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  TEXT               Savegame Editor Construction Kit                 TEXT
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  Theme : Game recognizes modified savegames...         date : 04.01.1996 
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                  ( English conversion date : 08-01-1996 )

  There are also some games which check, wether their savegames has been 
  modified or not. Sometimes, having recognized such a modification, they
  do not accept the savegame, or they set all values back to the start 
  values. This does not happen very often, 'cause lots of programers
  don't care about the savegames that much.But what can we do in this 
  unexpected case ? What to do, if the modification isn't accepted such as
  in Wolfenxxxxx 3D(TM), Transport Tycoon(TM) or Corridor 7 (TM) ?
  
  I have to admit that there is no basic recipe what to do then.
  To protect savegames against modification, there is a checksumme
  stored anywhere, most times in the savegame itself.
  In a very simple case, this could be an addition of all the byte-values
  of the file.Each simple change causes a wrong checksum and will be enough
  to prevent the access to the savegame.In this case, you could play a trick
  on the savegame by adapting the checksumm. You would have to modify 
  two values of the savegame.If there is, for example, a 3 in any position 
  where you would like to have a 100. If you do the change, the checksum 
  will be higher (+97). So if you'd manage to decrease one of the minor 
  byte values (e.g. of a graphic) for 97, the checksum would be all right 
  again !
  But as I already said, this method of protection is the simplest of all!

  To find a way, you'll often have to do a lot of efforts and spend a lot 
  of time in front of your computer.You also could look for two values 
  one after another, which are different in every savegame.But you'll have 
  this often which makes things more difficult.
  The savegames with hundreds of differences are also often hard to analyse
  if you're looking for some kind of checksum.

  If you do know an example for an anti-modification-protection in the 
  savegames, you could write it to me so that I can integrate it into SECK 
  in a future version.







