 | Author: | Lord Crass (guest: search) |
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| Date: | Sun, Mar 04th, 2012 @ 03:33 ( . ) |
This one checks protection on every level 10 and up. It moves the head back to track 1, then moves 2 half-tracks back into the drive stop. After this, it uses standard job queue to read in sector 18. The first 2 bytes are transferred to the c64 and used as a memory address for a table. Instead of getting the $39 $00 bytes it needs, it gets $01 $07, which is a valid t/s link in the sector which is part of the file "G4".
It's easily cracked, but I'm not entirely sure how this protection is supposed to work. Should there be a second sector 18 on that track that only gets read after the head bump, therefore getting different data?
Nibtools should be able to handle a duplicate sector on a track, shouldn't it? |
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 | Author: | Pete Rittwage (registered user: 558 posts ) |
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| Date: | Sun, Mar 04th, 2012 @ 10:55 ( . ) |
Nibtools doesn't "handle" any protection... it just gets a sample of one revolution of a track. Duplicate sectors are no problem... |
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| Author: | Lord Crass (guest: search) |
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| Date: | Sun, Mar 04th, 2012 @ 12:26 ( . ) |
Do you know if this image was created from an actual, working original? |
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| Author: | Pete Rittwage (registered user: 558 posts ) |
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| Date: | Sun, Mar 04th, 2012 @ 15:44 ( . ) |
As far as I know, yes. It was sent by a European contributor. |
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| Author: | Pete Rittwage (registered user: 558 posts ) |
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| Date: | Sun, Mar 04th, 2012 @ 15:51 ( . ) |
I have another copy that was sent more recently that I can forward along...
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 | Author: | tixiv (guest: search) |
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| Date: | Wed, Sep 04th, 2013 @ 18:17 ( . ) |
I thin the disk might have the wrong tracknumbers on the tracks: maybe physical track 2 says it is 1, track 3 says it is 2 ... leaving physical track 1 before the one that says it is track 1, so the head would not bump at all on the original disk, but go to physical track 1 |
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| Author: | Pete Rittwage (registered user: 558 posts ) |
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| Date: | Wed, Sep 04th, 2013 @ 20:03 ( . ) |
This does happen- do you think it is on purpose and the protection checks for that somehow? |
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