About copy protections.

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Van anonymous

incognito ergo sum (109)

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17-09-2003, 14:33

Think for example MSX TED 2.6, that had this kind of protection. I think, that it was an excellent example of well made "social copy protection" that was also technically pretty good.
Yup, TED had that kind of protection. It even showed the full home-address of the registered user.
Unfortunately, at an MSX fair in the mid-90's someone stole my TED disk for a joyride, and it got spread on BBS's etc. so everybody thought I had pirated it! Sad Crying Evil

Van ro

Guardian (4118)

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17-09-2003, 14:41

well guyver, why didn't you crack the version earlier than? (remove the name)
you know that something like a copy is bound to happen when giving your's to a 3th party (which is a crime on it's own, right?!) Wink

But I agree, it scares the ppl of a bit. No one wants to see his/her name spread around illegal copies. But nothing is bullet proof... sight.

Might as well make Public Domain software

Van NYYRIKKI

Enlighted (5385)

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17-09-2003, 16:14

well guyver, why didn't you crack the version earlier than? (remove the name)
you know that something like a copy is bound to happen when giving your's to a 3th party (which is a crime on it's own, right?!) Wink

Hmmm... There is a difference between giving away and come under victim of crime. Smile

"Remove the name" is also so easy to say... If you remove the name TED does not start. If you remove the routine that prevents TED from starting, everything looks good, but TED will hang on disk menu. Try it your self... As I said, it was also technically pretty good. Rest of the details can be found from TED sources.

~NYYRIKKI

Van anonymous

incognito ergo sum (109)

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17-09-2003, 19:07

well guyver, why didn't you crack the version earlier than? (remove the name)
Like I had planned to get it stolen, tssss..

And I'm not a cracker, never was, and probably never will be. I only started coding a few years ago anyway.

Van parallax

Expert (70)

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14-03-2004, 20:56

Hi, just doing a nostalgic search on 'Parallax' got me into this old thread. Funny.


ARC was cracked by Dynamic Duo, IIRC.

I'v been hearing this rumour for several years now, but I have never seen this. Worth commenting on though. I'd love to see a cracked version, but as I have never seen it in the wild, I honestly think it was only a partial crack. ARC had a layered protection mechanism.


The dongle contained the music replayer, which CAS released earlier on disk for a promo.. So Erik (Dynamic Duo) was clever enough to rip that replayer and insert it into the original. or atleast he told me

The music player is indeed on the cartridge, but that isn't the protection at all. It is just used to preserve ram, making use of the cartridge rom as it was there anyway.

After all these years I don't mind talking about it. The cartridge contained some very specific logic, which means that writing to some out ports initiated a computation mechanism, which could be tested by reading it. This was detected at various levels in the game code: a random crasher in the interrupt code, an 'after level' check, and one or two (I forgot) in the level 5/level 8 transition code.

Each of these tests was coded completely differently, and involved self-modifying code.

I'm not saying it can't be done, but I am saying getting it out would be a horrific job, and would be error prone because of the repeated checks, and checks at later points in the game.

So again, I'd love to see a cracked version played through to the end Wink

Regards,

Cas Cremers

Van ms

Rookie (20)

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14-03-2004, 21:24

Let me reveal my copy protection than, although I think some copies already exists, so the code must be broken.

This protection was used for:
- ZHM (text-to-speech tool with dutch grammar for Turbo R)
- PSG Sampler (Sample tool for all devices)

What i'd done, was:
- First format a regular double sided disc
- Then on some tracks (e.g. track 100-120) I reformatted the track by using a different interleave value, instead of default 1-3-5-7-9-2-4-6-8, which is standard (2), I used an interleave of 4, so the sector order became 1-5-9-4-8-3-7-2-6
- As a result, reading those specific tracks became very inefficient (The disc needs to spin 7 times to read all sectors of a track, instead of just 2 times)
- My software check routine initiated a timer before loading data
- When the data was read to quick, it tried reading it again

- Now, if you copy this disc onto a blank (unformatted or "normal" formatted) disc, the interleave values of track 100-120 will not be copied over (but the data will)
- As a result, the disc will keep on reading data during boot and never end.

- Offcourse all routines were coded using self-modifying code and filled up with random data.

- Because there is no (reliable?) way of reading the interleave values, the disc can never (never say never...) be duplicated exactly. : Let me know if someone can copy it using Amiga, just for my curiousity....
- Off course you can try to patch the copy, by changing the checkroutine
- Disadvantage: I had to prepare every copy manually using a Philips Diagnostic utility which was able to format a track with user defined interleave values, using Philips Drive Controller.

Van anonymous

incognito ergo sum (109)

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14-03-2004, 21:57

Man, nobody has that utility! Do you still have it? Can you make a disk image from it?

There's a utility on PC that can read raw diskdata, so including gaps etc... It would read your protected disks fine.

Van Manuel

Ascended (15756)

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14-03-2004, 22:00

Cas Cremers

Hey Cas! Welcome to this forum! Smile

Van ms

Rookie (20)

afbeelding van ms

14-03-2004, 22:10

Man, nobody has that utility! Do you still have it? Can you make a disk image from it?

Do you mean ZHM ? Does nobody have this ???


There's a utility on PC that can read raw diskdata, so including gaps etc... It would read your protected disks fine.

A diskimage would not capture the interleave, so that doesn't work.

And reading raw discdata doesn't capture the interleave, because that is not a gap, but just the order the sector data is written.

Van Manuel

Ascended (15756)

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14-03-2004, 22:34


Do you mean ZHM ? Does nobody have this ???

I have it somewhere, it was in the pile of disks I got from Kasper Souren Smile
The label said "Zeg het maar", which made me think he had no clue what was on the disk... Wink

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