'Vorpal and V-Max source code?'
Author:Jonathon (guest: search)
Date: Mon, Sep 12th, 2005 @ 15:02 ( . )


Hi all,

I used to be obsessed with CP since I got my first tape drive (yes, copy protected tape!).

Does anyone know where I could just read the actual source code to either V-Max or Vorpal? I know V-Max was about the best protection out there at the time, and the author said Vorpal was even more difficult to understand. I'd like to give it a shot now. Any links?


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'Vorpal and V-Max source code?'
Author:Pete Rittwage (guest: search)
Date: Mon, Sep 12th, 2005 @ 15:11 ( . )

Hi Jonathon,

V-MAX! is mostly understood and copyable. Vorpal and to a greater extent, Rapidlok, are tougher protections. I have been unable to remaster a Rapidlok keytrack that the protection will accept (track 36).

You can run one of them in VICE and CTRL-M to get to the monitor, then enter DEV 8: to see the currently running drive code. Save it out to a file and disassemble it, or walk through it with the monitor.

It's nasty.

Pete


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'Vorpal and V-Max source code?'
Author:Jonathon (guest: search)
Date: Mon, Sep 12th, 2005 @ 17:22 ( . )

Good to know. I ran VICE a couple of years ago, then that computer died and I never installed on the new one.

Is Lemon64 the best place to get 'original' copies of these games that will have the drive code and all?


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'Vorpal and V-Max source code?'
Author:JohnP (guest: search)
Date: Sat, Sep 17th, 2005 @ 16:06 ( . )

Tape copy protection... back on the Vic-20, I bought a tape that had a neat trick in it. The filename had a color control character that was the default character color. Unless you had changed the text color before loading, you would never notice the change when "Found xxx" was printed. When the program was run, it checked the cassette buffer for the leftover filename and for the control character.


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'Vorpal and V-Max source code?'
Author:Pete Rittwage (guest: search)
Date: Sun, Sep 18th, 2005 @ 18:02 ( . )

I love little ingenious stuff like that. I have a cracked program that searches for the greeting text in memory and formats the disk if it isn't found. :)

I would like to hear more about tape copy protection. I don't know much about it at all. How did they beat double-deck cassette dubbing?

Pete


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'Tape copy protection'
Author:Jonathon (guest: search)
Date: Wed, Sep 21st, 2005 @ 21:46 ( . )


I had a couple of progs on tape before I convinced my parents to buy me a 1541. :-)

One was Killer Caterpillar (a Centipede clone, IIRC) and the other was actually an educational game. The part I liked to play was called P.V., or Place Value.

I remember trying to load the other programs on the tape, but found nothing. I once disassembled the loader, and found that it seemed to actually have its own format, I believe.

Very bizarre. I was fascinated, but quickly moved on to the 1541 and Di-Sector after that.

Jonathon


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'Tape copy protection'
Author:Kevin (guest: search)
Date: Thu, Sep 22nd, 2005 @ 21:08 ( . )

Not sure if you'd consider this "copy protection", but I remember some tapes (Sword of Fargoal was one and perhaps Telengard) could not be run from disc.

They were both written in BASIC, so you could easily copy all the program files to disc. They did something funny with the memory if I recall correctly, which meant you had to "crack" it by changing some values (POKE something into a memory location).

I never really played much with tapes other than those two games. It seems that tapes inherently had built-in copy protection just by design -- serially read, so you couldn't really use a program to copy it. Like Pete said though, a tape-to-tape deck would defeat that easily though. I never had one anyway.


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'Tape copy protection'
Author:Kevin (guest: search)
Date: Thu, Sep 22nd, 2005 @ 21:12 ( . )

I just e-mailed a friend of mine who was quite adept at C-64 stuff. Maybe he remembers how he cracked the Sword of Fargoal tape.


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'Tape copy protection'
Author:Jay (guest: search)
Date: Mon, Sep 26th, 2005 @ 05:47 ( . )

The best way to dub tapes was to use something called Doubler which consisted of an interface which allowed two tape decks to be connected to your C64 simulateously and some software. Load the software then put in the source tape and a blank tape, hit play on one and record on the other and that was it. I think this was more successful than simply using a double cassette deck because the C2N output is different to that of a 'normal' tape deck.

Jay


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'Tape copy protection'
Author:Antitrack (guest: search)
Date: Tue, Dec 27th, 2005 @ 09:14 ( . )

You get it wrong. The FILENAME of a tape file can be up to 183 chars or something, but only the first 16 chars are displayed while using standard CBM load commands.
So where is the rest? It is in the tape buffer area at 033c-0400, and you can actually store not just filenames there, but also whole little evil machinecode routines, many times, parts of the autostart loader.

If you look at the normal load routines, you'll notice that a JSR $f7ea (at around f533) will fetch just this tape header. So do your own fileopen routines based on that, and you have the data you want.

ATT


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'Tape copy protection'
Author:Chuck Cochems (guest: search)
Date: Fri, Mar 04th, 2016 @ 20:50 ( . )

Many types of tape protection existed.

The simplest was the cassette buffer protection. This was done by including an ML routine or two in the tape header, which were called by the program. You could transfer the file easily enough, but the routine in the cassette buffer wouldn't be there, and the game would not work.

The fix to this was to also save out the cassette buffer after loading the game, and write a simple basic loader that loaded the cassette buffer, then the main game. The d64 if snakman that says "ass presents" in the directory is a simple example of that.

Another protection was to change the load address of the main game, but store it's real address in the header. so if you tried to load the main game by hand, it would crash the computer because it tried to store it at the wrong place. The loader on the tape would use a modified load routine that looked in the header instead of the program data for the load address (and that didn't blank the screen). this is fixed by copying the load address in from the header. Many old synapse tape games for c64 did this. Zeppelin was one example. this can of course also be combined with the cassette buffer protection.

Later, fastloaders were developed, which provided extra protection by keeping the stuff in special formats. The higher bandwidth output formats were much more sensitive to sound quality, and thus were much more difficult to dub. also they tended to have pulses that confused the automatic gain control of consumer tape decks, so the copy wold fail.


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