10NES

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10NES chip from Super Mario Bros. / Duck Hunt cartridge

The 10NES system is a lock-out system designed for the American version of Nintendo Entertainment System (NES) video game console.

Various companies found ways to bypass the authorization chip.

Contents

[edit] Design

The system consisted of two parts—a computer chip in the NES that would check the cartridge in the system for authentication, and a chip in the cartridge that would give the 10NES code upon demand. If the cartridge did not provide the authentication, then the system would not boot up. The 10NES was patented under U.S. Patent 4,799,635 and the source code was copyrighted; only Nintendo could produce the authorization chips. The patent covering the 10NES expired on January 24, 2006, although the copyright is still in effect.

[edit] Circumvention

Most unlicensed companies created circuits that used a voltage spike to knock the authentication unit in the NES offline.

A few unlicensed games released in Europe and Australia (such as HES games) came in the form of a dongle that would be connected to a licensed cartridge, in order to use that cartridge's 10NES lockout chip for authentication.

Tengen (Atari’s NES games subsidiary) took a different tactic: the corporation obtained a description of the code in the lockout chip from the United States Patent and Trademark Office by falsely claiming that it was required to defend against present infringement claims in a legal case. Tengen then used these documents to design their Rabbit chip, which duplicated the function of the 10NES. Nintendo sued Tengen for these actions. The court found that Tengen did not violate the copyright for copying the portion of code necessary to defeat the protection with current NES consoles, but did violate the copyright for copying portions of the code not being used in the communication between the chip and console. Tengen had copied this code in its entirety because future console releases could have been engineered to pick up the discrepancy. On the initial claim, the court sided with Nintendo on the issue of patent infringement, but noted that Nintendo’s patent would likely be deemed obvious as it was basically U.S. Patent 4,736,419 with the addition of a reset pin, which was at the time already commonplace in the world of electronics. Therefore, while Nintendo was the winner of the initial trial, before they could actually enforce the ruling they would need to have the patent hold up under scrutiny, as well as address Tengen’s antitrust claims. Before this occurred, the sides settled.

A small company called RetroZone, the first company to publish games on the NES in over a decade, uses a multi-region lockout chip for NTSC, PAL A, PAL B called the Ciclone which was created by reverse engineering Tengen's "Rabbit" chip. It is the only lockout chip in existence that will allow games to be played in more than one region. The number of titles available are small, but unlike all other unlicensed games, the cartridges are shaped exactly like licensed NES cartridges and they come in several different colors such as translucent red, blue, and green, or a clear see-through cart. They use phillips head screws instead of the standard cartridge bolts to hold them together. It is intended to make the games playable on older hardware that use 10NES lockout and the two other regions, although the NES2 does not use a lock out chip. The Ciclone chip is the first lockout chip to be developed after the patent for the 10NES chip had expired.

[edit] See also

[edit] References

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