I am almost 100% sure this patent describes DM CSB This patent was granted to Software Heaven Inc the maker of the games DM CSB and fig 1 & 2 describes exactly what is used for protection (fuzzy bytes) in these games.Steven Seagal wrote:I also have doubts about this patent being for Dungeon Master. What they do seemed to be different when I read it, but maybe I misunderstood, can't explain the differences from memory, just that I removed the reference in Steem doc.DrCoolZic wrote:Weak bits in 4.11.3 are presented for reference as they are described in patent "US Patent 4,849,836 *** Copy Protection for Computer Disks - Used in Dungeon Master, Chaos Strike Back ...." *** http://info-coach.fr/atari/documents/ge ... 849836.pdf found in page http://info-coach.fr/atari/software/pro ... references
As described in the pattent these are real "Weak bits" (as they produce weak signal) that results in fuzzy bits.
Refer to detail explanation from Gothmog on Dungeon Encyclopedia Web site http://dmweb.free.fr/ specially http://dmweb.free.fr/?q=node/210
I do not know why they describe weak bits with these strange techniques presented in fig 3,4,5?
As far as I know these techniques have probably never been used because it would require very specific mastering machine with very very special floppy drive.
But all of them would result in weak bits in a different way that what we are used to. These techniques would result in Weak ANALOG signals (due for example to head misalignment) and the conversion from analog to digital would result in different values returned because the analog signal would be close to the detection threshold.