DM copy protection

[Adamo]

Posted by Doug Bell, on 06/09/2008 at 16:55 on
http://www.next-gen.biz/index.php?optio ... =1&start=8

Of course it is a difficult question to say how much more or less revenue a product would have earned with or without copy protection. The answer to the question is dependant on a number of factors including the effectiveness of the copy protection and availability of similar products at different price points with and without effective copy protection.

There are at least four different interest groups, with the lines between them blurred at times:
1) Software developers and publishers seeking to maximize the return on their efforts;
2) Paying customers interested in receiving value in exchange for their money;
3) Pirates interested in using the software while illegally minimizing or eliminating costs; and
4) Crackers interested in the technical challenge, notoriety and/or financial gain from circumventing the technical barriers to copying or pirating the software.

Each interest group offers up their own reasons and rationales to justify their actions. Crackers argue the copy protection is pointless because it can always be circumvented as if this somehow bestows their activities with some form of populist nobility. Pirates argue that they wouldn’t have paid for the product anyway, so their actions somehow don’t really amount to stealing from the developer. Paying customers are frustrated by paying for a product that is less functional or more cumbersome to use than the stolen version used by the pirate. Finally, the resources available to software developers to invest in creating software are limited by the revenue they earn and reduced by the resources invested in copy protection. All in all, this creates a tough situation to analyze.

However, as the developer of a must-have computer game (albeit from a couple of decades ago) that you had to actually buy, I may have the rare perspective to take a stab at the question. Back in 1988, cartridge games were rarely pirated while computer games were rampantly pirated. Most games were cracked within a week of being released, with probably significantly less than 1% of software remaining uncracked after two weeks. One notable exception during this period was the game Dungeon Master, which was the best selling game on several different personal computer platforms over a two-year period. Dungeon Master was first released on the Atari ST, and for the better part of a year the only way to play Dungeon Master was to own an Atari ST and to buy the game.

Dungeon Master exposed the fallacy in the claims of both the pirates and the crackers. The pirates who would never have paid for the game if they could steal it did pay for it. Despite a steadily growing bounty of fame and notoriety for cracking the game, the protection lasted more than a year. And the paying customer was rewarded with not just a minimally invasive copy protection scheme, but just as importantly, with the satisfaction of not feeling like a schmuck for paying for something that most people were stealing.

As the developer of both Dungeon Master and the software portion of its copy protection, I knew that eventually the copy protection would be broken, but that the longer it held out the less damage we would suffer when it was broken. We had the advantage of owning the patent on a floppy-disk copy protection scheme that required a $40,000 specialized hardware device to write the disks. It was impossible to create a disk image without this hardware, and the hardware itself was out of production. That meant that as long as there were enough layers on the copy protection, and these layers took long enough to crack, the only way to own the game was to buy it. The copy protection scheme took a couple of weeks to create, and while this added cost to the production without adding value for the customer, it was time well spent. The copy protection was based on many redundant, overlapping and isolated checks and cross checks. The copy protection was developed with the assumption that the cracker would be armed with a hardware emulator and developed with an awareness of the capabilities and limitations of the commonly available emulators of the time.

Dungeon Master had a greater than 50% market penetration on the Atari ST—that is, more than one copy of Dungeon Master was sold for each two Atari ST computers sold. That’s easily 10 times the penetration of any other game of the time on any other platform.

So what’s the lesson? That piracy does take significant money out the pocket of the developer and that secure anti-piracy schemes are viable.

[Crash.]

I believe that some of the important reasons for the success of Dungeon Master are as follows:

1. DM had transparent, trouble free copy protection which did not interfere with the ability to play the game.

This is not true for most games of the past or present. I know from ex-gamers that copy protection hurts sales, because people do learn from bad experiences with copy protection. The consumer that spends money on a game that can't be played because of copy protection is much less likely to buy other games in the future.

2. DM was very reasonably priced

Price points matter. If I go to a store that has games for $20, I'm likely to buy five. If they cost $60 each, I may not even buy one. When I bought Dungeon Master, it was priced less than most other games on the shelf, so my friend and I didn't have a second thought about buying our own copies. The game looked good, it had good reviews, and was affordable. We had no idea about the copy protection.

