Leander Copy Protection

[lantus360]

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?

[dlfrsilver]

Originally Posted by lantus360

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?

It does not. This game use the Protec serial (long) track. the hole punched is a false story.

[lantus360]

yep, i thought so. thanks for clarifying

[clenched]

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

[dlfrsilver]

Originally Posted by clenched

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

Thanks Clenched

[malko]

Originally Posted by clenched

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

The old-fashioned way, it's the real stuff !

[BarryB]

Flak on the C64 had a deliberate 'dent' in the disk surface as it's copy protection!

[clenched]

Originally Posted by malko

The old-fashioned way, it's the real stuff !

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.

[mcbpete]

Weirdly Jon Burton who worked on it says a laser was used:

[ Show youtube player ]

[dlfrsilver]

Originally Posted by mcbpete

Weirdly Jon Burton who worked on it says a laser was used:

[ Show youtube player ]

yes and it's bullshit

[mcbpete]

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.

[Predseda]

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.

[Galahad/FLT]

Originally Posted by mcbpete

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.

Jon Burton is full of crap, I have no idea why he posted that video, especially as he's been debunked quite comprehensively.

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.

[Retro1234]

The game would have to be non Write protected for this to work?

[mcbpete]

Originally Posted by Retro1234

The game would have to be non Write protected for this to work?

Yeah just been looking around the web and it looks like this was mentioned here about a year ago - http://eab.abime.net/showthread.php?t=89662. So I guess the question is, why on earth did Jon make that video if it's just nonsense ?!

[Retro1234]

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

[ross]

Originally Posted by mcbpete

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.

I tried to think on the question of the size of the hole.

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).

[clenched]

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.

[NorthWay]

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.

[jotd]

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)