Difference between revisions of "Weak sector data"

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= Weak disk data =
 
= Weak disk data =
  
Some copy protections have what is described as `weak, random or floated' data.
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Some copy protections have what is described as 'weak', 'random' or 'floated' data.
  
Each  time the 'weak' sector is read one or more bytes will change, the value
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Each  time when the 'weak' sector is read one or more bytes will change. Their value
 
may be random between consecutive reads of the same sector.
 
may be random between consecutive reads of the same sector.
  
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Weak sectors used by [[Speedlock]] copy protection family for [[ZX Spectrum +3]] disks.
 
Weak sectors used by [[Speedlock]] copy protection family for [[ZX Spectrum +3]] disks.
  
Usually weak sector data used with other things for copy protection:
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Usually weak sector data combined with other unusual things for copy protection, such as:
 
* different sector length for different tracks
 
* different sector length for different tracks
* different sector length within a drack
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* different sector length within a track
* deleted sectors
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* sectors marked as deleted
 
* sectors with CRC error
 
* sectors with CRC error
 
* wrong sector header informations e.g.:
 
* wrong sector header informations e.g.:
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Unfortunately, disk images with recorded weak sector data is very rare (There is no any disk image with weak sector data on [http://www.worldofspectrum.org/ WoS]).
 
Unfortunately, disk images with recorded weak sector data is very rare (There is no any disk image with weak sector data on [http://www.worldofspectrum.org/ WoS]).
  
So if a game read the same sector repeatedly than semulators assume that sector has weak data..
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So if a game read the same sector repeatedly than simulators assume that this sector has weak data..

Revision as of 17:57, 13 February 2016

Weak disk data

Some copy protections have what is described as 'weak', 'random' or 'floated' data.

Each time when the 'weak' sector is read one or more bytes will change. Their value may be random between consecutive reads of the same sector.

Weak data recorded with only modified hardware, so you cannot copy these disks without 'crack' the copy protection.

Only two disk image formats (Extended DSK and UDI 1.1) can store this type of data.

Copy protection

Weak sectors used by Speedlock copy protection family for ZX Spectrum +3 disks.

Usually weak sector data combined with other unusual things for copy protection, such as:

  • different sector length for different tracks
  • different sector length within a track
  • sectors marked as deleted
  • sectors with CRC error
  • wrong sector header informations e.g.:
    • track number
    • too long sector length

Disk images with weak sectors

Unfortunately, disk images with recorded weak sector data is very rare (There is no any disk image with weak sector data on WoS).

So if a game read the same sector repeatedly than simulators assume that this sector has weak data..