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Will you share a link to your essay when its done?

0x00 sounds okay for DVD sector replacement, at least i feel so.

If i remember correctly SS areas of Xbox discs aren't stable, each ss range has different amount of readable sectors in the beginning and in the end, and if i recall it right the amount of readable sectors differs also between drives.

sarami wrote:

Of course, If you say all sectors in sector range should be preserved by zero, I don't say anymore.

Back then when we first started preserving xbox stuff we talked about this topic and agreed to skip ALL possible ss ranges, because we find that most likelly xbox skippes those ranges anyways. This is similar to SafeDisc and other PC protections where we skip bad sectors even if there may be some data readable.

I can't understand how to use the FixLevel/[FixLevel] bits.

if (Q-CRC of QCurrentSector is bad) {
    create QGenSector1 from QNextSector - 1
   
    compare 96bits of QCurrentSector and QGenSector1
   
    if (the difference is 1-bit) {
        QCurrentSector = QGenSector1
    }
    else {
       create QGenSector2 from QPrevSector + 1

       compare 96bits of QCurrentSector and QGenSector2

       if (the difference is 1-bit) {
        QCurrentSector = QGenSector2
       }
       else {   
          try to change each bit to opposite (Max 96 times)    // for the case when QCurrentSector and QGenSector are different
          if not success {     
             reread sector (*1)
          }
       }
    }

if (Q-CRC of QCurrentSector is bad) {
    create QGenSector1 from QNextSector - 1
   
    compare 96bits of QCurrentSector and QGenSector1
   
    if (the difference is 2-bit or less) {
        QCurrentSector = QGenSector1
    }
    else {
       create QGenSector2 from QPrevSector + 1

       compare 96bits of QCurrentSector and QGenSector2

       if (the difference is 2-bit or less) {
        QCurrentSector = QGenSector2
       }
       else {   
          try to change each bit to opposite (Max 96*96? times)    // for the case when QCurrentSector and QGenSector are different
          if not success {     
             reread sector (*1)
          }
       }
    }

if (Q-CRC of QCurrentSector is bad) {
    create QGenSector1 from QNextSector - 1
   
    compare 96bits of QCurrentSector and QGenSector1
   
    if (the difference is 3-bit or less) {
        QCurrentSector = QGenSector1
    }
    else {
       create QGenSector2 from QPrevSector + 1

       compare 96bits of QCurrentSector and QGenSector2

       if (the difference is 3-bit or less) {
        QCurrentSector = QGenSector2
       }
       else {   
          try to change each bit to opposite (Max 96*96*96? times)    // for the case when QCurrentSector and QGenSector are different
          if not success {     
             reread sector (*1)
          }
       }
    }

Who fixes the 1-bit error of QCurrentSector? Isn't it fixed by changing each bit to opposite?

doubling vowels.

Like this?

if (Q-CRC of QCurrentSector is bad) {
    create QGenSector from QNextSector - 1
    
    compare 96bits of QCurrentSector and QGenSector
    
    if (these sectors have 1-bit error) {
        try to change each bit to opposite (Max 96 times?)
    }
    else if (these sectors have 2 or more bit errors) {
        reread sector (*1)
    }
}

Question
(*1). How many times subdump reread the sector? If it can't get the good Q-CRC, is the sector written to file with being bad?

because FORM2 sectors have no EDC & ECC.

When was the data lost, quite some time ago?

For the DVD-DL method, it would need to have the Xbox Layerbreak as well or else the dump would include sectors from the middle zones (zeroes).