will yield 11=3 1s and 101=5 0s. And in 3/2 it will yield 111=7 1s and 01=1 0s. It looks over the original sector and counts up the number of 1s and 0s and notices there are 3 ones and 5 zeros. It decides that the error string is written in the 2/3 way and does match so there is nothing wrong. This was all done through a chip, not by rereading the sector. It will only re-read a sector IF and only IF it reads multiple sectors and continually can not figure out the error correction.

For instance, what if it read:

1001100111101

The error correction is the same, 11101, so there must be either 3 ones and 5 zeros, or 7 ones and 1 zero. But it read 4 of each... (whos error correction should of yielded 00000 so says the algorithm), It the algorithm states that the error is going to be of a smaller margin (as it should) then the larger margin... as it only reads 4 ones and not 7 or 3. The smaller margin is in the direction of the 3 (margin of -1) and concludes that the error string is written in the 2/3 format and there is actually 3 ones and 5 zeros.

Now if it read 11011001 11101
The margin is equal in this case... it considers that a bad sector. If it is followed by a similarly difficult sector that has a close margin like that, it will THEN go back and reread the sectors over. It is extremely debatable if this degrades the life of the CD-ROM... mainly for the fact most CD-ROMs won't even bother rereading and just consider it bad sectors.

Also burning CDs at higher speeds should not cause extremely high rates of error. If it does it isn't the speeds fault... you have a crappy CD burner/media.



BUT... I will say, SOME games use very little error correction (i.e. Dreamcast is notorious for this, along with its thinner spiral.) so that more data can be crammed onto the disk. Higher speeds with its higher margin of error may cause the game to be unplayable... but won't cause it to strain your CD-ROM.


One last thing I want to discuss is that of what the data looks like physically on the disk. In manufactured CDs they are divits in the disk that will bend the laser so it doesn't bounce back into the lens. If the laser bounces back it is 1, if it doesn't bounce back (it doesn't see anything) it is a 0. With CD-Rs on the other hand you can't actually 'melt' tin. It doesn't get hot enough. Instead they cover the plastic layer in a chemical and then place a reflective tin over that. When the chemical is heated it turns opaque and light can't travel through it anymore. So now instead of bouncing the laser away... it just doesn't reflect. To the mechanism of the CD-ROM it doesn't notice the difference... the only problem is the chemical is opaque so 'some' light still passes through and there are some CD-ROMs that will pick up on that. But the Sega-CD and Saturn aren't that annoying.

Either way, no matter the speed, the chemical is heated in its appropriate pattern, same length, same all that good stuff. If the lengths were different from speed to speed, then disk space would be variable in congruency with it's speed. Meaning that a 48X disk would supposedly hold more data then a 1X disk. But they don't, so there isn't a difference in size.

Further info... CD-RWs use a crystaline substance that is opaque. When heated it crystalizes and turns clear, when heated to a higher temperature it liquifies and turns opaque again. CD-RWs are then actually burned in the opposite manner. Either way though the resulting disk is still the same concept, the only problem is you need a very sensitive drive to read these disks as even the crystals are slightly opaque and the laser is harder to pick up. Reading these disks does require a lot more work from your CD-ROM.

Congruently, CD-Rs require more work then legite disks, but the speed it was burned at doesn't effect that. It is inherent in the fact it is a CD-R.


Then again I may be wrong. But I've own my Sega CD since 1993 and my saturn since 1999 (bought it off a kid who already owned it for 1 or 2 years). I've been burning backups since my purchase of my Saturn... so that is 7 years of back up play on very old hardware and I'm far from a light gamer, many day+ long gaming sessions in there. They still work perfectly fine and only had one hard time burning a Sega CD game... the first time I did it, and it was at single speed... the problem merely was my innability to understand the whole mix mode crap and went bin/cue ever since.
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metaleggman
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by metaleggman Mon Nov 13, 2006 3:34 am

cool. I didn't really want to re burn all 25 or so of my saturn games. Fortunately the ones that have errors are ones I don't really like :D
I'll burn games slower in the future, just to try to keep errors to a minimum. Thanks folks :)
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lordofduct
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by lordofduct Mon Nov 13, 2006 3:43 am

I should really emphasize the true size of real error correction. CD-ROMs use atleast 2 forms of error correction (some don't even take place on the disk). The complexity of these error corrections would require very bizarre damage to be done to the disk for the error correction to fail. They utilize error correction through a sector, on a block and around a matrices of sectors. For it to fail would require an entire block of information to be damaged in a LOT of areas. The error correction is even implemented on the error strings as well so that it is doubly protected. Even the simplest forms are Extremely good.

The chances of burn error screwing up in an undisturbed burn is infinitely small. Read buffer underruns, burn failures, or other errors that would be logged and displayed to you during burning would introduce these errors... you'd know before taking the disk out and playing it.

The real culprut of the damage is YOU. Handling your disk poorly, age (CD-Rs don't last long), scratches, dust. Don't ever expect to burn a game and keep that disk as the master. Keep the master on your HDD or some other intricate storage that won't suffer from such damage.

I have backups yes, I burn a game on 5 cent disks and use them till I lose them (which is REAL fast) and just burn em' again.

note the CD-Rs all over my desk:
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metaleggman
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by metaleggman Mon Nov 13, 2006 9:17 pm

Is keeping them in sealed DVD-Rs alright? I mean if they are in their case and in a safe place, you think they will last a while? I have a tiny 148GB HDD, so keeping all my copies on me HDD wouldn't be good >.<

btw, damn tha screen is bright 8)
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