Atari Centipede’s Hidden Code Trap

During the peak of Atari’s success, one of the more unlikely tasks given to some of its coin-operated programmers, was to analyse potentially pirated versions of their games. This week, I thought we’d take a look at a legal case brought to the Canadian courts by Atari in 1981. I came across an interesting document in which one of Atari’s most experienced coders Ed Logg, analyses pirated code for the purpose of a lawsuit to be brought against an arcade distributor. The contention was that they were selling a game that bore striking similarities to one of its most successful releases.

The pirated game concerned was called Magic Worm. Created by Sidam (a notorious bootlegger of Atari games based in Italy) and distributed by Video Amusements of Canada Ltd, the game was very clearly a copy of Atari’s Centipede.

Magic Worm flyer
The flyer produced by Sidam for Magic Worm

Atari, in an effort to protect its assets (and at the same time fire a warning shot across the bows of any other unscrupulous businesses thinking about distributing pirated versions of its games) took Video Amusements of Canada to court with the intention of shutting down the distribution of Magic Worm.

Simply stating that “this game copied our idea!” is all well and good; but in a court of law, the case has to be proven beyond any reasonable doubt.

Atari Legal
One of a series of advertisements taken out by Atari in trade publications during 1981

In his affidavit, Logg speaks of the history of Centipede:

It took Atari approximately 10 months to develop and produce the first production version of the video game Centipede, which was conceived by Dona Bailey and myself working under contracts of employment with Atari. The computer program relating thereto took approximately fourteen man months to write and it is estimated that the total development costs of the video game Centipede exceeded US $500,000.00.

Coin Operated video games were big business. As you can see, just developing a single game required a large capital investment.

Dona Bailey
Dona Bailey pictured here in 1982. One of the designers of Atari’s seminal arcade title, Centipede

Taking Centipede as an example, the upright machine would sell at a price point of $1,999. Atari churned out precisely 46,062 of them during 1981. We can surmise that Centipede grossed income for Atari of over $92 million in hardware sales. Aside from 1979’s Asteroids, it was Atari’s second biggest hit of the Golden Age of video games. No wonder the pirates wanted a piece of the action…

Atari Centipede Flyer
Atari’s Centipede Flyer

Logg goes on the describe the game in some detail, and points out the obvious visual similarities between Magic Worm and Centipede. He states that the copyright notice had been removed, and amongst other graphical twists, the mushrooms on screen had been changed to apples. Even to the naked eye, there were clearly commonalities.

He then compares the game play of the two games:

Centipede is completely different in concept to any other game on the market. It takes place in the world of insects, in contrast to most other video games involving combat against hostile objects where the action takes place in outer space. To my knowledge, there has been no other video game showing images of a centipede….

…the possibility of another designer independently coming up with an identical concept is so remote as to be discounted.

These are all good points. If you’re familiar with Centipede’s game play (which I’m sure you are), check out this video of Magic Worm. It’s pretty obvious even to the casual observer, that Atari at least had a point:

But the real coup de grâce against Video Amusements of Canada was Logg’s assertion that the game hadn’t just been inspired by Centipede, its code had been literally copied.

But how did he prove this?

In April 1982, Atari was handed a PCB from its solicitors. They informed Atari that it had been removed from a Magic Worm arcade cabinet purchased from Video Amusements of Canada the previous month. Who better to take a look at the offending PCB than Ed Logg – one of Atari’s most experienced video game designers?

Ed Logg 1982
Ed Logg, known at the time as Atari’s “Golden Boy”, a name given to him after the runaway success of games designed by him such as Asteroids and Centipede

After noting the visual similarities of the two games, Logg dug into the code used to run Magic Worm. He explained:

As it was feared that companies or individuals would copy our game, but would deny that methods of electronic reproduction were used, Atari built in a “trap” which is almost impossible to discover, and, in fact, was not discovered by the manufacturer of Magic Worm. This trap consists of a particular data pattern that has no function. It does not create any image on the screen or any sound. Only with the help of special code is it possible to read this pattern, and understand the message it contains.

In other words, to read the code hidden within Centipede, you need a key – and the only company with that key was Atari.

When you read the Centipede code with the “key” code, the secret message built into the game must be translated from International Morse Code. Such a translation of the code reads COPYRIGHT 1980 ATARI. This particular data pattern also appears in the Magic Worm program.

Consequently, if one knows our special code, Magic Worm reproduces our secret message which is unique to Atari.

Sidam Magic Worm PCB
The Magic Worm PCB is a good example of how bootleggers had to work around proprietary chips. Since the POKEY sound chip used in the original Atari Centipede game was proprietary and not available for purchase, Sidam had to use a different sound chip instead and make modifications to the game program to work with it. (Credit: Jason Eckert)

I’d say that Logg’s evaluation of the trap was pretty hard to argue against. The code was a trap, designed to prove unequivocally, where the original code came from. As Logg put it:

This constitutes conclusive evidence that the manufacturer of this Magic Worm game copied substantial parts of our game by way of electronic reproduction.

Logg’s original Affidavit makes interesting reading and I’d urge you to look through it here.

Atari were not alone in their legal efforts. At around this time, many manufacturers of coin operated video games also had success in the Canadian courts in obtaining orders requiring the disclosure of the names of suppliers of pirated or copied arcade games. These are known as “Anton Pillar Orders” providing the right to search premises and seize evidence without prior warning. This was intended to prevent the destruction of relevant evidence – particularly in cases of alleged trademark, copyright or patent infringements.

But the granting of these orders were at the discretion of the courts, dependent on the facts of each case.

In one of the earliest Canadian motions for an Anton Pillar order, Williams Electronics, the manufacturer of Moon Patrol, brought a copyright action against several Canadian distributors of unauthorised copies Moon Patrol. On November 1, 1982, Williams obtained an order of the Court requiring one of the defendants to produce to Williams’ lawyers an affidavit setting out the names of its suppliers and customers of the allegedly infringing video games.

Magic Worm Cabinet
An original Magic Worm cabinet. A few of these are still around, especially in Europe where Sidam enjoyed healthy sales

From what court records that I’ve been able to unearth, the Atari case was heard in Canadian courts in December 1982, with Atari applying for what’s known as an “interlocutory injunction” – basically a court order to compel or prevent a party from doing certain things pending the final determination of the case. Presumably the request was to immediately halt distribution of Magic Worm.

Interestingly, the injunction was not granted, but the defendants were required to place a substantial monetary amount with the court, by way of security for Atari’s potential damages, should it succeed at trial. Any failure of Video Amusement to post this security would result in the granting of an interlocutory injunction.

You can probably guess how that went. Video Amusement were unable to come up with the cash, the injunction was served and distribution of the game immediately stopped.

So Atari, in a roundabout legal way, was able to cease the distribution of the game in Canada.

So there you go. An interesting case for sure, and one where the placement of some hidden code deep inside the guts of Centipede, designed to trap future pirates of the game, came to fruition.

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4 Comments Add yours

  1. TomTom says:

    That is a really interesting story, and some piece of history!
    Thanks for sharing 🙂

    Liked by 1 person

  2. Alessio says:

    Thanks for sharing. Well done Atari

    Liked by 1 person

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