3. DM had high quality, long term gameplay, that was probably unmatched by the contemporary competition, and for years to come.

I really can't think of any other single Atari ST game that was as good or enjoyable as Dungeon Master. While the copy protection was certainly effective, one shouldn't underestimate how truly special this game is.

[Bit]

I began with the disassembling in that time just because of the reason that the original of my beloved game may die. Well, it's still pretty okay until today - just the CSB-utility-disc not, some sector with one of the character pics broken. I also never had the time to finish it (til today ), but I learned a lot - which I later never abused for similar works.

Reading that article, I'd really like Doug to find to that community, for asking him to release the old original for free for teaching purposes, like John McCarmack did with his old sources until Quake 2. At least the Amiga version is still missing here.
I mean - he's also 30 years older now - and surely has much more to tell...

[Gambit37]

Doug has visited here in the past, he knows all about us....

And you should make that 20 years older, not 30!

[Bit]

erm wait - he was FasterThanLight - means... it's us who aged faster... but we run offtopic with this.

As a programmer, I vote for a copy protection because I also need my money from my work, that's what I am living from (at least did it for a long time - we can also discuss if programmers lose skills in age or if the economics just want fresh meat that they can loot).

This does not include the time that I spend when being here i.e.
So I'm also glad that there exists a free world, where everyone can be a little part of a big work, that even can result in much better software than the one or other professional one.
But with that we end up in the question if such projects kill the professional work - and/or - if the professionals rob out the free ones...

[mikko]

... like John McCarmack did with his old sources until Quake 2.

Just plain Carmack without the Mc. And even Quake 3 source has been released already some time ago..

[ChristopheF]

If anybody is interested in fully understanding how the fuzzy bits (bits that give random values when read) were created on the floppy disks of DM and CSB for Atari ST, you should read the detailed analysis made by DrCoolZic in his document "Atari Copy Protection V0.8.pdf" available as an attachment to one of his posts here:
http://www.atari-forum.com/viewtopic.ph ... a&start=90

It is very technical, and requires that you first understand how data is stored and encoded on floppy disks, and how the disk controller interprets the signals it gets from the floppy drive, but it is worth reading I think.
Eventually I will update/fix the article I have on my web site with the additional information found in this document.

By the way, after exchanging some emails with the author of this document, I discovered something: it seems that each copy of DM / CSB (at least for Atari ST) is unique!

In sector 7 on track 0 (the sector that contains the fuzzy bits used by the copy protection), there are 3 bytes that are normal (no fuzzy bits in there) but they have different values in all the versions that I have! (10 PASTI disk images of DM, 5 PASTI disk images of CSB).

It looks like a unique serial number was written on each disk during duplication, making each disk unique...

I don't know what is the purpose of this?

[Gambit37]

That was because FTL figured if someone did manage to copy the game, they could identify the source disk the copy was made from -- I vaguely remember some comment by FTL about this.

...Though this rather supposes they would have to force people to register their copy first or something? Hmmm... doesn't really work, does it?

[Bit]

I always read just about the weak bits, but there was another protection-technic - a sector with a sector number that was impossible to write, because the floppy controller interpreted this 'string' as another command. Though - it was possible to write it!
I formatted a disc normally, then wrote the sector before the critical one as 'double sized' sector, but did hide the index information in the datas. After that, I wrote the index data (only) of the sector before again, this time as normal-sized sector - and voila, it then interpreted the hidden datas as index information for the critical sector - the header had been written
After all, now some bytes have been missed in the end of the critical sector - but - I think those have been without meaning (and exactly here information would have been save!).
So - the trick with the sector number was pretty fine - but that part was 'crackable' after all!

[ChristopheF]

@Gambit: That's what I thought, but as you say, I don't see how they could trace back a serial number to an individual?
Surely a pirate would not register his copy! So this does not look like a very practical solution.

@Bit: Have you found in the game engine a check for the 8th sector that has an invalid sector number? ($F7 instead of $08) ?

[Bit]

Hehe, I swear my version will also not format anything!

(While moving house atm, I found out today - I'm a weak bit too!)