02 August 2019, 19:14 | #1 |
MVG
Join Date: Feb 2013
Location: Olathe, Kansas
Posts: 215
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Leander Copy Protection
Ive heard different stories about how Leander had a hole punched on the disk as the basis of its copy protection.
But ive never seen any physical proof of this. can someone show me some screenshots or better. a pic of your copy assuming you own an original? |
02 August 2019, 19:44 | #2 |
CaptainM68K-SPS France
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It does not. This game use the Protec serial (long) track. the hole punched is a false story.
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02 August 2019, 19:48 | #3 |
MVG
Join Date: Feb 2013
Location: Olathe, Kansas
Posts: 215
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yep, i thought so. thanks for clarifying
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02 August 2019, 20:47 | #4 |
Registered User
Join Date: Sep 2008
Location: Gainesville U.S.A.
Posts: 771
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I own it and there is no hole. Codetapper asked me to make a video spinning the disk last winter. Not seen is the bright light behind the disk. Only two hands and no holding jig didn't help much either. Of course the Captain's word is always good enough.
ftp://ftp:any@grandis.nu/~Uploads/clenched/leander.AVI |
02 August 2019, 20:49 | #5 | |
CaptainM68K-SPS France
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Quote:
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02 August 2019, 22:43 | #6 | |
Ex nihilo nihil
Join Date: Oct 2017
Location: CH
Posts: 4,935
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Quote:
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02 August 2019, 23:09 | #7 |
Amigaholic
Join Date: Dec 2009
Location: UK
Posts: 4,725
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Flak on the C64 had a deliberate 'dent' in the disk surface as it's copy protection!
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04 August 2019, 21:35 | #8 |
Registered User
Join Date: Sep 2008
Location: Gainesville U.S.A.
Posts: 771
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I am dissatisfied with it. The max resolution for taking movies on my 2003 camera is 320x240. Scrap disk has hole pricked with a sewing needle, scanner lid left open and a flashlight placed on the window. In round numbers figure 3.5" disk 11" circumference 3/8" window would take 30 scans 12 degree intervals. With no reference points there's no way to prove the disk has been fully rotated. Flipping the disk and scribing a mark on the hub would work. But now there's no proof it's Leander disk.
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04 August 2019, 23:32 | #9 |
Zone Friend
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Weirdly Jon Burton who worked on it says a laser was used:
[ Show youtube player ] |
04 August 2019, 23:34 | #10 |
CaptainM68K-SPS France
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04 August 2019, 23:42 | #11 |
Zone Friend
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That's weird, what would he be gaining by lying in such specific detail ?!
I'm assuming the hole would be have to be bloody tiny due to the density of the data on the disk, a hole visible to the eye would've corrupted too much of the disk I would've thought. |
04 August 2019, 23:48 | #12 |
Puttymoon inhabitant
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I have Leander and I can confirm there is not any hole in any of the three disks. Checked against the strong light source, that would reveal even a tiny hole.
Unlike Clenched, I have a PAL version. Last edited by Predseda; 04 August 2019 at 23:57. |
04 August 2019, 23:51 | #13 | |
Going nowhere
Join Date: Oct 2001
Location: United Kingdom
Age: 50
Posts: 9,014
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Quote:
1). Its not even his copy protected disk system on Leander. It is 100% the same as DMA Designs protection system on Lemmings. 2). The protection track code and creation is by Psygnosis, and is on most of the Psygnosis games, Nitro, Shadow of the Beast etc, etc. Nothing, and I mean NOTHING about the disk system, protection other than the checksum check for a later level had anything to do with Jon Burton or Travellers Tales. |
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04 August 2019, 23:52 | #14 |
Phone Homer
Join Date: Jun 2006
Location: 5150
Posts: 5,789
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The game would have to be non Write protected for this to work?
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04 August 2019, 23:56 | #15 | |
Zone Friend
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Quote:
Last edited by mcbpete; 05 August 2019 at 00:13. |
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05 August 2019, 00:08 | #16 |
Phone Homer
Join Date: Jun 2006
Location: 5150
Posts: 5,789
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maybe it was used on a pre-release that skid row got hold of as that has platforms that can't be stood on.
theres also a US release might be worth checking does a IPF exist of this? - JOTD did the WHDload install supporting the NTSC vesrion. clenched version was US Last edited by Retro1234; 05 August 2019 at 09:30. |
05 August 2019, 00:39 | #17 | |
Defendit numerus
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 53
Posts: 4,479
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Quote:
We can calculate what is the maximum that would create problems The disc has a circumference (on the outside) of about 3,5*2,54*PI = 27,93cm The rotation speed is 300RPM with 2us MFM cells, so 100000 cells (on Amiga usually a little more). It is not difficult to have a gap of 5000 MFM cells for amiga disks considering that it writes all the sectors side by side. This give us 27,93/100000*5000=1,396cm. Ok ok, on disk inner tracks the circumference is lower and therefore the hole a little smaller. And again, this measures an arc and not a straight line.. But yes, the hole can be very big Anyway the problem at that point is not in the hole per se but the completely unbalanced and bent surface that would not allow a reading without errors. In any case a visible hole is absolutely possible and tolerated (if the writing is done specifically, a hole by damage in random position is highly likely to create illegible data). But for what? There is better method to make the same results (weak bits). |
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05 August 2019, 00:48 | #18 |
Registered User
Join Date: Sep 2008
Location: Gainesville U.S.A.
Posts: 771
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Now this laser is a new one on me. Imagine a lawn mower swath (track). The blades of grass represent the magnetized oxides. It's like saying an ant hole would influence how the grass was cut.
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05 August 2019, 03:29 | #19 |
Registered User
Join Date: May 2013
Location: Grimstad / Norway
Posts: 848
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I thought the point of a laser hole would be to create a weak bit that would give differing results on multiple reads? It would of course also mess up writes.
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05 August 2019, 09:46 | #20 |
This cat is no more
Join Date: Dec 2004
Location: FRANCE
Age: 52
Posts: 8,303
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disk format is the same as lemmings too (mfm). And at least Lemmings has checksums to see if someone tampered with the code (which triggers subtle bugs). Leander hasn't. Protection on Leander is a joke. Even for me (I suck at cracking)
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